The following specimen table has been gi_A Dictionary of Arts, Manufactures and Mines containing a clear exposition of their principles and practice

+-------------------------------++----------------------------+

| Temperature 45°. || Temperature 75°. |

+--------------+---------+------++-----------+---------+------+

|Indication.[3]|Strength.|Value.||Indication.|Strength.|Value.|

+--------------+---------+------++-----------+---------+------+

| 9074 | 114·5 | || 8941 | 114·5 | |

| 7 | 114·3 | || 4 | 114·3 | |

| 9 | 114·2 | || 5 | 114·2 | |

| 81 | 114·0 | || 8 | 114·0 | |

| 3 | 113·9 | || 9 | 113·9 | |

| 5 | 113·7 | || 52 | 113·7 | |

| 6 | 113·6 | || 3 | 113·6 | |

| 9 | 113·4 | || 6 | 113·4 | |

| 90 | 113·3 | || 7 | 113·3 | |

| 3 | 113·1 | || 9 | 113·1 | |

+--------------+---------+------++-----------+---------+------+

[3] By specific gravity.

The mixture of alcohol and water, taken as spirit in Mr. Gilpin’s

tables, is that of which the specific gravity is 0·825 at 60° Fahr.,

water being unity at the same temperature. The specific gravity of water

at 60° being 1000, at 62° it is 99,981. Hence, in order to compare the

specific gravities given by Mr. Gilpin with those which would result

when the specific gravity of water at 62° is taken at unity, all the

former numbers must be divided by 99,981.

Table of the Specific Gravities of different Mixtures, by Weight, of

Alcohol and Water, at different Temperatures; constructed by Mr. Gilpin,

for the use of the British Revenue on Spirits.

+------+-------+-------+-------+-------+-------+-------+-------+

|Tem- | Pure | 100 | 100 | 100 | 100 | 100 | 100 |

|ture, | hol. | 5 | 10 | 15 | 20 | 25 | 30 |

+------+-------+-------+-------+-------+-------+-------+-------+

|_Deg._| | | | | | | |

| 30 |0·83896|0·84995|0·85957|0·86825|0·87585|0·88282|0·88921|

| 35 | ·83672| ·84769| ·85729| ·86587| ·87357| ·88059| ·88701|

| 40 | ·83445| ·84539| ·85507| ·86361| ·87184| ·87838| ·88481|

| 45 | ·83214| ·84310| ·85277| ·86131| ·86905| ·87613| ·88255|

| 50 | ·82977| ·84076| ·85042| ·85902| ·86676| ·87384| ·88030|

| 55 | ·82736| ·83834| ·84802| ·85664| ·86441| ·87150| ·87796|

| 60 | ·82500| ·83599| ·84568| ·85430| ·86208| ·86918| ·87569|

| 65 | ·82262| ·83362| ·84334| ·85193| ·85976| ·86686| ·87337|

| 70 | ·82023| ·83124| ·84092| ·84951| ·85736| ·86451| ·87105|

| 75 | ·81780| ·82878| ·83851| ·84710| ·85496| ·86212| ·86864|

| 80 | ·81530| ·82631| ·83603| ·84467| ·85248| ·85966| ·86622|

| 85 | ·81291| ·82396| ·83371| ·84243| ·85036| ·85757| ·86411|

| 90 | ·81044| ·82150| ·83126| ·84001| ·84797| ·85518| ·86172|

| 95 | ·80794| ·81900| ·82877| ·83753| ·84550| ·85272| ·85928|

| 100 | ·80548| ·81657| ·82630| ·83513| ·84038| ·85031| ·85688|

+------+-------+-------+-------+-------+-------+-------+-------+

+------+-------+-------+-------+-------+--------+-------+-------+

|Tem- | 100 | 100 | 100 | 100 | 100 | 100 | 100 |

|ture, | 35 | 40 | 45 | 50 | 55 | 60 | 65 |

+------+-------+-------+-------+-------+--------+-------+-------+

|_Deg._| | | | | | | |

| 30 |0·89511|0·90054|0·90558|0·91023|0·91449 |0·91847|0·92217|

| 35 | ·89294| ·89839| ·90345| ·90811| ·91241 | ·91640| ·92009|

| 40 | ·89073| ·89617| ·90127| ·90596| ·91026 | ·91428| ·91799|

| 45 | ·88849| ·89396| ·89909| ·90380| ·90812 | ·91211| ·91584|

| 50 | ·88626| ·89174| ·89684| ·90160| ·90596 | ·90997| ·91370|

| 55 | ·88393| ·88945| ·89458| ·89933| ·90367 | ·90768| ·91144|

| 60 | ·88169| ·88720| ·89232| ·89707| ·90144 | ·90549| ·90927|

| 65 | ·87938| ·88490| ·89006| ·89479| ·89920 | ·90328| ·90707|

| 70 | ·87705| ·88254| ·88773| ·89252| ·89695 | ·90104| ·90484|

| 75 | ·87466| ·88018| ·88538| ·89018| ·89464 | ·89872| ·90252|

| 80 | ·87228| ·87776| ·88301| ·88781| ·89225 | ·89639| ·90021|

| 85 | ·87021| ·87590| ·88120| ·88609| ·89043 | ·89460| ·89843|

| 90 | ·86787| ·87360| ·87889| ·88376| ·88817 | ·89230| ·89617|

| 95 | ·86542| ·87114| ·87654| ·88146| ·88588 | ·89003| ·89390|

| 100 | ·86302| ·86879| ·87421| ·87915| ·883671| ·88769| ·89158|

+------+-------+-------+-------+-------+--------+-------+-------+

+------+-------+-------+-------+-------+-------+-------+-------+

|Tem- | 100 | 100 | 100 | 100 | 100 | 100 | 100 |

|ture, | 70 | 75 | 80 | 85 | 90 | 95 | 100 |

+------+-------+-------+-------+-------+-------+-------+-------+

|_Deg._| | | | | | | |

| 30 |0·92563|0·92889|0·93191|0·93474|0·93741|0·93991|0·94222|

| 35 | ·92355| ·92680| ·92986| ·93274| ·93541| ·93790| ·94025|

| 40 | ·92151| ·92476| ·92783| ·93072| ·93341| ·93592| ·93827|

| 45 | ·91937| ·92264| ·92570| ·92859| ·93131| ·93382| ·93621|

| 50 | ·91723| ·92051| ·92358| ·92647| ·92919| ·93177| ·93419|

| 55 | ·91502| ·91837| ·92145| ·92436| ·92707| ·92963| ·93208|

| 60 | ·91287| ·91622| ·91933| ·92225| ·92499| ·92758| ·93002|

| 65 | ·91066| ·91400| ·91715| ·92010| ·92283| ·92546| ·92794|

| 70 | ·90847| ·91181| ·91493| ·91793| ·92069| ·92333| ·92580|

| 75 | ·90617| ·90952| ·91270| ·91569| ·91849| ·92111| ·92364|

| 80 | ·90385| ·90723| ·91046| ·91340| ·91622| ·91891| ·92142|

| 85 | ·90209| ·90558| ·90882| ·91186| ·91465| ·91729| ·91969|

| 90 | ·89988| ·90342| ·90688| ·90967| ·91248| ·91511| ·91751|

| 95 | ·89763| ·90119| ·90443| ·90747| ·91029| ·91290| ·91531|

| 100 | ·89536| ·89889| ·90215| ·90522| ·90805| ·91066| ·91310|

+------+-------+-------+-------+-------+-------+-------+-------+

|Tem- | 95 | 90 | 85 | 80 | 75 | 70 | 65 |

|ture, | 100 | 100 | 100 | 100 | 100 | 100 | 100 |

+------+-------+-------+-------+-------+-------+-------+-------+

|_Deg._| | | | | | | |

| 30 |0·94447|0·94675|0·94920|0·95173|0·95429|0·95681|0·95944|

| 35 | ·94249| ·94484| ·94734| ·94988| ·95246| ·95502| ·95772|

| 40 | ·94058| ·94295| ·94547| ·94802| ·95060| ·95328| ·95602|

| 45 | ·93860| ·94096| ·94348| ·94605| ·94871| ·95143| ·95423|

| 50 | ·93658| ·93897| ·94149| ·94414| ·94683| ·94958| ·95243|

| 55 | ·93452| ·93696| ·93948| ·94213| ·94486| ·94767| ·95057|

| 60 | ·93247| ·93493| ·93749| ·94018| ·94296| ·94579| ·94876|

| 65 | ·93040| ·93285| ·93546| ·93822| ·94099| ·94388| ·94689|

| 70 | ·92828| ·93076| ·93337| ·93616| ·93898| ·94193| ·94500|

| 75 | ·92613| ·92865| ·93132| ·93413| ·93695| ·93989| ·94301|

| 80 | ·92393| ·92646| ·92917| ·93201| ·93488| ·93785| ·94102|

+------+-------+-------+-------+-------+-------+-------+-------+

|Tem- | 60 | 55 | 50 | 45 | 40 | 35 | 30 |

|ture, | 100 | 100 | 100 | 100 | 100 | 100 | 100 |

+------+-------+-------+-------+-------+-------+-------+-------+

|_Deg._| | | | | | | |

| 30 |0·96209|0·96470|0·96719|0·96967|0·97200|0·97418|0·97635|

| 35 | ·96048| ·96315| ·96579| ·96840| ·97086| ·97319| ·97556|

| 40 | ·95879| ·96159| ·96434| ·96706| ·96967| ·97220| ·97472|

| 45 | ·95703| ·95993| ·96280| ·96563| ·96840| ·97110| ·97384|

| 50 | ·95534| ·95831| ·96126| ·96420| ·96708| ·96995| ·97284|

| 55 | ·95357| ·95662| ·95966| ·96272| ·96575| ·96877| ·97181|

| 60 | ·95181| ·95493| ·95804| ·96122| ·96437| ·96752| ·97074|

| 65 | ·95000| ·95318| ·95635| ·95962| ·96288| ·96620| ·96959|

| 70 | ·94813| ·95139| ·95469| ·95802| ·96143| ·96484| ·96836|

| 75 | ·94623| ·94957| ·95292| ·95638| ·95987| ·96344| ·96708|

| 80 | ·94431| ·94768| ·95111| ·95467| ·95826| ·96192| ·96568|

+------+-------+-------+-------+-------+-------+-------+-------+

+------+-------+-------+-------+-------+-------+

|Tem- | 25 | 20 | 15 | 10 | 5 |

|ture, | 100 | 100 | 100 | 100 | 100 |

+------+-------+-------+-------+-------+-------+

|_Deg._| | | | | |

| 30 |0·97860|0·98108|0·98412|0·98804|0·99334|

| 35 | ·97801| ·98076| ·98397| ·98804| ·99344|

| 40 | ·97737| ·98033| ·98373| ·98795| ·99345|

| 45 | ·97666| ·97980| ·98338| ·98774| ·99338|

| 50 | ·97589| ·97920| ·98293| ·98745| ·99316|

| 55 | ·97500| ·97847| ·98239| ·98702| ·99284|

| 60 | ·97410| ·97771| ·98176| ·98654| ·99244|

| 65 | ·97309| ·97688| ·98106| ·98594| ·99194|

| 70 | ·97203| ·97596| ·98028| ·98527| ·99134|

| 75 | ·97086| ·97495| ·97943| ·98454| ·99066|

| 80 | ·96963| ·97385| ·97845| ·98367| ·98991|

+------+-------+-------+-------+-------+-------+

Experiments were made, by direction of the committee, to verify Gilpin’s

tables, which showed that the error introduced in ascertaining the

strength of spirits by tables founded on Gilpin’s numbers must be quite

insensible in the practice of the revenue. The discrepancies thus

detected, on a mixture of a given strength, did not amount in any one

instance to unity in the fourth place of decimals. From a careful

inspection of such documents the committee are of opinion, that Gilpin’s

tables possess a degree of accuracy far surpassing what could be

expected, and sufficiently perfect for all practical or scientific

purposes.

The following table is given by Mr. Lubbock, for converting the

_apparent_ specific gravity, or _indication_, into true specific

gravity:--

+-----+-----------------------------------------+-----+

|Indi-| - Temperature + |Indi-|

| ca- +------+------+------+------+------+------+ ca- |

|tion.| 30° | 32° | 37° | 42° | 47° | 52° |tion.|

+-----+------+------+------+------+------+------+-----+

| ·82 |·00083|·00078|·00065|·00052|·00039|·00025| ·82 |

| ·83 |·00084|·00079|·00066|·00052|·00039|·00026| ·83 |

| ·84 |·00085|·00080|·00066|·00053|·00039|·00026| ·84 |

| ·85 |·00086|·00081|·00067|·00054|·00040|·00026| ·85 |

| ·86 |·00087|·00082|·00068|·00054|·00040|·00027| ·86 |

| ·87 |·00088|·00083|·00069|·00055|·00041|·00027| ·87 |

| ·88 |·00089|·00084|·00070|·00055|·00041|·00027| ·88 |

| ·89 |·00090|·00085|·00070|·00055|·00042|·00028| ·89 |

| ·90 |·00091|·00085|·00071|·00056|·00042|·00028| ·90 |

| ·91 |·00092|·00086|·00072|·00057|·00043|·00028| ·91 |

| ·92 |·00093|·00087|·00073|·00058|·00043|·00029| ·92 |

| ·93 |·00094|·00088|·00073|·00059|·00044|·00029| ·93 |

| ·94 |·00095|·00089|·00074|·00059|·00044|·00029| ·94 |

| ·95 |·00096|·00090|·00075|·00060|·00045|·00029| ·95 |

| ·96 |·00097|·00091|·00076|·00060|·00045|·00030| ·96 |

| ·97 |·00098|·00092|·00077|·00061|·00046|·00030| ·97 |

| ·98 |·00099|·00093|·00077|·00062|·00046|·00030| ·98 |

| ·99 |·00100|·00094|·00078|·00062|·00047|·00031| ·99 |

|1·00 |·00101|·00095|·00079|·00063|·00047|·00031|1·00 |

+-----+------+------+------+------+------+------+-----+

+-----+-----------------------------------------+-----+

|Indi-| - Temperature + |Indi-|

| ca- +------+------+------+------+------+------+ ca- |

|tion.| 57° | 62° | 67° | 72° | 77° | 80° |tion.|

+-----+------+------+------+------+------+------+-----+

| ·82 |·00012| |·00011|·00024|·00035|·00042| ·82 |

| ·83 |·00012| |·00012|·00024|·00036|·00042| ·83 |

| ·84 |·00013| |·00012|·00024|·00036|·00043| ·84 |

| ·85 |·00013| |·00012|·00025|·00037|·00043| ·85 |

| ·86 |·00013| |·00012|·00025|·00037|·00044| ·86 |

| ·87 |·00013| |·00012|·00025|·00037|·00044| ·87 |

| ·88 |·00013| |·00012|·00026|·00038|·00045| ·88 |

| ·89 |·00013| |·00012|·00026|·00038|·00045| ·89 |

| ·90 |·00014| |·00013|·00026|·00039|·00046| ·90 |

| ·91 |·00014| |·00013|·00026|·00039|·00046| ·91 |

| ·92 |·00014| |·00013|·00027|·00040|·00047| ·92 |

| ·93 |·00014| |·00013|·00027|·00040|·00047| ·93 |

| ·94 |·00014| |·00013|·00027|·00040|·00048| ·94 |

| ·95 |·00014| |·00013|·00028|·00041|·00048| ·95 |

| ·96 |·00014| |·00013|·00028|·00041|·00049| ·96 |

| ·97 |·00015| |·00014|·00028|·00042|·00049| ·97 |

| ·98 |·00015| |·00014|·00028|·00042|·00050| ·98 |

| ·99 |·00015| |·00014|·00029|·00043|·00050| ·99 |

|1·00 |·00015| | | | | |1·00 |

+-----+------+------+------+------+------+------+-----+

[Illustration: _Fig._ 5.]

The hydrometer constructed, under the directions of the Commissioners of

Excise, by Mr. Bate, has a scale of 4 inches in length divided into 100

parts, and 9 weights. It has thus a range of 900 divisions, and

expresses specific gravities at the temperature of 62° Fahr. In order to

render this instrument so accurate a measurer of the specific gravity,

at the standard temperature, as to involve no error of an appreciable

amount, Mr. Bate has constructed the weights (which in this instrument

are immersed in the fluid of different specific gravities) so that each

successive weight should have an increase of bulk over the preceding

weight equal to that part of the stem occupied by the scale, and an

increase of weight sufficient to take the whole of the scale, and no

more, down to the liquid. This arrangement requires great accuracy of

workmanship, and enhances the price of the instrument. But it allows of

increased strength in the ball, where it is very much required, and it

gives, upon inspection only, the indication (apparent specific gravity)

by which the general table is to be examined and the result ascertained.

_Fig._ 5. represents this instrument and two of its nine ballast

weights. It comprehends all specific gravities between 820 and 1000. It

indicates true specific gravity with almost perfect accuracy at the

temperature of 62° Fahr.; but it does not exclude other instruments from

being used in conjunction with tables. The latter are, in fact,

independent of the instrument, and may be used with gravimeters, or any

instrument affording indications by specific gravity at a given

temperature.

The commercial value of spirituous liquors being much lower in France

than in England, a less sensible instrument becomes sufficient for the

wants of that country. Baumé’s and Cartier’s hydrometers, with short

arbitrary scales, are very much employed, but they have been lately

superseded by an ingenious and ready instrument contrived by M. Gay

Lussac, and called by him an _alcoomètre_. He takes for the term of

comparison pure alcohol by volume, at the temperature of 15° Cent., and

represents the strength of it by 100 _centimes_, or by unity.

Consequently, the strength of a spirituous liquid is the number of

centimes in volume of pure alcohol which that liquid contains at the

temperature of 15° Cent. The instrument is formed like a common

hydrometer, and is graduated for the temperature of 15° Cent. Its scale

is divided into 100 parts or degrees, each of which denotes a centime of

alcohol; the division 0 at the bottom of the stem corresponds to pure

water, and the division 100 at its top, to pure alcohol. When immersed

in a spirituous liquor at 15° Cent. (59° Fahr.) it announces its

strength directly. For example: if in spirits supposed at the

temperature of 15° Cent. it sinks to the division 50, it indicates that

the strength of this liquor is 50 per cent., or that it contains 50

centimes of pure alcohol. In our new British proof spirit, it would sink

to nearly 57, indicating 57 by volume of pure alcohol, allowing for

condensation, or 50 by weight. A table of correction is given for

temperature, which he calls “Table of real strength of spirituous

liquors.” The first vertical column of this table contains the

temperatures, from 0° to 30° Cent., and the first horizontal line the

indications of the alcoomètre. In the same table we have most

ingeniously inserted a correction for the volume of the spirits when the

temperature differs from 15° Cent. If we take 1000 litres or gallons,

measured at the temperature of 2°, of a spirituous liquor whose apparent

strength is 44^{c}; its real strength at 15° will from the preceding

mode of correction be 49^{c}. On heating this liquid to 15°, in order to

find its real specific gravity or strength, its bulk will become

greater; and, instead of 1000 litres or gallons, which it measured at

2°, we shall have 1009 at 15° C. This number is inscribed in smaller

characters in the same square cell with the real force, precisely under

49^{c}. All the numbers in small characters, printed under each _real

strength_, indicate the volume which 1000 litres of a spirituous liquor

would have, when measured at the temperature at which its apparent

strength is taken. In the above example, the quantity in litres or

gallons of pure alcohol contained in 1000 litres or gallons of the

spirits, measured at the temperature of 2°, will be, therefore,--1009

lit. × 0·49 = 494 lit. 41.

This quantity of pure alcohol, thus estimated, is called _richness of

spirit in alcohol_, or simply _richness_.

Let us take an example similar to the preceding, but at a higher

temperature than 15° Cent. Suppose we have 1000 litres measured, at the

temperature of 25°, of spirits whose apparent strength is 53^{c}, what

is the real quantity of pure alcohol which this spirit contains at the

temperature of 15°? We shall find in the table, first of all, that the

real strength of the spirits is 49^{c}·3. As to its bulk or volume, it

is very clear that the 1000 litres in cooling from 25° to 15°, will

occupy a smaller space. This volume will be 993 litres; it is inscribed

directly below 49^{c}·3, the real strength. We shall therefore have of

pure alcohol, contained in the 1000 litres of spirits, measured at the

temperature of 25°, or their _richness_, 993 lit. × 0·493 = 489 lit. 55.

Alcometrical Table of real Strength, by M. Gay Lussac.

+-------+------+------+------+------+------+------+------+------+

|Temper-|31^{c}|32^{c}|33^{c}|34^{c}|35^{c}|36^{c}|37^{c}|38^{c}|

| C. | | | | | | | | |

+-------+------+------+------+------+------+------+------+------+

| _Deg._| | | | | | | | |

| 10 | 33·0 | 34 | 35 | 36 | 37 | 38 | 39 | 40 |

| | 1002 | 1002 | 1003 | 1003 | 1003 | 1003 | 1003 | 1003 |

| +------+------+------+------+------+------+------+------+

| 11 | 32·6 | 33·6 | 34·6 | 35·6 | 36·6 | 37·6 | 38·6 | 39·6 |

| | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 |

| +------+------+------+------+------+------+------+------+

| 12 | 32·2 | 33·2 | 34·2 | 35·2 | 36·2 | 37·2 | 38·2 | 39·2 |

| | 1001 | 1001 | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 |

| +------+------+------+------+------+------+------+------+

| 13 | 31·8 | 32·8 | 33·8 | 34·8 | 35·8 | 36·8 | 37·8 | 38·8 |

| | 1001 | 1001 | 1001 | 1001 | 1001 | 1001 | 1001 | 1001 |

| +------+------+------+------+------+------+------+------+

| 14 | 31·4 | 32·4 | 33·4 | 34·4 | 35·4 | 36·4 | 37·4 | 38·4 |

| | 1001 | 1001 | 1001 | 1001 | 1001 | 1001 | 1001 | 1001 |

| +------+------+------+------+------+------+------+------+

| 15 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 |

| | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 |

| +------+------+------+------+------+------+------+------+

| 16 | 30·6 | 31·6 | 32·5 | 33·5 | 34·5 | 35·5 | 36·5 | 37·5 |

| | 1000 | 1000 | 999 | 999 | 999 | 999 | 999 | 999 |

| +------+------+------+------+------+------+------+------+

| 17 | 30·2 | 31·2 | 32·1 | 33·1 | 34·1 | 35·1 | 36·1 | 37·1 |

| | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 |

| +------+------+------+------+------+------+------+------+

| 18 | 29·8 | 30·8 | 31·7 | 32·7 | 33·7 | 34·7 | 35·7 | 36·7 |

| | 999 | 999 | 998 | 998 | 998 | 998 | 998 | 998 |

| +------+------+------+------+------+------+------+------+

| 19 | 29·4 | 30·4 | 31·3 | 32·3 | 33·3 | 34·3 | 35·3 | 36·3 |

| | 998 | 998 | 998 | 998 | 998 | 998 | 998 | 998 |

| +------+------+------+------+------+------+------+------+

| 20 | 29 | 30 | 30·9 | 31·9 | 32·9 | 33·9 | 34·9 | 35·9 |

| | 998 | 998 | 997 | 997 | 997 | 997 | 997 | 997 |

| +------+------+------+------+------+------+------+------+

| 21 | 28·6 | 29·6 | 30·5 | 31·5 | 32·5 | 33·5 | 34·5 | 35·5 |

| | 997 | 997 | 997 | 997 | 997 | 997 | 997 | 996 |

| +------+------+------+------+------+------+------+------+

| 22 | 28·2 | 29·2 | 30·1 | 31·1 | 32·1 | 33·1 | 34·1 | 35·1 |

| | 997 | 997 | 996 | 996 | 996 | 996 | 996 | 996 |

| +------+------+------+------+------+------+------+------+

| 23 | 27·8 | 28·8 | 29·7 | 30·7 | 31·7 | 32·7 | 33·7 | 34·7 |

| | 996 | 996 | 996 | 996 | 996 | 996 | 996 | 995 |

| +------+------+------+------+------+------+------+------+

| 24 | 27·4 | 28·4 | 29·3 | 30·3 | 31·3 | 32·3 | 33·3 | 34·3 |

| | 996 | 996 | 995 | 995 | 995 | 995 | 995 | 995 |

| +------+------+------+------+------+------+------+------+

| 25 | 27 | 28 | 28·9 | 29·9 | 30·9 | 31·9 | 32·9 | 33·9 |

| | 995 | 995 | 995 | 995 | 995 | 994 | 994 | 994 |

+-------+------+------+------+------+------+------+------+------+

|Temper-|39^{c}|40^{c}|41^{c}|42^{c}|43^{c}|44^{c}|45^{c}|46^{c}|

| C. | | | | | | | | |

+-------+------+------+------+------+------+------+------+------+

| _Deg._| | | | | | | | |

| 10 | 41 | 42 | 43 | 44 | 45 | 46 | 46·9 | 47·9 |

| | 1003 | 1003 | 1003 | 1004 | 1004 | 1004 | 1004 | 1004 |

| +------+------+------+------+------+------+------+------+

| 11 | 40·6 | 41·6 | 42·6 | 43·6 | 44·6 | 45·6 | 46·6 | 47·6 |

| | 1003 | 1003 | 1003 | 1003 | 1003 | 1003 | 1003 | 1003 |

| +------+------+------+------+------+------+------+------+

| 12 | 40·2 | 41·2 | 42·2 | 43·2 | 44·2 | 45·2 | 46·2 | 47·2 |

| | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 |

| +------+------+------+------+------+------+------+------+

| 13 | 39·8 | 40·8 | 41·8 | 42·8 | 43·8 | 44·8 | 45·8 | 46·8 |

| | 1001 | 1001 | 1001 | 1001 | 1001 | 1002 | 1002 | 1002 |

| +------+------+------+------+------+------+------+------+

| 14 | 39·4 | 40·4 | 41·4 | 42·4 | 43·4 | 44·4 | 45·4 | 46·4 |

| | 1001 | 1001 | 1001 | 1001 | 1001 | 1001 | 1001 | 1001 |

| +------+------+------+------+------+------+------+------+

| 15 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 |

| | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 |

| +------+------+------+------+------+------+------+------+

| 16 | 38·5 | 39·5 | 40·6 | 41·6 | 42·6 | 43·6 | 44·6 | 45·6 |

| | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 |

| +------+------+------+------+------+------+------+------+

| 17 | 38·1 | 39·1 | 40·2 | 41·2 | 42·2 | 43·2 | 44·9 | 45·2 |

| | 999 | 999 | 999 | 999 | 999 | 998 | 998 | 998 |

| +------+------+------+------+------+------+------+------+

| 18 | 37·7 | 38·7 | 39·8 | 40·8 | 41·8 | 42·8 | 43·8 | 44·9 |

| | 998 | 998 | 998 | 998 | 998 | 998 | 998 | 998 |

| +------+------+------+------+------+------+------+------+

| 19 | 37·3 | 38·3 | 39·4 | 40·4 | 41·4 | 42·5 | 43·5 | 44·5 |

| | 997 | 997 | 997 | 997 | 997 | 997 | 997 | 997 |

| +------+------+------+------+------+------+------+------+

| 20 | 36·9 | 37·9 | 39 | 40 | 41 | 42·1 | 43·1 | 44·1 |

| | 997 | 997 | 997 | 997 | 997 | 997 | 996 | 996 |

| +------+------+------+------+------+------+------+------+

| 21 | 36·5 | 37·5 | 38·6 | 39·6 | 40·6 | 41·7 | 42·7 | 43·7 |

| | 996 | 996 | 996 | 996 | 996 | 996 | 996 | 996 |

| +------+------+------+------+------+------+------+------+

| 22 | 36·1 | 37·1 | 38·2 | 39·2 | 40·2 | 41·3 | 42·3 | 43·3 |

| | 996 | 996 | 996 | 995 | 995 | 995 | 995 | 995 |

| +------+------+------+------+------+------+------+------+

| 23 | 35·7 | 36·7 | 37·8 | 38·8 | 39·8 | 40·9 | 41·9 | 42·9 |

| | 995 | 995 | 995 | 995 | 995 | 994 | 994 | 994 |

| +------+------+------+------+------+------+------+------+

| 24 | 35·3 | 36·3 | 37·4 | 38·4 | 39·4 | 40·5 | 41·5 | 42·5 |

| | 995 | 994 | 994 | 994 | 994 | 994 | 994 | 994 |

| +------+------+------+------+------+------+------+------+

| 25 | 34·9 | 35·9 | 37 | 38 | 39 | 40·1 | 42·1 | 42·2 |

| | 994 | 994 | 994 | 994 | 993 | 993 | 993 | 993 |

+-------+------+------+------+------+------+------+------+------+

|Temper-|47^{c}|48^{c}|49^{c}|50^{c}|51^{c}|52^{c}|53^{c}|54^{c}|

| C. | | | | | | | | |

+-------+------+------+------+------+------+------+------+------+

| _Deg._| | | | | | | | |

| 10 | 48·9 | 49·9 | 50·9 | 51·8 | 52·8 | 53·8 | 54·8 | 55·8 |

| | 1004 | 1004 | 1004 | 1004 | 1004 | 1004 | 1004 | 1004 |

| +------+------+------+------+------+------+------+------+

| 11 | 48·6 | 49·5 | 50·5 | 51·5 | 52·5 | 53·5 | 54·4 | 55·4 |

| | 1003 | 1003 | 1003 | 1003 | 1003 | 1003 | 1003 | 1003 |

| +------+------+------+------+------+------+------+------+

| 12 | 48·2 | 49·2 | 50·2 | 51·1 | 52·1 | 53·1 | 54·1 | 55 |

| | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 |

| +------+------+------+------+------+------+------+------+

| 13 | 47·8 | 48·8 | 49·8 | 50·8 | 51·8 | 52·7 | 53·7 | 54·7 |

| | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 |

| +------+------+------+------+------+------+------+------+

| 14 | 47·4 | 48·4 | 49·4 | 50·4 | 51·4 | 52·3 | 53·3 | 54·3 |

| | 1001 | 1001 | 1001 | 1000 | 1001 | 1001 | 1001 | 1001 |

| +------+------+------+------+------+------+------+------+

| 15 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 |

| | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 |

| +------+------+------+------+------+------+------+------+

| 16 | 46·6 | 47·6 | 48·6 | 49·6 | 50·6 | 51·6 | 52·6 | 53·6 |

| | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 |

| +------+------+------+------+------+------+------+------+

| 17 | 46·2 | 47·2 | 48·2 | 49·2 | 50·3 | 51·3 | 52·3 | 53·3 |

| | 998 | 998 | 998 | 998 | 998 | 998 | 998 | 998 |

| +------+------+------+------+------+------+------+------+

| 18 | 45·9 | 46·9 | 47·9 | 48·9 | 49·9 | 50·9 | 51·9 | 52·9 |

| | 998 | 998 | 998 | 998 | 998 | 998 | 998 | 998 |

| +------+------+------+------+------+------+------+------+

| 19 | 45·5 | 46·5 | 47·5 | 48·5 | 49·5 | 50·6 | 51·6 | 52·6 |

| | 997 | 997 | 997 | 997 | 997 | 997 | 997 | 997 |

| +------+------+------+------+------+------+------+------+

| 20 | 45·1 | 46·1 | 47·2 | 48·2 | 49·2 | 50·2 | 51·2 | 52·2 |

| | 996 | 996 | 996 | 996 | 996 | 996 | 996 | 996 |

| +------+------+------+------+------+------+------+------+

| 21 | 44·8 | 45·8 | 46·8 | 47·8 | 48·8 | 49·8 | 50·8 | 51·8 |

| | 996 | 996 | 995 | 995 | 995 | 995 | 995 | 995 |

| +------+------+------+------+------+------+------+------+

| 22 | 44·3 | 45·3 | 46·4 | 47·4 | 48·4 | 49·4 | 50·4 | 51·4 |

| | 995 | 995 | 995 | 995 | 995 | 995 | 995 | 994 |

| +------+------+------+------+------+------+------+------+

| 23 | 43·9 | 44·9 | 46 | 47 | 48 | 49·1 | 50·1 | 51·1 |

| | 994 | 994 | 994 | 994 | 994 | 994 | 994 | 994 |

| +------+------+------+------+------+------+------+------+

| 24 | 43·6 | 44·6 | 45·6 | 46·6 | 47·6 | 48·7 | 49·7 | 50·7 |

| | 994 | 994 | 993 | 993 | 993 | 993 | 993 | 693 |

| +------+------+------+------+------+------+------+------+

| 25 | 43·2 | 44·2 | 45·2 | 46·3 | 47·3 | 48·3 | 49·3 | 50·3 |

| | 993 | 993 | 993 | 993 | 993 | 993 | 993 | 992 |

+-------+------+------+------+------+------+------+------+------+

|Temper-|55^{c}|56^{c}|57^{c}|58^{c}|59^{c}|60^{c}|61^{c}|62^{c}|

| C. | | | | | | | | |

+-------+------+------+------+------+------+------+------+------+

| _Deg._| | | | | | | | |

| 10 | 56·8 | 57·8 | 58·8 | 59·7 | 60·7 | 61·7 | 62·7 | 63·7 |

| | 1004 | 1004 | 1004 | 1004 | 1004 | 1004 | 1004 | 1004 |

| +------+------+------+------+------+------+------+------+

| 11 | 56·4 | 57·4 | 58·4 | 59·4 | 60·4 | 61·4 | 62·4 | 63·4 |

| | 1003 | 1003 | 1003 | 1003 | 1003 | 1003 | 1003 | 1003 |

| +------+------+------+------+------+------+------+------+

| 12 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 |

| | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 |

| +------+------+------+------+------+------+------+------+

| 13 | 55·7 | 56·7 | 57·7 | 58·7 | 59·7 | 60·7 | 61·7 | 62·7 |

| | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 |

| +------+------+------+------+------+------+------+------+

| 14 | 55·3 | 56·3 | 57·3 | 58·3 | 59·3 | 60·3 | 61·3 | 62·3 |

| | 1001 | 1001 | 1001 | 1001 | 1001 | 1001 | 1001 | 1001 |

| +------+------+------+------+------+------+------+------+

| 15 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 |

| | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 |

| +------+------+------+------+------+------+------+------+

| 16 | 54·6 | 55·6 | 56·6 | 57·6 | 58·6 | 59·6 | 60·6 | 61·7 |

| | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 |

| +------+------+------+------+------+------+------+------+

| 17 | 54·3 | 55·3 | 56·3 | 57·3 | 58·3 | 59·3 | 60·3 | 61·3 |

| | 998 | 998 | 998 | 998 | 998 | 998 | 998 | 998 |

| +------+------+------+------+------+------+------+------+

| 18 | 53·9 | 54·9 | 55·9 | 56·9 | 57·9 | 58·9 | 59·9 | 61 |

| | 998 | 998 | 998 | 997 | 997 | 997 | 997 | 997 |

| +------+------+------+------+------+------+------+------+

| 19 | 53·6 | 54·6 | 55·6 | 56·6 | 57·6 | 58·6 | 59·6 | 60·6 |

| | 997 | 997 | 997 | 997 | 997 | 997 | 997 | 997 |

| +------+------+------+------+------+------+------+------+

| 20 | 53·2 | 54·2 | 55·2 | 56·2 | 57·2 | 58·2 | 59·2 | 60·3 |

| | 996 | 996 | 996 | 996 | 996 | 996 | 996 | 996 |

| +------+------+------+------+------+------+------+------+

| 21 | 52·9 | 53·9 | 54·9 | 55·9 | 56·9 | 57·9 | 58·9 | 59·9 |

| | 995 | 995 | 995 | 995 | 995 | 995 | 995 | 995 |

| +------+------+------+------+------+------+------+------+

| 22 | 52·5 | 53·5 | 54·5 | 55·5 | 56·5 | 57·5 | 58·5 | 59·5 |

| | 994 | 994 | 994 | 994 | 994 | 994 | 994 | 994 |

| +------+------+------+------+------+------+------+------+

| 23 | 52·1 | 53·1 | 54·1 | 55·1 | 56·1 | 57·1 | 58·1 | 59·2 |

| | 994 | 994 | 994 | 993 | 993 | 993 | 993 | 993 |

| +------+------+------+------+------+------+------+------+

| 24 | 51·8 | 52·8 | 53·8 | 54·8 | 55·8 | 56·8 | 57·8 | 58·9 |

| | 993 | 993 | 993 | 993 | 993 | 992 | 992 | 992 |

| +------+------+------+------+------+------+------+------+

| 25 | 51·4 | 52·4 | 53·4 | 54·4 | 55·5 | 56·5 | 57·5 | 58·5 |

| | 992 | 992 | 992 | 992 | 992 | 992 | 992 | 992 |

+-------+------+------+------+------+------+------+------+------+

|Temper-|63^{c}|64^{c}|65^{c}|66^{c}|67^{c}|68^{c}|69^{c}|70^{c}|

| C. | | | | | | | | |

+-------+------+------+------+------+------+------+------+------+

| _Deg._| | | | | | | | |

| 10 | 64·7 | 65·7 | 66·7 | 67·6 | 68·6 | 69·6 | 70·6 | 71·6 |

| | 1004 | 1004 | 1004 | 1004 | 1004 | 1004 | 1004 | 1004 |

| +------+------+------+------+------+------+------+------+

| 11 | 64·4 | 65·4 | 66·4 | 67·3 | 68·3 | 69·3 | 70·3 | 71·3 |

| | 1003 | 1003 | 1003 | 1003 | 1003 | 1004 | 1004 | 1004 |

| +------+------+------+------+------+------+------+------+

| 12 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 |

| | 1002 | 1002 | 1002 | 1002 | 1003 | 1003 | 1003 | 1003 |

| +------+------+------+------+------+------+------+------+

| 13 | 63·7 | 64·7 | 65·7 | 66·7 | 67·7 | 68·7 | 69·6 | 70·6 |

| | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 |

| +------+------+------+------+------+------+------+------+

| 14 | 63·3 | 64·3 | 65·3 | 66·3 | 67·3 | 68·3 | 69·3 | 70·3 |

| | 1001 | 1001 | 1001 | 1001 | 1001 | 1001 | 1001 | 1001 |

| +------+------+------+------+------+------+------+------+

| 15 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 |

| | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 |

| +------+------+------+------+------+------+------+------+

| 16 | 62·7 | 63·7 | 64·7 | 65·7 | 66·7 | 67·7 | 68·7 | 69·7 |

| | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 |

| +------+------+------+------+------+------+------+------+

| 17 | 62·3 | 63·3 | 64·3 | 65·3 | 66·3 | 67·3 | 68·3 | 69·3 |

| | 998 | 998 | 998 | 998 | 998 | 998 | 998 | 998 |

| +------+------+------+------+------+------+------+------+

| 18 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 |

| | 997 | 997 | 997 | 997 | 997 | 997 | 997 | 997 |

| +------+------+------+------+------+------+------+------+

| 19 | 61·6 | 62·7 | 63·7 | 64·7 | 65·7 | 66·7 | 67·7 | 68·7 |

| | 997 | 997 | 997 | 997 | 997 | 997 | 996 | 996 |

| +------+------+------+------+------+------+------+------+

| 20 | 61·3 | 62·3 | 63·3 | 64·3 | 65·4 | 66·4 | 67·4 | 68·4 |

| | 996 | 996 | 996 | 996 | 996 | 996 | 996 | 996 |

| +------+------+------+------+------+------+------+------+

| 21 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68·1 |

| | 995 | 995 | 995 | 995 | 995 | 995 | 995 | 995 |

| +------+------+------+------+------+------+------+------+

| 22 | 60·6 | 61·6 | 62·7 | 63·7 | 64·7 | 65·7 | 66·7 | 67·7 |

| | 994 | 994 | 994 | 994 | 994 | 994 | 994 | 994 |

| +------+------+------+------+------+------+------+------+

| 23 | 60·2 | 61·3 | 62·3 | 63·3 | 64·3 | 65·4 | 66·4 | 67·4 |

| | 993 | 993 | 993 | 993 | 993 | 993 | 993 | 993 |

| +------+------+------+------+------+------+------+------+

| 24 | 59·9 | 61 | 62 | 63 | 64 | 65 | 66 | 67·1 |

| | 992 | 992 | 992 | 992 | 992 | 992 | 992 | 992 |

| +------+------+------+------+------+------+------+------+

| 25 | 59·5 | 60·6 | 61·6 | 62·6 | 63·7 | 64·7 | 65·7 | 66·7 |

| | 992 | 991 | 991 | 991 | 991 | 991 | 991 | 991 |

+-------+------+------+------+------+------+------+------+------+

|Temper-|71^{c}|72^{c}|73^{c}|74^{c}|75^{c}|76^{c}|77^{c}|78^{c}|

| C. | | | | | | | | |

+-------+------+------+------+------+------+------+------+------+

| _Deg._| | | | | | | | |

| 10 | 72·6 | 73·5 | 74·5 | 75·5 | 76·5 | 77·5 | 78·5 | 79·5 |

| | 1004 | 1004 | 1005 | 1005 | 1005 | 1005 | 1005 | 1005 |

| +------+------+------+------+------+------+------+------+

| 11 | 72·3 | 73·2 | 74·2 | 75·2 | 76·2 | 77·2 | 78·2 | 79·2 |

| | 1004 | 1004 | 1004 | 1004 | 1004 | 1004 | 1004 | 1004 |

| +------+------+------+------+------+------+------+------+

| 12 | 72 | 72·9 | 73·9 | 74·9 | 75·9 | 76·9 | 77·9 | 78·9 |

| | 1003 | 1003 | 1003 | 1003 | 1003 | 1003 | 1003 | 1003 |

| +------+------+------+------+------+------+------+------+

| 13 | 71·6 | 72·6 | 73·6 | 74·6 | 75·6 | 76·6 | 77·6 | 78·6 |

| | 1002 | 1002 | 1002 | 1002 | 1092 | 1002 | 1002 | 1002 |

| +------+------+------+------+------+------+------+------+

| 14 | 71·3 | 72·3 | 73·3 | 74·3 | 75·3 | 76·3 | 77·3 | 78·3 |

| | 1001 | 1001 | 1001 | 1001 | 1001 | 1001 | 1001 | 1001 |

| +------+------+------+------+------+------+------+------+

| 15 | 71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 |

| | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 |

| +------+------+------+------+------+------+------+------+

| 16 | 70·7 | 71·7 | 72·7 | 73·7 | 74·7 | 75·7 | 76·7 | 77·7 |

| | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 |

| +------+------+------+------+------+------+------+------+

| 17 | 70·3 | 71·3 | 72·3 | 73·3 | 74·3 | 75·4 | 76·4 | 77·4 |

| | 998 | 998 | 998 | 998 | 998 | 998 | 998 | 998 |

| +------+------+------+------+------+------+------+------+

| 18 | 70 | 71 | 72 | 73 | 74 | 75·1 | 76·1 | 77·1 |

| | 997 | 997 | 997 | 997 | 997 | 997 | 997 | 997 |

| +------+------+------+------+------+------+------+------+

| 19 | 69·7 | 70·7 | 71·7 | 72·7 | 73·7 | 74·7 | 75·8 | 76·8 |

| | 996 | 996 | 996 | 996 | 996 | 996 | 996 | 996 |

| +------+------+------+------+------+------+------+------+

| 20 | 69·4 | 70·4 | 71·4 | 72·4 | 73·4 | 74·4 | 75·5 | 76·5 |

| | 996 | 996 | 995 | 995 | 995 | 995 | 995 | 995 |

| +------+------+------+------+------+------+------+------+

| 21 | 69·1 | 70·1 | 71·1 | 72·1 | 73·1 | 74·1 | 75·2 | 76·2 |

| | 995 | 995 | 995 | 994 | 994 | 994 | 994 | 994 |

| +------+------+------+------+------+------+------+------+

| 22 | 68·8 | 69·8 | 70·8 | 71·8 | 72·8 | 73·8 | 74·8 | 75·9 |

| | 994 | 994 | 994 | 994 | 993 | 993 | 993 | 993 |

| +------+------+------+------+------+------+------+------+

| 23 | 68·4 | 69·4 | 70·5 | 71·5 | 72·5 | 73·5 | 74·5 | 75·5 |

| | 993 | 993 | 993 | 993 | 992 | 992 | 992 | 992 |

| +------+------+------+------+------+------+------+------+

| 24 | 68·1 | 69·1 | 70·1 | 71·2 | 72·2 | 73·2 | 74·2 | 75·2 |

| | 992 | 992 | 992 | 992 | 992 | 992 | 992 | 991 |

| +------+------+------+------+------+------+------+------+

| 25 | 67·8 | 68·8 | 69·8 | 70·8 | 71·8 | 72·8 | 73·9 | 74·9 |

| | 991 | 991 | 991 | 991 | 991 | 991 | 991 | 991 |

+-------+------+------+------+------+------+------+------+------+

|Temper-|79^{c}|80^{c}|81^{c}|82^{c}|83^{c}|84^{c}|85^{c}|86^{c}|

| C. | | | | | | | | |

+-------+------+------+------+------+------+------+------+------+

| _Deg._| | | | | | | | |

| 10 | 80·5 | 81·5 | 82·4 | 83·4 | 84·4 | 85·4 | 86·4 | 87·4 |

| | 1005 | 1005 | 1005 | 1005 | 1005 | 1005 | 1005 | 1005 |

| +------+------+------+------+------+------+------+------+

| 11 | 80·2 | 81·2 | 82·2 | 83·1 | 84·1 | 85·1 | 86·1 | 87·1 |

| | 1004 | 1004 | 1004 | 1004 | 1004 | 1004 | 1004 | 1004 |

| +------+------+------+------+------+------+------+------+

| 12 | 79·9 | 80·9 | 81·9 | 82·9 | 83·9 | 84·8 | 85·8 | 86·8 |

| | 1003 | 1003 | 1003 | 1003 | 1003 | 1003 | 1003 | 1003 |

| +------+------+------+------+------+------+------+------+

| 13 | 79·6 | 80·6 | 81·6 | 82·6 | 83·6 | 84·6 | 85·5 | 86·5 |

| | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 | 1002 |

| +------+------+------+------+------+------+------+------+

| 14 | 79·3 | 80·3 | 81·3 | 82·3 | 83·3 | 84·3 | 85·3 | 86·3 |

| | 1001 | 1001 | 1001 | 1001 | 1001 | 1001 | 1001 | 1001 |

| +------+------+------+------+------+------+------+------+

| 15 | 79 | 80 | 81 | 82 | 83 | 84 | 85 | 86 |

| | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 |

| +------+------+------+------+------+------+------+------+

| 16 | 78·7 | 79·7 | 80·7 | 81·7 | 82·7 | 83·7 | 84·7 | 85·7 |

| | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 |

| +------+------+------+------+------+------+------+------+

| 17 | 78·4 | 79·4 | 80·4 | 81·4 | 82·4 | 83·4 | 84·4 | 85·4 |

| | 998 | 998 | 998 | 998 | 998 | 998 | 998 | 998 |

| +------+------+------+------+------+------+------+------+

| 18 | 78·1 | 79·1 | 80·1 | 81·1 | 82·1 | 83·1 | 84·1 | 85·2 |

| | 997 | 997 | 997 | 997 | 997 | 997 | 997 | 997 |

| +------+------+------+------+------+------+------+------+

| 19 | 77·8 | 78·8 | 79·8 | 80·8 | 81·9 | 82·9 | 83·9 | 84·9 |

| | 996 | 996 | 996 | 996 | 996 | 996 | 996 | 996 |

| +------+------+------+------+------+------+------+------+

| 20 | 77·5 | 78·5 | 79·5 | 80·5 | 81·6 | 82·6 | 83·6 | 84·6 |

| | 995 | 995 | 995 | 995 | 995 | 995 | 995 | 995 |

| +------+------+------+------+------+------+------+------+

| 21 | 77·2 | 78·2 | 79·2 | 80·2 | 81·3 | 82·3 | 83·3 | 84·3 |

| | 994 | 994 | 994 | 994 | 994 | 994 | 994 | 994 |

| +------+------+------+------+------+------+------+------+

| 22 | 76·9 | 77·9 | 78·9 | 79·9 | 81 | 82 | 83 | 84 |

| | 993 | 993 | 993 | 993 | 993 | 993 | 993 | 993 |

| +------+------+------+------+------+------+------+------+

| 23 | 76·6 | 77·6 | 78·6 | 79·6 | 80·7 | 81·7 | 82·7 | 83·8 |

| | 992 | 992 | 992 | 992 | 992 | 992 | 992 | 992 |

| +------+------+------+------+------+------+------+------+

| 24 | 76·3 | 77·3 | 78·3 | 79·3 | 80·4 | 81·4 | 82·4 | 83·5 |

| | 991 | 991 | 991 | 991 | 991 | 991 | 991 | 991 |

| +------+------+------+------+------+------+------+------+

| 25 | 76 | 77 | 78 | 79 | 80·1 | 81·1 | 82·1 | 83·2 |

| | 991 | 991 | 991 | 991 | 990 | 990 | 990 | 990 |

+-------+------+------+------+------+------+------+------+------+

+-------+------+------+------+------+

|Temper-|87^{c}|88^{c}|89^{c}|90^{c}|

| C. | | | | |

+-------+------+------+------+------+

| _Deg._| | | | |

| 10 | 88·3 | 89·3 | 90·2 | 91·2 |

| | 1005 | 1005 | 1005 | 1005 |

| +------+------+------+------+

| 11 | 88 | 89 | 90 | 91 |

| | 1004 | 1004 | 1004 | 1004 |

| +------+------+------+------+

| 12 | 87·8 | 88·7 | 89·7 | 90·7 |

| | 1003 | 1003 | 1003 | 1003 |

| +------+------+------+------+

| 13 | 87·5 | 88·5 | 89·5 | 90·5 |

| | 1002 | 1002 | 1002 | 1002 |

| +------+------+------+------+

| 14 | 87·3 | 88·2 | 89·2 | 90·2 |

| | 1001 | 1001 | 1001 | 1001 |

| +------+------+------+------+

| 15 | 87 | 88 | 89 | 90 |

| | 1000 | 1000 | 1000 | 1000 |

| +------+------+------+------+

| 16 | 86·7 | 87·7 | 88·7 | 89·7 |

| | 999 | 999 | 999 | 999 |

| +------+------+------+------+

| 17 | 86·4 | 87·4 | 88·4 | 89·5 |

| | 998 | 998 | 998 | 998 |

| +------+------+------+------+

| 18 | 86·2 | 87·2 | 88·2 | 89·2 |

| | 997 | 997 | 997 | 997 |

| +------+------+------+------+

| 19 | 85·9 | 86·9 | 87·9 | 88·9 |

| | 996 | 996 | 996 | 996 |

| +------+------+------+------+

| 20 | 85·6 | 86·6 | 87·7 | 88·7 |

| | 995 | 995 | 995 | 995 |

| +------+------+------+------+

| 21 | 85·3 | 86·4 | 87·4 | 88·4 |

| | 994 | 994 | 994 | 994 |

| +------+------+------+------+

| 22 | 85 | 86·1 | 87·1 | 88·2 |

| | 993 | 993 | 993 | 993 |

| +------+------+------+------+

| 23 | 84·8 | 85·8 | 86·8 | 87·9 |

| | 992 | 992 | 992 | 992 |

| +------+------+------+------+

| 24 | 84·5 | 85·5 | 86·5 | 87·6 |

| | 991 | 991 | 991 | 991 |

| +------+------+------+------+

| 25 | 84·2 | 85·2 | 86·3 | 87·4 |

| | 990 | 990 | 990 | 990 |

+-------+------+------+------+------+

I consider the preceding table, which I have extracted from the longer

tables of M. Gay Lussac, as an important addition to the resources of

British dealers and manufacturing chemists. With the aid of his little

instrument, which may be got for a trifle from its ingenious maker, M.

Collardeau, Rue Faubourg St. Martin, at Paris, or constructed by one of

the London hydrometer artists, the per centage of real alcohol, and the

real value of any spirituous liquor, may be determined to sufficient

nicety for most purposes, in a far easier manner than by any instruments

now used in this country. It has been adopted by the Swedish government,

with M. Gay Lussac’s tables.

M. Gay Lussac’s table gives, by inspection, the true bulk of the spirits

as corrected for temperature; that is, their volume, if of the normal

temperature of 15° Cent. (59° Fahr.). Now this is important information;

for, if a person buys 1000 gallons of spirits in hot weather, and pays

for them exactly according to their strength corrected for temperature,

he will not have 1000 gallons when the weather is in its mean state. He

may lose, in this way, several gallons without being aware of it from

his hydrometer.

Sometimes, after moist autumns, when damaged grain abounds, the alcohol

distilled from its fermented wash contains a peculiar volatile body.

When we apply our nose to this species of spirits in its hot state, the

volatile substance dissolved in it irritates the eyes and nostrils: it

has very nearly the same smell as an alcoholic solution of cyanogen, as

any chemist may discover by standing near the discharge pipe of the

refrigeratory worm of a raw-grain whisky still. Such spirits intoxicate

more strongly than pure spirits of the same strength, and excite, in

many persons, even temporary frenzy. It is a volatile fatty matter, of a

very fetid odour, when obtained by itself, as I have procured it in cold

weather at some of the great distilleries in Scotland. It does not

combine with bases. At the end of a few months, it spontaneously

decomposes in the spirits, and leaves them in a less nauseous and

noxious state. By largely diluting the spirits with water, and

distilling at a moderate temperature, the greater part of this oil may

be separated. Part of it comes over with the strongest alcohol, and part

with the latter runnings, which are called by the distillers strong and

weak feints. The intermediate portion is purer spirit. The feints are

always more or less opalescent, or become so on dilution with water, and

then throw up an oily pellicle upon their surface. The charcoals of

light wood, such as pine or willow, well calcined, and infused in

sufficient quantity with the spirits prior to rectification, will

deprive them of the greater part of that oily contamination. Animal

charcoal, well calcined, has also been found useful; but it must be

macerated for some time with the empyreumatic spirits, before

distillation. Another mode of separating that offensive oil is, to

agitate the impure spirits with a quantity of a fat oil, such as olive

oil, or oil of almonds, to decant off the oil, and re-distil the spirits

with a little water.

Some foreign chemists direct empyreumatic or rank spirits, to be

rectified with the addition of chloride of lime. I have tried this

method in every way, and on a considerable scale, but never found the

spirits to be improved by it. They were rather deteriorated. See

_Brandy_, _Distillation_, _Fermentation_, _Gin_, _Rum_, _Whisky_.

Anhydrous or absolute alcohol, when swallowed, acts as a mortal poison,

not only by its peculiar stimulus on the nervous system, but by its

abstracting the aqueous particles from the soft tissue of the stomach,

with which it comes in contact, so as to destroy its organisation.

Alcohol of 0·812 consists, by experiments, of 3 atoms of carbon, 6 of

hydrogen, and 2 of oxygen; absolute alcohol consists, probably, of 2 of

carbon, 3 of hydrogen, and 1 of oxygen.

ALE. The fermented infusion of pale malted barley, usually combined with

infusion of hops. See BEER.

ALEMBIC, a STILL; which see.

ALEMBROTH, salt of. The salt of wisdom, of the alchemists; a compound of

bichloride of mercury and sal ammoniac, from which the old white

precipitate of mercury is made.

ALGAROTH, powder of. A compound of oxide and chloride of antimony, being

a precipitate obtained by pouring water into the acidulous chloride of

that metal.

ALIZARINE. See MADDER.

ALKALI. A class of chemical bodies, distinguished chiefly by their

solubility in water, and their power of neutralising acids, so as to

form saline compounds. The alkalis of manufacturing importance are,

ammonia, potash, soda, and quinia. These alkalis change the purple

colour of red cabbage and radishes to a green, the reddened tincture of

litmus to a purple, and the colour of turmeric and many other yellow

dyes to a brown. Even when combined with carbonic acid, the first three

alkalis exercise this discolouring power, which the alkaline earths,

lime and barytes, do not. The same three alkalis have an acrid, and

somewhat urinous taste; the first two are energetic solvents of animal

matter; and the three combine with oils, so as to form soaps. They unite

with water in every proportion, and also with alcohol; and the first

three combine with water after being carbonated.

ALKALIMETER. An instrument for measuring the alkaline force or purity of

any of the alkalis of commerce. It is founded on the principle, that the

quantity of real alkali present in any sample, is proportional to the

quantity of acid which a given weight of it can neutralize. See the

individual alkalis, POTASH, and SODA.

ALKANA, is the name of the root and leaves of _Lausania inermis_, which

have been long employed in the East, to dye the nails, teeth, hair,

garments, &c. The leaves, ground and mixed with a little limewater,

serve for dyeing the tails of horses in Persia and Turkey.

ALKANET, the root of. (_Anchusa tinctoria._) A species of bugloss,

cultivated chiefly in the neighbourhood of Montpellier. It affords a

fine red colour to alcohol and oils; but a dirty red to water. Its

principal use is for colouring ointments, cheeses, and _pommades_. The

spirituous tincture gives to white marble a beautiful deep stain.

ALLIGATION. An arithmetical formula, useful, on many occasions, for

ascertaining the proportion of constituents in a mixture, when they have

undergone no change of volume by chemical action. When alcoholic liquors

are mixed with water, there is a condensation of bulk, which renders

that arithmetical rule inapplicable. The same thing holds, in some

measure, in the union of metals by fusion. See ALLOY.

ALLOY. (_Alliage_, Fr.; _Legirung_, Germ.) This term formerly signified

a compound of gold and silver, with some metal of inferior value, but it

now means any compound of any two or more metals whatever. Thus, bronze

is an alloy of copper and tin; brass, an alloy of copper and zinc; and

type metal, an alloy of lead and antimony. All the alloys possess

metallic lustre, even when cut or broken to pieces; they are opaque; are

excellent conductors of heat and electricity; are frequently susceptible

of crystallising; are more or less ductile, malleable, elastic, and

sonorous. An alloy which consists of metals differently fusible is

usually malleable in the cold, and brittle when hot, as is exemplified

with brass and gong metal.

Many alloys consist of definite or equivalent proportions of the simple

component metals, though some alloys seem to form in any proportion,

like combinations of salt or sugar with water. It is probable that

peculiar properties belong to the equivalent or atomic ratio, as is

exemplified in the superior quality of brass made in that proportion.

One metal does not alloy indifferently with every other metal, but it is

governed in this respect by peculiar affinities; thus, silver will

hardly unite with iron, but it combines readily with gold, copper, and

lead. In comparing the alloys with their constituent metals, the

following differences may be noted; in general, the ductility of the

alloy is less than that of the separate metals, and sometimes in a very

remarkable degree; on the contrary, the alloy is usually harder than the

mean hardness of its constituents. The mercurial alloys or amalgams are,

perhaps, exceptions to this rule.

The specific gravity is rarely the mean between that of each of its

constituents, but is sometimes greater and sometimes less, indicating,

in the former case, an approximation, and in the latter, a recedure, of

the particles from each other in the act of their union. The following

tables of binary alloys exhibit this circumstance in experimental

detail:--

Alloys having a density Alloys having a density

greater than the mean of less than the mean of

their constituents. their constituents.

Gold and zinc Gold and silver

Gold and tin Gold and iron

Gold and bismuth Gold and lead

Gold and antimony Gold and copper

Gold and cobalt Gold and iridium

Silver and zinc Gold and nickel

Silver and lead Silver and copper

Silver and tin Silver and lead

Silver and bismuth Iron and bismuth

Silver and antimony Iron and antimony

Copper and zinc Iron and lead

Copper and tin Tin and lead

Copper and palladium Tin and palladium

Copper and bismuth Tin and antimony

Lead and antimony Nickel and arsenic

Platinum and molybdenum Zinc and antimony.

Palladium and bismuth.

It would be hardly possible to infer the melting point of an alloy from

that of each of its constituent metals; but, in general, the fusibility

is increased by mutual affinity in their state of combination. Of this,

a remarkable instance is afforded in the fusible metal consisting of 8

parts of bismuth, 5 of lead, and 3 of tin, which melts at the heat of

boiling water or 212° Fahr., though the melting point deduced from the

mean of its components should be 514°. This alloy may be rendered still

more fusible by adding a very little mercury to it, when it forms an

excellent material for certain anatomical injections, and for filling

the hollows of carious teeth. Nor do the colours of alloys depend, in

any considerable degree, upon those of the separate metals; thus, the

colour of copper, instead of being rendered paler by a large addition of

zinc, is thereby converted into the rich-looking pinchbeck metal.

By means of alloys, we multiply, as it were, the numbers of useful

metals, and sometimes give usefulness to such as are separately of

little value. Since these compounds can be formed only by fusion, and

since many metals are apt to oxidise readily at their melting

temperature, proper precautions must be taken in making alloys to

prevent this occurrence, which is incompatible with their formation.

Thus, in combining tin and lead, rosin or grease is usually put on the

surface of the melting metals, the carbon produced by the decomposition

of which protects them, in most cases, sufficiently from oxidisement.

When we wish to combine tin with iron, as in the tinning of cast-iron

tea kettles, we rub sal ammoniac upon the surfaces of the hot metals in

contact with each other, and thus exclude the atmospheric oxygen by

means of its fumes. When there is a notable difference in the specific

gravities of the metals which we wish to combine, we often find great

difficulties in obtaining homogeneous alloys; for each metal may tend to

assume the level due to its density, as is remarkably exemplified in

alloys of gold and silver made without adequate stirring of the melting

metals. If the mass be large, and slow of cooling after it is cast in an

upright cylindrical form, the metals sometimes separate, to a certain

degree, in the order of their densities. Thus, in casting large bells

and cannons with copper alloys, the bottom of the casting is apt to

contain too much copper and the top too much tin, unless very dexterous

manipulation in mixing the fused materials have been employed

immediately before the instant of pouring out the melted mass. When such

inequalities are observed, the objects are broken and re-melted, after

which they form a much more homogeneous alloy. This artifice of a double

melting is often had recourse to, and especially in casting the alloys

for the specula of telescopes.

When we wish to alloy three or more metals, we often experience

difficulties, either because one of the metals is more oxidable, or

denser, or more fusible, than the others, or because there is no direct

affinity between two of the metals. In the latter predicament, we shall

succeed better by combining the three metals, first in pairs, for

example, and then melting the two pairs together. Thus, it is difficult

to unite iron with bronze directly; but if, instead of iron, we use tin

plate, we shall immediately succeed, and the bronze, in this manner,

acquires valuable qualities from the iron. Thus, also, to render brass

better adapted for certain purposes, a small quantity of lead ought to

be added to it, but this cannot be done directly with advantage: it is

better to melt the lead first along with the zinc, and then to add this

alloy to the melting copper, or the copper to that alloy, and fuse them

together.

We have said that the difference of fusibility was often an obstacle to

metallic combination; but this circumstance may also be turned to

advantage in decomposing certain alloys by the process called

_eliquation_. By this means silver may be separated from copper, if a

considerable quantity of lead be first alloyed with the said copper;

this alloy is next exposed to a heat just sufficient to melt the lead,

which then sweats out, so to speak, from the pores of the copper, and

carries along with it the greater part of the silver, for which it has a

strong affinity. The lead and the silver are afterwards separated from

each other, in virtue of their very different oxidability, by the action

of heat and air.

One of the alloys most useful to the arts is brass; it is more ductile

and less easily oxidised than even its copper constituent,

notwithstanding the opposite nature of the zinc. This alloy may exist in

many different proportions, under which it has different names, as

tombac, similor, pinchbeck, &c. Copper and tin form, also, a compound of

remarkable utility, known under the names of hard brass, for the bushes,

steps, and bearings of the axles, arbours, and spindles in machinery;

and of bronze, bell-metal, &c. Gold and silver, in their pure state, are

too soft and flexible to form either vessels or coins of sufficient

strength and durability; but when alloyed with a little copper, they

acquire the requisite hardness and stiffness for these and other

purposes.

When we have occasion to unite several pieces of the same or of

different metals, we employ the process called _soldering_, which

consists in fixing together the surfaces by means of an interposed

alloy, which must be necessarily more fusible than the metal or metals

to be joined. That alloy must also consist of metals which possess a

strong affinity for the substances to be soldered together. Hence each

metal would seem to require a particular kind of solder, which is, to a

certain extent, true. Thus, the solder for gold trinkets and plate is an

alloy of gold and silver, or gold and copper; that of silver trinkets,

is an alloy of silver and copper; that of copper is either fine tin, for

pieces that must not be exposed to the fire, or a brassy alloy called

hard solder, of which the zinc forms a considerable proportion. The

solder of lead and tinplate is an alloy of lead and tin, and that of tin

is the same alloy with a little bismuth. Tinning, gilding, and silvering

may also be reckoned a species of alloys, since the tin, gold, and

silver are superficially united in these cases to other metals.

Metallic alloys possess usually more tenacity than could be inferred

from their constituents; thus, an alloy of twelve parts of lead with one

of zinc has a tenacity double that of zinc. Metallic alloys are much

more easily oxidised than the separate metals, a phenomenon which may be

ascribed to the increase of affinity for oxygen which results from the

tendency of the one of the oxides to combine with the other. An alloy of

tin and lead heated to redness takes fire, and continues to burn for

some time like a piece of bad turf.

Every alloy is, in reference to the arts and manufactures, a new metal,

on account of its chemical and physical properties. A vast field here

remains to be explored. Not above sixty alloys have been studied by the

chemists out of many hundred which may be made; and of these very few

have yet been practically employed. Very slight modifications often

constitute very valuable improvements upon metallic bodies. Thus, the

brass most esteemed by turners at the lathe contains from two to three

per cent. of lead; but such brass does not work well under the hammer;

and, reciprocally, the brass which is best under the hammer is too tough

for turning.

That metallic alloys tend to be formed in definite proportions of their

constituents is clear from the circumstance that the native gold of the

auriferous sands is an alloy with silver, in the ratios of 1 atom of

silver united to 4, 5, 6, 12 atoms of gold, but never with a fractional

part of an atom. Also, in making an amalgam of 1 part of silver with 12

or 15 of mercury, and afterwards squeezing the mixture through chamois

leather, the amalgam separates into 2 parts: one, containing a small

proportion of silver and much mercury, passes through the skin; and the

other, formed of 1 of silver and 8 of mercury, is a compound in definite

proportions, which crystallises readily, and remains in the knot of the

bag. An analogous separation takes place in the tinning of mirrors; for

on loading them with the weights, a liquid amalgam of tin is squeezed

out, while another amalgam remains in a solid form composed of tin and

mercury in uniform atomic proportions. But, as alloys are generally

soluble, so to speak, in each other, this definiteness of combination is

masked and disappears in most cases.

M. Chaudet has made some experiments on the means of detecting the

metals of alloys by the cupelling furnace, and they promise useful

applications. The testing depends upon the appearances exhibited by the

metals and their alloys when heated on a cupel. Pure tin, when heated

this way, fuses, becomes of a greyish black colour, fumes a little,

exhibits incandescent points on its surface, and leaves an oxide, which,

when withdrawn from the fire, is at first lemon-yellow, but when cold,

white. Antimony melts, preserves its brilliancy, fumes, and leaves the

vessel coloured lemon-yellow when hot, but colourless when cold, except

a few spots of a rose tint. Zinc burns brilliantly, forming a cone of

oxide; and the oxide, much increased in volume, is, when hot, greenish,

but when cold, perfectly white. Bismuth fumes, becomes covered with a

coat of melted oxide, part of which sublimes, and the rest enters the

pores of the cupel; when cold, the cupel is of a fine yellow colour,

with spots of a greenish hue. Lead resembles bismuth very much; the cold

cupel is of a lemon-yellow colour. Copper melts, and becomes covered

with a coat of black oxide; sometimes spots of a rose tint remain on the

cupel.

Alloys.--Tin 75, antimony 25, melt, become covered with a coat of black

oxide, have very few incandescent points; when cold, the oxide is nearly

black, in consequence of the action of the antimony: a 1/400 part of

antimony may be ascertained in this way in the alloy. An alloy of

antimony, containing tin, leaves oxide of tin in the cupel: a 1/100 part

of tin may be detected in this way. An alloy of tin and zinc gives an

oxide which, whilst hot, is of a green tint, and resembles philosophic

wool in appearance. An alloy containing 99 tin, 1 zinc, did not present

the incandescent points of pure tin, and gave an oxide of greenish tint

when cold. Tin 95, bismuth 5 parts, gave an oxide of a grey colour. Tin

and lead give an oxide of a rusty brown colour. An alloy of lead and

tin, containing only 1 per cent. of the latter metal, when heated, does

not expose a clean surface, like lead, but is covered at times with

oxide of tin. Tin 75, and copper 25, did not melt, gave a black oxide:

if the heat be much elevated, the under part of the oxide is white, and

is oxide of tin; the upper is black, and comes from the copper. The

cupel becomes of a rose colour. If the tin be impure from iron, the

oxide produced by it is marked with spots of a rust colour.

The degree of affinity between metals may be in some measure estimated

by the greater or less facility with which, when of different degrees of

fusibility or volatility, they unite, or with which they can, after

union, be separated by heat. The greater or less tendency to separate

into differently proportioned alloys, by long-continued fusion, may also

give some information upon this subject. Mr. Hatchett remarked, in his

elaborate researches on metallic alloys, that gold made standard with

the usual precautions, by silver, copper, lead, antimony, &c., and then

cast, after long fusion, into vertical bars, was by no means an uniform

compound; but that the top of the bar, corresponding to the metal at the

bottom of the crucible, contained the larger proportion of gold. Hence,

for a more thorough combination, two red-hot crucibles should be

employed, and the liquefied metals should be alternately poured from the

one into the other. To prevent unnecessary oxidisement from the air, the

crucibles should contain, besides the metal, a mixture of common salt

and pounded charcoal. The metallic alloy should also be occasionally

stirred up with a rod of pottery ware.

The most direct evidence of a chemical change having been effected in

alloys is, when the compound melts at a lower temperature than the mean

of its ingredients. Iron, which is nearly infusible, acquires almost the

fusibility of gold when alloyed with this precious metal. The analogy is

here strong with the increase of solubility which salts acquire by

mixture, as is exemplified in the difficulty of crystallising residuums

of saline solutions, or mother waters, as they are called.

In common cases the specific gravity affords a good criterion whereby to

judge of the proportion of two metals in an alloy. But a very fallacious

rule has been given in some respectable works for computing the specific

gravity that should result from the alloying of given quantities of two

metals of known densities, supposing no chemical condensation or

expansion of volume to take place. Thus, it has been taught, that if

gold and copper be united in equal weights, the computed specific

gravity is merely the arithmetical mean between the numbers denoting the

two specific gravities. Whereas, the specific gravity of any alloy must

be computed by dividing the sum of the two weights by the sum of the two

volumes, compared, for conveniency sake, to water reckoned unity. Or, in

another form, the rule may be stated thus:--Multiply the sum of the

weights into the products of the two specific-gravity numbers for a

numerator; and multiply each specific gravity-number into the weight of

the other body, and add the two products together for a denominator. The

quotient obtained by dividing the said numerator by the denominator, is

the truly computed mean specific gravity of the alloy. On comparing with

that density, the density found by experiment, we shall see whether

expansion or condensation of volume has attended the metallic

combination. Gold having a specific gravity of 19·36, and copper of

8·87, when they are alloyed in equal weights, give, by the fallacious

rule of the arithmetical mean of the densities (19·36 + 8·87)/2 = 14·11;

whereas the rightly computed mean density is only 12·16. It is evident

that, on comparing the first result with experiment, we should be led to

infer that there had been a prodigious condensation of volume, though

expansion has actually taken place. Let W, w be the two weights; P, p

the two specific gravities, then M, the mean specific gravity, is given

by the formula--

(W + w) P p (P - p)²

M = ----------- ∴ 2Δ = - -------- =

P w + p W P + p

twice the error of the arithmetical mean; which is therefore always in

excess.

ALMOND. (_Amande_, Fr.; _Mandel_, Germ.) There are two kinds of almond

which do not differ in chemical composition, only that the bitter, by

some mysterious reaction of its constituents, generates in the act of

distillation a quantity of a volatile oil, which contains hydrocyanic

acid. Vogel obtained from bitter almonds 8·5 per cent. of husks. After

pounding the kernels, and heating them to coagulate the albumen, he

procured, by expression, 28 parts of an unctuous oil, which did not

contain the smallest particle of hydrocyanic acid. The whole of the oil

could not be extracted in this way. The expressed mass, treated with

boiling water, afforded sugar and gum, and, in consequence of the heat,

some of that acid. The sugar constitutes 6·5 per cent. and the gum 3.

The vegetable albumen extracted, by means of caustic potash, amounted to

30 parts: the vegetable fibre to only 5. The poisonous aromatic oil,

according to Robiquet and Boutron-Charlard, does not exist ready-formed

in the bitter almond, but seems to be produced under the influence of

ebullition with water. These chemists have shown that bitter almonds

deprived of their unctuous oil by the press, when treated first by

alcohol, and then by water, afford to neither of these liquids any

volatile oil. But alcohol dissolves out a peculiar white crystalline

body, without smell, of a sweetish taste at first, and afterwards

bitter, to which they gave the name of _amygdaline_. This substance does

not seem convertible into volatile oil.

Sweet almonds by the analysis of Boullay, consist of 54 parts of the

bland almond oil, 6 of uncrystallisable sugar, 3 of gum, 24 of vegetable

albumen, 24 of woody fibre, 5 of husks, 3·5 of water, 0·5 of acetic

acid, including loss. We thus see that sweet almonds contain nearly

twice as much oil as bitter almonds do.

ALMOND OIL. A bland fixed oil, obtained usually from bitter almonds by

the action of a hydraulic press, either in the cold, or aided by hot

iron plates. See OIL.

ALOE. A series of trials has been made within a few years at Paris to

ascertain the comparative strength of cables made of hemp and of the

aloe from Algiers; and they are said to have all turned to the advantage

of the aloe. Of cables of equal size, that made of aloe raised a weight

of 2,000 kilogrammes (2 tons nearly); that made of hemp, a weight of

only 400 kilogrammes. At the exposition of objects of national industry,

two years ago, in Brussels, I saw aloe cordage placarded, as being far

preferable to hempen. See ROPE.

ALUDEL. A pear-shaped vessel open at either end, of which a series are

joined for distilling mercury in Spain. See MERCURY.

ALUM. (_Alun_, Fr.; _Alaum_, Germ.) A saline body, consisting of the

earth of clay, called alumina by the chemists, combined with sulphuric

acid and potash, or sulphuric acid and ammonia, into a triple compound.

It occurs in the crystallised form of octahedrons, has an acerb subacid

taste, and reddens the blue colour of litmus or red cabbage.

Alum works existed many centuries ago at Roccha, formerly called Edessa,

in Syria, whence the ancient name of Roch alum given to this salt. It

was afterwards made at Foya Nova, near Smyrna, and in the neighbourhood

of Constantinople. The Genoese, and other trading people of Italy,

imported alum from these places into western Europe, for the use of the

dyers of red cloth. About the middle of the fifteenth century, alum

began to be manufactured at La Tolfa, Viterbo, and Volaterra, in Italy;

after which time the importation of oriental alum was prohibited by the

pope, as detrimental to the interests of his dominions. The manufacture

of this salt was extended to Germany at the beginning of the sixteenth

century, and to England at a somewhat later period, by Sir Thomas

Chaloner, in the reign of Elizabeth. In its pure state, it does not seem

to have been known to the ancients; for Pliny, in speaking of something

like plumose alum, says, that it struck a black colour with pomegranate

juice, which shows that the green vitriol was not separated from it. The

_stypteria_ of Dioscorides, and the _alumen_ of Pliny, comprehended,

apparently, a variety of saline substances, of which sulphate of iron,

as well as alumina, was probably a constituent part. Pliny, indeed,

says, that a substance called in Greek Ὑγρα, or watery, probably from

its very soluble nature, which was milk-white, was used for dyeing wool

of bright colours. This may have been the mountain butter of the German

mineralogists, which is a native sulphate of alumina, of a soft texture,

waxy lustre, and unctuous to the touch.

The only alum manufactories now worked in Great Britain, are those of

Whitby, in England, and of Hurlett and Campsie, near Glasgow, in

Scotland; and these derive the acid and earthy constituents of the salt

from a mineral called alum slate. This mineral has a bluish or

greenish-black colour, emits sulphurous fumes when heated, and acquires

thereby an aluminous taste. The alum manufactured in Great Britain

contains potash as its alkaline constituent; that made in France

contains, commonly, ammonia, either alone, or with variable quantities

of potash. Alum may in general be examined by water of ammonia, which

separates from its watery solutions its earthy basis, in the form of a

light flocculent precipitate. If the solution be dilute, this

precipitate will float long as an opalescent cloud.

If we dissolve alum in 20 parts of water, and drop this solution slowly

into water or caustic ammonia till this be nearly, but not entirely,

saturated, a bulky white precipitate will fall down, which, when

properly washed with water, is pure aluminous earth or clay, and dried

forms 10·82 per cent. of the weight of the alum. If this earth, while

still moist, be dissolved in dilute sulphuric acid, it will constitute,

when as neutral as possible, the sulphate of alumina, which requires

only two parts of cold water for its solution. If we now decompose this

solution, by pouring into it water of ammonia, there appears an

insoluble white powder, which is subsulphate of alumina, or basic alum;

and contains three times as much earth as exists in the neutral

sulphate. If, however, we pour into the solution of the neutral sulphate

of alumina a solution of sulphate of potash, a white powder will fall if

the solutions be concentrated, which is true _alum_; but if the

solutions be dilute, by evaporating their mixture, and cooling it,

crystals of alum will be obtained.

When newly precipitated alumina is boiled in a solution of alum, a

portion of the earth enters into combination with the salt, constituting

an insoluble compound, which falls in the form of a white powder. The

same combination takes place, if we decompose a boiling hot solution of

alum with a solution of potash, till the mixture appears nearly neutral

by litmus paper. This insoluble or basic alum exists native in the

alum-stone of Tolfa, near Civita Vecchia, and it consists in 100 parts

of 19·72 parts of sulphate of potash, 61·99 basic sulphate of alumina,

and 18·29 water. When this mineral is treated with a due quantity of

sulphuric acid, it dissolves, and is converted into the crystallisable

alum of commerce.

These experimental facts develope the principles of the manufacture of

alum, which is prosecuted under various modifications, for its important

uses in the arts. Alum seldom occurs ready-formed in nature;

occasionally, as an efflorescence on stones, and in certain mineral

waters in the East Indies. The alum of European commerce is fabricated

artificially, either from the alum schists or stones, or from clay. The

mode of manufacture differs according to the nature of these earthy

compounds. Some of them, such as the alum stone, contain all the

elements of the salt, but mixed with other matters, from which it must

be freed. The schists contain only the elements of two of the

constituents, namely, clay and sulphur, which are convertible into

sulphate of alumina, and this may be then made into alum by adding the

alkaline ingredient. To this class belong the alum slates, and other

analogous schists, containing brown coal.

1. _Manufacture of Alum from the Alum Stone._--The alum-stone is a rare

mineral, being found in moderate quantity at Tolfa, and in larger in

Hungary, at Bereghszasz, and Muszag, where it forms entire beds in a

hard substance, partly characterised by numerous cavities, containing

drusy crystallisations of alum-stone or basic alum. The larger lumps

contain more or fewer flints disseminated through them, and are,

according to their quality, either picked out to make alum, or are

thrown away. The sorted pieces are roasted or calcined, by which

operation apparently the hydrate of alumina, associated with the

sulphate of alumina, loses its water, and, as burnt clay, loses its

affinity for alum. It becomes, therefore, free; and during the

subsequent exposure to the weather the stone gets disintegrated, and the

alum becomes soluble in water.

The calcination is performed in common lime-kilns in the ordinary way.

In the regulation of the fire it is requisite, here, as with gypsum, to

prevent any fusion or running together of the stones, or even any

disengagement of sulphuric or sulphurous acids, which would cause a

corresponding defalcation in the product of alum. For this reason the

contact of the ignited stones with carbonaceous matter ought to be

avoided.

The calcined alum-stones, piled in heaps from 2 to 3 feet high, are to

be exposed to the weather, and meanwhile they must be continually kept

moist by sprinkling them with water. As the water combines with the alum

the stones crumble down, and fall, eventually, into a pasty mass, which

must be lixiviated with warm water, and allowed to settle in a large

cistern. The clear supernatant liquor, being drawn off, must be

evaporated, and then crystallised. A second crystallisation finishes the

process, and furnishes a marketable alum. Thus the Roman alum is made,

which is covered with a fine red film of peroxide of iron.

2. _Alum Manufacture from Alum Schist._--The greater portion of the alum

found in British commerce is made from alum-slate and analogous

minerals. This slate contains more or less iron pyrites, mixed with

coaly or bituminous matter, which is occasionally so abundant as to

render them somewhat combustible. In the strata of brown coal and

bituminous wood, where the upper layers lie immediately under clay beds,

they consist of the coaly substance rendered impure with clay and

pyrites. This triple mixture constitutes the essence of all good alum

schists, and it operates spontaneously towards the production of

sulphate of alumina. The coal serves to make the texture open, and to

allow the air and moisture to penetrate freely, and to change the

sulphur and iron present into acid and oxide. When these schists are

exposed to a high temperature in contact with air, the pyrites loses one

half of its sulphur, in the form of sublimed sulphur or sulphurous acid,

and becomes a black sulphuret of iron, which speedily attracts oxygen,

and changes to sulphate of iron, or green vitriol. The brown coal

schists contain, commonly, some green vitriol crystals spontaneously

formed in them. The sulphate of iron transfers its acid to the clay,

progressively, as the iron, by the action of the air with a little

elevation of temperature, becomes peroxidised; whereby sulphate of

alumina is produced. A portion of the green vitriol remains, however,

undecomposed, and so much the more as there may happen to be less of

other salifiable bases present in the clay slate. Should a little

magnesia or lime be present, the vitriol gets more completely

decomposed, and a portion of Epsom salt and gypsum is produced.

The manufacture of alum from alum schists may be distributed under the

six following heads:--1. The preparation of the alum slate. 2. The

lixiviation of the slate. 3. The evaporation of the lixivium. 4. The

addition of the saline ingredients, or the precipitation of the alum. 5.

The washing of the aluminous salts; and 6. The crystallisation.

1. _Preparation of the Alum Slate._--Some alum slates are of such a

nature that, being piled in heaps in the open air, and moistened from

time to time, they get spontaneously hot, and by degrees fall into a

pulverulent mass, ready to be lixiviated. The greater part, however,

require the process of ustulation, from which they derive many

advantages. The cohesion of the dense slates is thereby so much impaired

that their decomposition becomes more rapid; the decomposition of the

pyrites is quickened by the expulsion of a portion of the sulphur; and

the ready-formed green vitriol is partly decomposed by the heat, with a

transference of its sulphuric acid to the clay, and the production of

sulphate of alumina.

Such alum-slates as contain too little bitumen or coal for the roasting

process must be interstratified with layers of small coal or brushwood

over an extensive surface. At Whitby the alum rock, broken into small

pieces, is laid upon a horizontal bed of fuel, composed of brushwood;

but at Hurlett small coal is chiefly used for the lower bed. When about

four feet of the rock is piled on, fire is set to the bottom in various

parts; and whenever the mass is fairly kindled, more rock is placed over

the top. At Whitby this piling process is continued till the calcining

heap is raised to the height of 90 or 100 feet. The horizontal area is

also augmented at the same time till it forms a great bed nearly 200

feet square, having therefore about 100,000 yards of solid measurement.

The rapidity of the combustion is tempered by plastering up the crevices

with small schist moistened. When such an immense mass is inflamed, the

heat is sure to rise too high, and an immense waste of sulphur and

sulphuric acid must ensue. This evil has been noticed at the Whitby

works. At Hurlett the height to which the heap is piled is only a few

feet, while the horizontal area is expanded; which is a much more

judicious arrangement. At Whitby 130 tons of calcined schist produce on

an average 1 ton of alum. In this humid climate it would be advisable to

pile up on the top of the horizontal strata of brushwood or coal, and

schist, a pyramidal mass of schist, which having its surface plastered

smooth, with only a few air-holes, will protect the mass from the rains,

and at the same time prevent the combustion from becoming too vehement.

Should heavy rains supervene, a gutter must be scooped out round the

pile for receiving the aluminous lixivium, and conducting it into the

reservoir.

It may be observed, that certain alum schists contain abundance of

combustible matter, to keep up a suitable calcining heat after the fire

is once kindled; and therefore nothing is needed but the first layer of

brushwood, which, in this case, may be laid over the first bed of the

bituminous schist.

A continual, but very slow, heat, with a smothered fire, is most

beneficial for the ustulation of alum slate. When the fire is too brisk,

the sulphuret of iron may run with the earthy matters into a species of

slag, or the sulphur will be dissipated in vapour, by both of which

accidents the product of alum will be impaired. Those bituminous alum

schists which have been used as fuel under steam boilers have suffered

such a violent combustion that their ashes yield almost no alum. Even

the best regulated calcining piles are apt to burn too briskly in high

winds, and should have their draught-holes carefully stopped under such

circumstances. It may be laid down as a general rule, that the slower

the combustion the richer the roasted ore will be in sulphate of

alumina. When the calcination is complete, the heap diminishes to one

half its original bulk; it is covered with a light reddish ash, and is

open and porous in the interior, so that the air can circulate freely

throughout the mass. To favour this access of air, the masses should not

be too lofty; and in dry weather a little water should be occasionally

sprinkled on them, which, by dissolving away some of the saline matter,

will make the interior more open to the atmosphere.

When the calcined mineral becomes thoroughly cold, we may proceed to the

lixiviation. But as, from the first construction of the piles or beds

till their complete calcination, many weeks, or even months, may elapse,

care ought to be taken to provide a sufficient number or extent of them,

so as to have an adequate supply of material for carrying on the

lixiviating and crystallising processes during the course of the year,

or at least during the severity of the winter season, when the

calcination may be suspended, and the lixiviation becomes

unsatisfactory. The beds are known to be sufficiently decomposed by the

efflorescence of the salt which appears upon the stones, from the strong

aluminous taste of the ashes, and from the appropriate chemical test of

lixiviating an aliquot average portion of the mass, and seeing how much

alum it will yield to solution of muriate or sulphate of potash.

A Dictionary of Arts, Manufactures and Mines containing a clear exposition of their principles and practice · 第 6 / 421 题

The following specimen table has been given by the committee:--