ounces of chlorate soda in 1,000 ounces of water.
II.—Dip the article in a solution of ferrocyanide of potassium very
strongly acidulated with hydrochloric acid.
III.—Stir the article about constantly in a solution of liver of
sulphur in 50 times its weight of water.
«Fusion Point of Metals.»—The point of fusion of common metals is as
follows: Antimony, 808° F.; aluminum, 1,160° F.; bismuth, 517° F.;
copper, 1,931° F.; gold, 1,913° F.; iron, 2,912° F.; lead, 850° F.;
nickel, 2,642° F.; platinum, 3,225° F.; silver, 1,750° F.; tin,
551° F.; zinc, 812° F. Mercury, which is normally fluid, congeals at
38° below zero, F., this being its point of fusion.
«To Produce Fine Leaves of Metal.»—The metal plate is laid between
parchment leaves and beaten out with hammers. Although films obtained
in this manner reach a high degree of fineness, yet the mechanical
production has its limit. If very fine films are desired the
galvano-plastic precipitation is employed in the following manner:
A thin sheet of polished copper is entered in the bath and connected
with the {474} electric conduit. The current precipitates gold on it.
In order to loosen it, the gilt copper plate is placed in a solution of
ferric chloride, which dissolves the copper and leaves the gold behind.
In this manner gold leaf can be hammered out to almost incredible
thinness.
«METAL FOIL.»
Tin foil is the most common foil used, being a combination of tin,
lead, and copper, sometimes with properties of other metals.
I II III
Per cent Per cent Per cent
Tin 97.60 98.47 96.21
Copper 2.11 0.38 0.95
Lead 0.04 0.84 2.41
Iron 0.11 0.12 0.09
Nickel — — 0.30
I is a mirror foil; III is a tin foil.
Tin Foils for Capsules.—
I II
Per cent Per cent
Tin 20 22
Lead 80 77
Copper — 1
Tin Foils for Wrapping Cheese, etc.—
I II III
Per cent Per cent Per cent
Tin 97 90 92
Lead 2.5 7.8 7
Copper 0.5 0.2 1
Tin Foils, for Fine Wrapping, I and II; for Tea Boxes, III.—
I II III
Per cent Per cent Per cent
Tin 60 65 40
Lead 40 35 58.5
Copper — — 1.5
Imitation Gold Foils.—
Deep gold Pure gold Pale gold
Per cent Per cent Per cent
Copper 84.5 78 76
Zinc 15.5 22 14
Deep gold Deep gold Gold
Per cent Per cent Per cent
Copper 91 86 83
Zinc 9 14 17
dark pale
reddish yellow yellow
Imitation Silver Foil.—Alloy of tin and zinc: harder than tin and
softer than zinc: Zinc, 1 part; tin, 11 parts.
To Attach Gold Leaf Permanently.—Dissolve finely cut isinglass in a
little water, with moderate heat, which must not be increased to a
boil, and add as much nitric acid as has been used of the isinglass.
The adhesive will not penetrate the cardboard or paper.
METH: See Mead.
METHEGLIN: See Mead.
METHYL SALICYLATE, TO DISTINGUISH FROM OIL OF WINTERGREEN: See
Wintergreen.
METOL DEVELOPER: See Photography.
METRIC WEIGHTS: See Weights and Measures.
MICE POISON: See Rat Poison.
MICROPHOTOGRAPHS: See Photography.
«MILK:»
See also Foods.
«Determining Cream.»—An apparatus for determining cream in milk
consists of a glass cylinder having a mark about half its height,
and a second mark a little above the first. The milk is added up to
the lower mark, and water up to the second. The amount of water thus
added is about one-fourth the volume of the milk, and causes the cream
to rise more quickly. The tube is graduated between the two marks in
percentages of cream on the undiluted milk. A vertical blue strip in
the side of the cylinder aids the reading of the meniscus.
«Formaldehyde in Milk, Detection of.»—To 10 parts of milk add 1 part of
fuchsine sulphurous acid. Allow to stand 5 minutes, then add 2 parts of
pure hydrochloric acid and shake. If formaldehyde is not present, the
mixture remains yellowish white, while if present a blue-violet color
is produced. This test will detect 1 grain of anhydrous formaldehyde in
1 quart of milk.
«Malted Milk.»—To malt milk, add the following:
Powdered malt 1 ounce
Powdered oat meal 2 ounces
Sugar of milk 4 ounces
Roasted flour 1 pound
«Milk Extracts.»—These are made from skimmed milk freed from casein,
sugar and albumen, and resemble meat extracts. The milk is slightly
acidulated with phosphoric or hydrochloric acid, and evaporated
_in vacuo_ to the {475} consistency of thick syrup. During the
crystallization of the sugar, the liquid is sterilized.
«Modification of Milk for Infants.»—For an ill child note the
percentages of milk taken; decide, if indigestion is present, which
ingredient of the milk, fat or proteid, or both, is at fault, and make
formula accordingly.
After allowing the milk to stand 8 hours, remove the top 8 ounces
from a quart jar of 4 per cent fat milk by means of a dipper, and
count this as 12 per cent fat cream. Count the lowest 8 ounces of the
quart fat-free milk. From these the following formula may be obtained,
covering fairly well the different percentages required for the
different periods of life.
_First Week._
12 per cent cream. Fat-free milk.
Fat 2.00 Cream 3 1/4 oz.
Sugar 5.00 Milk 1 1/2 oz.
Proteids 0.75 Milk sugar 2 meas.
_Second Week._
Fat 2.50 Cream 4 1/4 oz.
Sugar 6.00 Milk 1 1/4 oz.
Proteids 1.00 Milk sugar 2 1/2 meas.
_Third Week._
Fat 3.00 Cream 5 oz.
Sugar 6.00 Milk 1 oz.
Proteids 1.00 Milk sugar 2 1/2 meas.
_Four to Six Weeks._
Fat 3.50 Cream 5 3/4 oz.
Sugar 6.50 Milk 1 3/4 oz.
Proteids 1.00 Milk sugar 2 1/2 meas.
_Six to Eight Weeks._
Fat 3.50 Cream 5 3/4 oz.
Sugar 6.50 Milk 3 1/4 oz.
Proteids 1.50 Milk sugar 2 1/4 meas.
_Two to Four Months._
Fat 4.00 Cream 6 3/4 oz.
Sugar 7.00 Milk 2 1/4 oz.
Proteids 1.50 Milk sugar 2 1/2 meas.
_Four to Eight Months._
Fat 4.00 Cream 6 3/4 oz.
Sugar 7.00 Milk 4 3/4 oz.
Proteids 2.00 Milk sugar 2 1/4 meas.
_Eight to Nine Months._
Fat 4.00 Cream 6 3/4 oz.
Sugar 7.00 Milk 7 1/2 oz.
Proteids 2.50 Milk sugar 2 meas.
_Nine to Ten Months._
Fat 4.00 Cream 6 3/4 oz.
Sugar 7.00 Milk 10 1/2 oz.
Proteids 3.00 Milk sugar 1 1/2 meas.
_Ten to Twelve Months._
Fat 4.00 Cream 6 3/4 oz.
Sugar 5.00 Milk 11 3/4 oz.
Proteids 3.50 Milk sugar 1/2 meas.
_After Twelve Months._
Unmodified cow’s milk.
«Preservation of Milk» (see also Foods).—I.—Shortly after the milk
is strained add to it from 1 per cent to 2 per cent of a 12-volume
solution of hydrogen peroxide, and set it aside for 10 to 12 hours. It
thus acquires the property of keeping perfectly sweet and fresh for 3
or 4 days, and is far preferable to milk sterilized by heat. Two points
are worthy of notice in the process. The addition of oxygenated water
should be made as soon after it is taken from the cow, strained, etc.,
as possible; the peroxide appears to destroy instantly all anaërobic
microbes (such as the bacillus of green diarrhea of childhood), but
has no effect upon the bacillus of tuberculosis. This process is to be
especially recommended in the heat of summer, and at all times in the
milk of cattle known to be free of tuberculosis.
II.—Fresh milk in bottles has been treated with oxygen and carbonic
acid under pressure of some atmospheres. By this method it is said to
be possible to preserve milk fresh 50 to 60 days. The construction of
the bottle is siphon-like.
«Milk Substitute.»—Diamalt is a thick syrupy mass of pleasant, strong,
somewhat sourish odor and sweetish taste, which is offered as a
substitute for milk. The preparation has been analyzed. Its specific
gravity is 1.4826; the percentage of water fluctuates between 24 and 28
per cent; the amount of ash is 1.3 per cent. There are present: Lactic
acid, 0.718 to 1.51; nitrogenous matter, 4.68 to 5.06 per cent; and
constituents rich in nitrogen, about 68 per cent. The latter consist
principally of maltose. Dissolved in water it forms a greenish-yellow
mixture. Turbidness is caused by starch grains, yeast cells, bacteria,
and a shapeless coagulum.
MILK AS A SUBSTITUTE FOR CELLULOID, BONE, AND IVORY: See Casein.
MILK, CUCUMBER: See Cosmetics.
MILK OF SOAP: See Cleaning Preparations and Methods, under
Miscellaneous Methods.
MINARGENT: See Alloys. {476}
MINERAL WATERS: See Waters.
MINOFOR METAL: See Alloys.
MINT CORDIAL: See Wines and Liquors.
«Mirrors»
(See also Glass.)
«Mirror Silvering.»—Mirror silvering is sometimes a misnomer, inasmuch
as the coating applied to glass in the manufacture of mirrors does not
always contain silver. In formula I it is an amalgam of mercury and tin.
I.—A sheet of pure tin foil, slightly larger than the glass plate to be
silvered, is spread evenly on a perfectly plane stone table having a
raised edge, and is well cleaned from all dust and impurity. The foil
must be free from the slightest flaw or crack. The tin is next covered
uniformly to a depth of 1/8 of an inch with mercury, preference
being given by some to that containing a small proportion of tin from
a previous operation. The glass plate, freed from all dust or grease,
and repolished if necessary, is then carefully slid over the mercury.
This part of the work requires skill and experience to exclude all air
bubbles, and even the best workmen are not successful every time. If
there is a single bubble or scratch the operation must be repeated and
the tin foil is lost; not a small expense for large sizes. When this
step has been satisfactorily accomplished the remainder is easy. The
glass plate is loaded with heavy weights to press out the excess of
mercury which is collected and is used again. After 24 hours the mirror
is lifted from the table and placed on edge against a wall, where it is
left to drain well.
II.—Solution No. 1 is composed as follows: To 8 ounces of distilled
water, brought to a boil, add 12 grains of silver nitrate and 12 grains
of Rochelle salts. Let it come to a boil for 6 to 7 minutes; then cool
and filter.
Solution No. 2 is made as follows: Take 8 ounces of distilled water,
and into a small quantity poured into a tumbler put 19 grains of silver
nitrate. Stir well until dissolved. Then add several drops of 26°
ammonia until the solution becomes clear. Add 16 grains more of nitrate
of silver, stirring well until dissolved. Add balance of distilled
water and filter. The filtering must be done through a glass funnel, in
which the filter paper is placed. The solution must be stirred with a
glass rod. Keep the solutions in separate bottles marked No. 1 and No.
2.
Directions for Silvering: Clean the glass with ammonia and wipe with
a wet chamois. Then take half and half of the two solutions in a
graduating glass, stirring well with a glass rod. Pour the contents on
the middle of the glass to be silvered. It will spread over the surface
of itself if the glass is laid flat. Leave it until the solution
precipitates.
«Silvering Globes.»—The insides of globes may be silvered, it is said,
by the following methods:
I.—Take 1/3 ounce of clean lead, and melt it with an equal weight of
pure tin; then immediately add 1/2 ounce of bismuth, and carefully
skim off the dross; remove the alloy from the fire, and before it grows
cold add 5 ounces of mercury, and stir the whole well together; then
put the fluid amalgam into a clean glass, and it is fit for use. When
this amalgam is used for silvering, it should be first strained through
a linen rag; then gently pour some ounces of it into the globe intended
to be silvered; the alloy should be poured into the globe by means of
a paper or glass funnel reaching almost to the bottom of the globe, to
prevent it splashing the sides; the globe should be turned every way
very slowly, to fasten the silvering.
II.—Make an alloy of 3 ounces of lead, 2 ounces of tin, and 5 ounces of
bismuth. Put a portion of this alloy into the globe and expose it to a
gentle heat until the compound is melted; it melts at 197° F.; then by
turning the globe slowly round, an equal coating may be laid on, which,
when cold, hardens and firmly adheres.
«Resilvering Mirrors»—If mirrors coated with amalgam become damaged
they may sometimes be successfully repaired by one of the following
processes:
I.—Place the old mirror in a weak solution of nitric acid—say 5 per
cent—which immediately removes the silver. Rinse it a little, and then
clean very thoroughly with a pledget of cotton-wool and a mixture of
whiting and ammonia. Rouge will answer in place of whiting, or, as
a last extreme, finest levigated pumice, first applied to a waste
glass to crush down any possible grit. This cleaning is of the utmost
importance, as upon its thoroughness depends eventual success. Front,
back, and edges must alike be left in a state above suspicion. The
{477} plate is then again flowed with weak acid, rinsed under the tap,
then flowed back and front with distilled water, and kept immersed in a
glass-covered dish of distilled water until the solutions are ready.
The depositing vessel is the next consideration, and it should be
realized that unless most of the silver in the solution finds its way
on to the face of the mirror it were cheaper that the glass should be
sent to the professional mirror-maker. The best plan is to use a glass
dish allowing a 1/16 inch margin all round the mirror, inside. But
such a glass dish is expensive, having to be made specially, there
being no regular sizes near enough to 4 x 7 or 8 x 5 (usual mirror
sizes). If too large, a dish must perforce be used, the sides or ends
of which should be filled up with sealing wax. Four strips of glass
are temporarily bound together with 2 or 3 turns of string, so as to
form a hollow square. The side pieces are 1/8 inch longer outside,
and the end pieces 1/8 inch wider than the mirror glass. This frame
is placed in about the center of the dish, moistened with glycerine,
and the molten wax flowed outside of it to a depth of about 3/4 of an
inch or more. For economy’s sake, good “parcel wax” may be used, but
best red sealing wax is safer. This wax frame may be used repeatedly,
being cleaned prior to each silvering operation. It is the only special
appliance necessary, and half an hour is a liberal time allowance for
making it.
Use a stock solution of silver nitrate of the strength of 25 grains
to 1 ounce of distilled water: Take 2 drachms of silver nitrate stock
solution and convert it to ammonia nitrate, by adding ammonia drop
by drop until the precipitate is redissolved. Add 3 1/2 ounces of
distilled water.
In another measure take 80 drops (approximately 74 minims) of 40 per
cent formalin. Pour the solution of ammonio nitrate of silver into the
measure containing the formalin, then back into the original measure,
and finally into the dish containing the glass to be silvered. This
should be done rapidly, and the dish containing the mirror well rocked
until the silvering is complete, which may be ascertained by the
precipitation of a black, flocculent deposit, and the clearing of the
solution. The actual process of silvering takes about 2 minutes.
Cleanliness throughout is of the greatest importance. The vessels in
which the solutions are mixed should be well rinsed with a solution of
bichromate of potash and sulphuric acid, then washed out three or four
times under the tap, and finally with distilled water. For cleansing,
dip the glass for a short time in a solution of bichromate of potash,
to which a little sulphuric acid is added. The glass is afterwards well
rinsed for a minute or two under the tap, flooded with distilled water,
and dried with a clean linen cloth. A little absolute alcohol is then
rubbed on with a soft linen handkerchief, which is immediately rolled
into a pad and used for well polishing the surface. The cleaning with
alcohol is repeated to avoid risk of failure.
After the mirror has been silvered, hold it under the tap and allow
water to flow over it for about 3 minutes. Rinse it with distilled
water, and stand it up on edge on blotting paper. When it is quite dry
take a pad of very soft wash-leather, spread a small quantity of finest
opticians’ rouge on a sheet of clean glass, and well coat the pad with
rouge by polishing the sheet of glass. A minute quantity of rouge is
sufficient. Afterwards polish the mirror by gently rubbing the surface
with the pad, using a circular stroke.
It will be seen that with this process it is unnecessary to suspend the
mirror in the silvering solution, as usually recommended. The mirror is
laid in the dish, which is a distinct advantage, as the progress of the
silvering may be watched until complete. The film also is much more
robust than that obtained by the older methods.
II.—Clean the bare portion of the glass by rubbing it gently with
fine cotton, taking care to remove any trace of dust and grease. If
this cleaning be not done very carefully, defects will appear around
the place repaired. With the point of a penknife cut upon the back of
another looking glass around a portion of the silvering of the required
form, but a little larger. Upon it place a small drop of mercury; a
drop the size of a pin’s head will be sufficient for a surface equal to
the size of the nail. The mercury spreads immediately, penetrates the
amalgam to where it was cut off with the knife, and the required piece
may be now lifted and removed to the place to be repaired. This is the
most difficult part of the operation. Then press lightly the renewed
portion with cotton; it hardens almost immediately, and the glass
presents the same appearance.
«Clouding of Mouth Mirrors.»—By means of the finger, slightly
moistened, apply a film of soap of any brand or kind to the mirror;
then rub this off with a clean, dry cloth; the mirror will be as {478}
bright and clear as ever. Breathing on it will not affect its clearness
and the mirror does not suffer from the operation.
«Magic Mirrors.»—Among the many amusing and curious articles which
the amateur mechanic can turn out, metallic mirrors having concealed
designs on them, and which can be brought into view by breathing on the
polished surface, are both funny and easy to produce. To produce steel
mirrors either tough bronze or good cast mottled iron discs should be
used, and the design should be on the bottom of the cast disc, as this
is the soundest and densest part of the metal. The method of working is
different with bronze and iron, and bronze will be dealt with first.
The cast disk of bronze should be turned up level on both sides, and
the edges should be turned or shaped up, the metal being about half
an inch thick. On the side which was at the bottom in casting, a line
should be drawn to allow for working up the border or frame of the
mirror, and on the rest of the smooth surface the design should be
drawn, not having too much detail. It is best to mark the lines with
a sharp scriber, to prevent their effacement during working. When the
disk is marked out, it should be laid on a smoothly planed iron block,
and the lines punched to a depth of about 1/4 inch, a punch with
round edges being used. Then the disk should be turned down to just
below the surface of the punched-in metal, and the border or edge
formed, finishing smoothly, but without burnishing. The back can be
turned down and, with the outer edge, burnished; but the inside of the
edge and the face of the mirror should be polished with fine abrasive
powder, and finished with fine rouge. When dry, the mirror will appear
equally bright all over; but when breathed on the design will show,
again disappearing as the moisture is removed. The metal punched in
will be more dense than the rest of the surface, and will also be very
slightly raised, this being imperceptible unless the polishing has been
too long continued.
With iron mirrors a good mottled iron must be used, selecting hematite
for preference; but in any case it must be chillable metal. Preferably
it should be melted in a crucible, as this causes the least change in
the metallic content, and as the metal can be made hot and fluid, it
works well. The design must be worked out in iron of about 1/8 inch
in thickness, and must be level, as it has to touch the molten metal
in the bottom of the mold. If preferred, the design may be cast and
ground flat, but this depends largely on the design. The chill pattern
should be coated with plumbago, and in molding the disk pattern of
about 1/4 inch in thickness should be laid on a board, and on this
the design—chill—should be placed, and the mold should be rammed up
from the back in the ordinary manner. The casting should be allowed to
get cold in the mold, and should then be removed and dressed in the
usual way. It should then be ground bright all over on emery wheels of
successively finer grades, and the mirror surface should be buffed and
polished until a steely mirror surface is produced. With a good mottled
iron the chilled design will not show until the surface is breathed on
or rubbed with a greasy rag, but will then show clearly.
MIRROR ALLOYS: See Alloys.
MIRRORS, FROSTED: See Glass.
MIRROR-LETTERING: See Lettering.
MIRROR POLISHES: See Polishes.
MIRRORS, TO CLEAN: See Cleaning Preparations and Methods.
MIRRORS, TO PREVENT DIMMING OF: See Glass.
MIRROR VARNISH: See Varnishes.
MITE KILLER: See Insecticides.
MIXING STICKS FOR PAINT: See Paint.
MODELING WAX: See Wax, Modeling.
MOISTURE: See Insulation.
«MOLDS:»
See also Casting and Matrix.
«Molding Sand.»—A high grade of molding sand should be fat, i. e.,
strongly mixed with clay. Naturally the molds of this sand should
be employed only in a perfectly dry state. The fat molding sand is
prepared artificially from quartz sand (fine sprinkling sand), fat
clay, free {479} from lime and ferric oxide (red ocher). The molding
sand is fixed by breaking up the loose pieces in which it is partly
dug; next it is passed through a fine sieve and mixed up to one-third
of its volume with charcoal dust, or, better still, with lampblack,
which, owing to its looseness and fatness, does not detract so much
from the binding qualities of the sand. The utility of the sand may be
tested by pressing the finger into it, whereupon the fine lines of the
skin should appear sharply defined; its binding power is ascertained by
dropping a lump pressed together with the hand from a height, which is
increased until it breaks.
MOLDS OF PLASTER: See Plaster.
«MOLES:»
See also Warts.
Lunar caustic is frequently used to remove warts and moles. It should
be wrapped in tin foil or placed in a quill so that it will not touch
the bare flesh. Moisten the raised surface and touch with the caustic
night and morning. Successive layers of skin will dry up and peel off.
When on a level with the surrounding flesh apply a healing ointment.
Let the last crust formed drop without touching it. Unless carefully
done this process may leave a white scar.
A simple remedy for warts consists in wetting and rubbing them several
times a day in a strong solution of common washing soda. The electric
treatment, however, is now the most popular.
«MORDANTS:»
See also Dyes.
«Mordant for Cement Surfaces.»—Take green vitriol and dissolve it in
hot water. If the cement is rather fresh add 1 part of vinegar for each
part of green vitriol. Best suited, however, is triple vinegar (vinegar
containing 11/13 per cent of acetic acid), which is alone sufficient
for well-dried places. For such surfaces that have been smoothed with a
steel tool and have hardly any pores, take alcohol, 1 part, and green
vitriol, 10 parts, and apply this twice until the iron has acquired a
yellowish color. This mordant forms a neutral layer between cement and
paint, and causes the latter to dry well.
«Mordant for Gold Size.»—A mordant for gold size gilding that has been
thoroughly tested and found to be often preferable to the shellac-mixed
article, is prepared from yolk of egg and glycerine, The yolk of an
egg is twirled in a cup and up to 30 drops of glycerine are added to
it. The more glycerine added, the longer the mordant will take to dry.
Or else an equal portion of ordinary syrup is mixed with the yolk of
egg. Same must be thinly liquid. If the mass becomes too tough it is
warmed a little or thinned with a few drops of warm water. A single
application is sufficient. Naturally, this style of gilding is only
practicable indoors; it cannot withstand the influence of moisture.
«MORTAR, ASBESTOS.»