occupation of the little beings that claim our protection and care. It
should, however, be always borne in mind, that the muscular exercise of
very young children must be of the gentlest class. Prejudice and ignorance
frequently induce nurses and parents to teach their children to walk, as
they falsely call it, and thus their feeble limbs are urged to make
premature efforts to totter along, before the bones and muscles have
acquired sufficient strength to support the body in an erect position.
From this course the legs and joints frequently become bent and
misshapened, and severe injuries are often inflicted on the head and body
by blows and falls. It should never be forgotten, that crawling and
rolling are their first modes of progression, and require the least
exertion. Next comes the sitting posture; from this the child gradually
advances to the erect one; then to walk by slight assistance; and, lastly,
to walk safely alone. All this should come naturally, and never be
promoted, further than by laying the infant on the carpet or floor, for
the full exercise of its little strength. As soon as a healthy child is
able to walk instead of crawl, its own disposition induces it to do so.
The faculty of imitation, the spirit of enterprise, and the pride of doing
what others do, present even in infancy, is rather apt to lead the infant
to over-exertion than the contrary. The practice of constantly 'dolling'
children in the arms is most prejudicial to the early development of their
feeble powers.
It is injudicious to take an infant out during the hottest part of the day
in summer; such a proceeding tends to enervate and depress, rather than to
strengthen him. Whenever he goes out his head should be protected from the
direct rays of the sun by means of a large brimmed hat made of cotton or
straw and an umbrella. The neglect of these precautions frequently gives
rise to the disordered stomach, sickness, and diarrh[oe]a, so prevalent
during very hot weather. During other periods of the day, the weather
being favorable and the locality healthy, an infant cannot be too much out
of doors, especially during teething.
Infants of three or four months' old may, under certain precautions, be
sent out into the open air during the winter. They must be well wrapped
up; they should be carried in the nurse's arms, and not consigned to a
perambulator; they should never go out in foggy nor wet weather; if the
wind be neither in the east nor the north-east there will be no objection
to their being sent out on a clear frosty day. Spring is a trying period
for infants and children, because of the prevalence of east winds; hence
the necessity of seeing that they are well and warmly clad when sent out
during this season. There is much less danger of a child taking cold
during the autumn than the spring, as in autumn the winds frequently blow
from the south, or warm quarter.
In childhood the exercise should be regulated according to constitution
and age; avoiding inactivity, on the one hand, and excessive exercise on
the other. The out-door plays and pastimes of BOYS will generally be found
sufficient, and in some cases will even require to be curbed, to prevent
fatigue and the overtasking of the young frame. With girls it is
frequently difficult to find sufficient exercise without trespassing on
the prejudices of the ignorant, or the routine of their daily education.
With them walking, and some healthy amusement, as skipping, hooping, or
the like, should be indulged in for some hours daily. When this is
impossible or inconvenient, they may be habituated to the practice of the
more simply and cleanly portion of the domestic duties. In the performance
of the latter, the health will be promoted, whilst the care and attention
which is always due by a female to herself and others, at all periods of
her life, will become an easy acquisition, and assist the cultivation of
the best feelings of her nature.
In youth exercise matures and promotes the development of the frame; and
in manhood it is equally necessary, as already noticed, to keep it in
healthy action. In age it will be found to assist the vital functions, and
put off decay. In fact, to all--young, old, rich, and poor, physical
exercise is essential to the permanent enjoyment of health.
In a medical point of view, "exercise, employed moderately, has a tonic
and stimulating influence on the system, and is calculated to prove
beneficial in a great variety of complaints. Used immoderately, it
exhausts both the mental and bodily powers, and produces great debility."
(Pereira.) Well-directed exercise favours the preservation of the general
health, by calling into direct action the majority of the organs of the
body; and it also acts powerfully on the skin, by stimulating its
functions, increasing its temperature, awakening its tone, and subjecting
it to a current of atmosphere favorable to its respiratory offices. But to
be beneficial in the highest degree, exercise must be accompanied by
feelings of present interest and enjoyment. The mind must direct and go
with it; to ensure its full benefits, the "soul must be present."
"During convalescence, properly regulated exertion is highly serviceable;
but it should never be carried so far as to produce exhaustion, and should
be pursued for some time in doors, before it be attempted in the open air;
the latter, at first, should always take place in a carriage, that can be
opened or closed at will; the patient may then attempt short walks in the
open air; but, in all cases, it is of importance that he is not unduly
fatigued, as, otherwise, injury instead of benefit will be the result. One
of the most serious errors, committed with regard to exertion, is that of
permitting a convalescent to sit up too frequently, or for too long a
time, under the mistaken notion of giving him strength. A patient should
never be allowed to sit up longer than is agreeable to his feelings, and
never so long as to produce a sense of fatigue." (Dr R. E. Griffith.)
The physiological effects of exercise have been studied by numerous
scientific observers. The carefully conducted experiments of Dr Edward
Smith have satisfactorily demonstrated that during bodily exertion the
circulation of the blood through the lungs is much increased in velocity,
that these latter inspire air and eliminate carbonic anhydride in
quantities proportionate to the exercise taken, and that these quantities
show an enormous increase over the amounts of these gases inhaled and
exhaled during a state of rest.
Adopting the recumbent position as unity, Dr Edward Smith has given the
following table, illustrating the quantities of air inhaled during various
forms of exercise:
Lying position 1·
Sitting 1·18
Standing 1·33
Singing 1·26
Walking 1 mile per hour 1·90
Walking 2 miles per hour 2·76
Walking 3 miles per hour 3·22
Walking and carrying 34 lbs. 3·50
Walking and carrying 62 lbs. 3·84
Walking and carrying 118 lbs. 4·75
Walking at 4 miles per hour 5·
Walking at 6 miles per hour 7·
Riding and trotting 4·05
Swimming 4·33
Treadmill 5·50
Since a man takes into his lungs 480 cubic inches of air per minute, in
walking four miles an hour he draws in 2400 cubic inches, and if six miles
3260 cubic inches a minute.[289]
[Footnote 289: Parkes.]
Dr Smith estimated the amount of carbonic anhydride evolved under
differing conditions, and found that--
Carbonic acid exhaled
per minute in grains.
During sleep 4·99
Lying down, and almost
asleep (average of three
observations) 5·91
Walking at the rate of 2
miles an hour 18·10
Walking at the rate of 3
miles an hour 25·83
Working at the treadmill,
ascending at the rate of
26·65 feet per minute (average
of three observations) 44·97
The relative amounts of carbonic anhydride eliminated from the lungs
during periods of rest and exercise have also been investigated by
Pettenkofer and Voit. The following table, which gives the results of
their experiments, also records the quantities of oxygen absorbed, and of
water and urea excreted at the same time:--
-----------------------------------------------------------
| | Elimination in Grammes of-- |
|Absorption|------------------------------|
|of Oxygen | | | |
| in |Carbonic| Water. | Urea. |
|Grammes. | Acid. | | |
|-----------------------------------------|
Rest-day. | 708·9 | 911·5 | 828·0 | 37·2 |
Work-day. | 954·5 | 1284·2 | 2042·1 | 37·0 |
| | | | |
Excess on | } | | | |
work-day | } | | | |
(with exception| } 246·6 | 372·7 | 1214·1 | 0·2 |
of urea) | } | | | |
-----------------------------------------------------------
If the quantities in the above table be converted into ounces it will be
found that nearly 8-3/4 oz. more oxygen were absorbed and 13 oz. more of
carbonic anhydride eliminated by the lungs during a work-day than during a
rest-day.[290] It must be stated that during the work-day an interval of
rest was taken, and that the labour was by no means excessive.
[Footnote 290: Parkes.]
Hirn and Speck appear to have conclusively proved that the formation of
the carbonic anhydride occurs in the muscles, and that it is rapidly
carried off from them. In short, this latter result seems essential for
the development of muscular energy. At any rate it is found that if the
respiratory movements be in any way interfered with during exercise, and
the elimination of carbonic anhydride in any degree checked, the muscular
power rapidly diminishes.
An examination of Pettenkofer and Voit's table shows that exercise gives
rise to the escape of a large amount of water from the body, and to a
slightly diminished quantity of urea.
Since the accumulation of the superfluous carbon supplied by the food
gives rise to morbid and diseased states of the body,[291] we shall now be
enabled to understand why deficient exercise should be a source of
physical ill-being, and why, on the contrary, the proper use of the
muscles should be so essential a condition for the maintenance of health,
since it is in them that the great formation of the eliminated carbon is
effected. We shall also not fail to see why, since during exercise the
excretion of water is so largely increased, the blood necessarily becomes
less diluted and richer in quantity.
[Footnote 291: "Deficient exercise is one of the causes which produce
those nutritional alterations in the lung which we class as
tuberculosis."--PARKES.]
Whilst insufficiency of exercise gives rise to a weak action of the heart,
and very frequently to fatty degeneration of that organ, exercise that is
not excessive, although it increases the beats of the heart from ten to
thirty beyond this acceleration, and imparting greater force to the
pulsations, does not interfere with their regularity. Furthermore,
muscular exercise, by considerably augmenting the flow of the blood
through the whole body, the heart included, exercises a most beneficial
function, "since it causes in all organs a more rapid outflow of plasma
and absorption--in other words, a quicker renewal. In this way also it
removes the products of their action, which accumulate in organs, and
restores the power of action to various parts of the body."[292]
[Footnote 292: Parkes.]
Palpitation, enlargement, and valvular disease of the heart result from
excessive or injudicious exercise. Wherever, therefore, fatigue or
embarrassment of the heart shows itself rest must be had recourse to.
Persons having weak hearts suffer greatly in ascending mountain or other
heights.
The effect of exercise upon the kidneys is to diminish the quantity of
water, as well as the chloride of sodium and other chlorides in the urine.
As we have seen, the urea is very slightly lower; but after much exertion
the uric acid is increased. There is also a slight increase in the amounts
of sulphates and carbonic anhydride. Parkes could find no alteration in
the phosphates. The diminution of water and the chlorides is due to the
excretion of these by the skin, the function of which is greatly augmented
by exercise. No urea escapes by the skin, but many acids (probably fatty
ones) are liberated by that organ. Speck has shown that during exercise
the amount of fluid is nearly double what it is when the body is
quiescent.
This escape of fluid by perspiration doubtless affords an explanation of a
diminution in the quantity of the excreta from the bowels. The fæces
exhibit no decrease in nitrogen.
Exercise increases the growth of the muscles, making them at the same time
harder, and also causing them to obey more readily the behests of the
will. Prolonged or excessive exertion, without sufficient rest, has been
found to interfere with their nutrition, and to cause them to become soft.
There is a tolerably general impression that much exercise tends to
cripple the development of the mental faculties, and this idea is said to
have received support from the circumstance that the athletes at our
universities seldom signalise themselves in contests of learning. But this
fact, it has been suggested, may be explained by the athletic exercise
being indulged in to such an extent as to leave no time for cultivating
the mind. If an illustration were required to prove that great bodily
energy is quite consonant with mental vigour it might be found in the life
of the late Professor Wilson, of Edinburgh. On this point Dr Parkes says:
"Considering that perfect nutrition is not possible except with bodily
activity, we should infer that sufficient exercise would be necessary for
the perfect performance of mental work."
As regards the changes that take place in the muscles during exercise Dr
Parkes writes: "The chief changes that take place in the muscles during
action appear to be these: there is a considerable increase of temperature
(Helmholtz), which, up to a certain point, is proportioned to the amount
of work; it is also proportioned to the kind, being less when the muscle
is allowed to shorten than if prevented from shortening (Heidenhain); the
neutral or alkaline reaction of the tranquil muscle becomes acid from
para-lactic acid and acid potassium phosphate; the venous blood passing
from the muscles becomes much darker in colour, is much less rich in
oxygen, and contains much more carbonic acid (Sczelkow); the extractive
matters soluble in water lessen, those soluble in alcohol increase
(Helmholtz, in frogs); the amount of water increases (in tetanus, J.
Ranke), and the blood is consequently poorer in water; the amount of
albumen in tetanus is less, according to Ranke, but Kühne has pointed out
that the numbers do not justify the inference."
Liebig stated that the creatin is increased (but this was an inference
from old observations on the extractum carnis of hunted animals, and
requires confirmation). Sarokin has stated the same fact in respect to the
frog. The electro-motor currents show a decided diminution during
contraction.
That great molecular changes go on in the contracting muscles is certain,
but their exact nature is not clear; according to Ludimar Hermann there is
a jelly-like separation and coagulation of the myosin, and then a
resumption of its prior form, so that there is a continual splitting of
the muscular structure into a myosin coagulum, carbonic acid, and a free
acid, and this constitutes the main molecular movement. But no direct
evidence has been given of this.
The increased heat, the great amount of carbonic acid, and the
disappearance of oxygen, combined with the respiratory phenomena already
noted, all seem to show that an active oxidation goes on; and it is very
probable that this is the source of the muscular action. The oxidation may
be conceived to take place in two ways--either during rest oxygen is
absorbed and stored up in the muscles, and gradually acts there, producing
a substance which, when the muscle contracts, splits up into lactic acid,
carbonic acid, &c.; or, on the other hand, during the contraction an
increased absorption of oxygen goes on in the blood, and acts on the
muscles, or on the substances in the blood circulating through the
muscles. The first view is strengthened by some of Pettenkofer and Voit's
experiments, which show that during rest a certain amount of storage of
oxygen goes on, which no doubt in part occurs in the muscles themselves.
Indeed, it has been inferred that it is this stored-up oxygen, and not
that breathed in at the time, which is used in muscular action. The
increased oxidation gives us a reason why the nitrogenous food must be
increased during periods of great exertion.
An increase in the supply of oxygen is a necessity for increased muscular
action; but Pettenkofer and Voit's observations have shown that the
absorption of oxygen is dependent on the amount and action of the
nitrogenous structures of the body, so that, as a matter of course, if
more oxygen is required for increased muscular work, more nitrogenous food
is necessary. But, apart from this, although experiments on the amount of
nitrogenous elimination show no very great change on the whole, there is
no doubt that, with constant regular exercise, a muscle enlarges, becomes
thicker, heavier, contains more solid matter, and, in fact, has gained in
nitrogen. This process may be slow, but it is certain; and the nitrogen
must either be supplied by increased food, or be taken from other parts.
So that, although we do not know the exact changes going on in the
muscles, it is regarded as certain that regular exercise produces in them
an addition of nitrogenous tissue.
Whether this addition occurs, as usually believed, in the period of rest
succeeding action, when in some unexplained way the destruction which it
is presumed has taken place is not only repaired, but is exceeded (a
process difficult to understand), or whether the addition of nitrogen is
actually made during the action of the muscle, must be left undecided for
the present.
The substances which are thus oxidised in the muscle or in the blood
circulating through it, and from which the energy manifested as heat or
muscular movement is believed to be derived, may probably be of different
kinds. Under ordinary circumstances the experiments of Fick and
Wislicenus and others, and the arguments of Traube, seem sufficient to
show that the non-nitrogenous substances, and perhaps especially the fats,
furnish the chief substances acted upon. But it is probable that the
nitrogenous substances also furnish a contingent of force. The exact mode
in which the energy thus liberated by oxidation is made to assume the form
of mechanical motion is quite obscure.
There seems little doubt that the exhaustion of muscles is chiefly owing
to two causes--first and principally to the accumulation in them of the
products of their own action (especially para-lactic acid); and secondly,
from the exhaustion of the supply of oxygen. Hence rest is necessary, in
order that the blood may neutralise and carry away the products of action,
so that the muscle may recover its neutrality and its normal electrical
currents, and may again acquire oxygen in sufficient quantity for the next
contraction.
In the case of all muscles these intervals of action and of exhaustion
take place, in part even of the period which is called exercise; but the
rest is not sufficient entirely to restore it. In the case of the heart
the rest between the contractions (about two thirds of the time) is
sufficient to allow the muscle to perfectly recover itself.
The foregoing remarks on the effects of muscular exercise will have
prepared us for the inference which statistics abundantly support, viz.
that, other conditions being favorable, the healthiest occupation is that
which consists in the practice (of course within reasonable limits) of
manual labour in the open air.
The Rev. Professor Haughton, in his work entitled 'A New Theory of Manual
Labour,' has drawn up a table (which we append) of the amount of force
expended during various kinds of work. It represents the number of tons
lifted one foot per diem:--
------------------------------------------------------------------------
Labouring Force of Man.
----------------------------------+-------------------------+-----------
Kind of Work. | Amount of Work. | Authority.
----------------------------------+-------------------------+-----------
Pile-driving | 312 tons lifted 1 foot. | Coulomb.
Pile-driving | 352 " " | Lamaude.
Turning a winch | 374 " " | Coulomb.
Porters carrying goods, | 325 " " | "
and returning unladen | |
Pedlars always loaded | 303 " " | "
Porters carrying wood up a stair, | 381 " " | "
and returning unloaded | |
Paviours at work | 352 " " | Haughton.
Military prisoners | 310 " " | "
at shot drill (3 hours), | |
and oakum-picking and drill | |
Shot drill alone (3 hours) | 160·7 " " | "
----------------------------------+-------------------------+-----------
Professor Haughton has devised a formula by means of which a certain
amount of walking exercise may be made to represent its equivalent in
manual labour. He points out that walking on a level surface is equivalent
to raising one twentieth part of the weight of the body through the
distance walked.
When ascending any height, the whole weight of the body is, of course,
raised through the ascent. The formula is--
(W + W_{l}) × D
---------------
20 × 2240
where W is the weight of the person; W_{l} the weight carried (if any); D
the distance walked in feet; 20 the co-efficient of traction; and 2240 the
number of pounds in a ton. The result is the number of tons raised one
foot. To get the distance in feet 5280 must be multiplied by the number of
miles walked.
Supposing a man to weigh 150 lbs. with his clothes, by the employment of
the above formula we should arrive at the following results:--
+----------------------+------------+
| |Work done in|
| Kind of Exercise. |tons lifted |
| | 1 foot. |
+----------------------+------------+
| Walking 1 mile | 17·67 |
+----------------------+------------+
| Walking 2 miles | 35·34 |
+----------------------+------------+
| Walking 10 miles | 176·7 |
+----------------------+------------+
| Walking 20 miles | 353·4 |
+----------------------+------------+
| Walking 1 mile | |
| and carrying 60 lbs.| 24·75 |
+----------------------+------------+
| Walking 2 miles | |
| and carrying 60 lbs.| 49·5 |
+----------------------+------------+
| Walking 10 miles | |
| and carrying 60 lbs.| 247·5 |
+----------------------+------------+
| Walking 20 miles | |
| and carrying 60 lbs.| 495 |
+----------------------+------------+
From the above data something like a rough approximation may be formed of
the daily amount of exercise requisite for a healthy male adult.
Since 500 tons lifted a foot is extremely hard work, the number of miles
corresponding to this extreme amount of labour would, if persevered in, be
objectionable.
Dr Parkes, regarding 300 tons lifted a foot as an average day's work for a
healthy man, thinks that walking exercise equivalent to half that amount
should be taken daily. This, or a 150 tons, represents a nine miles'
walk. He, however, qualifies the suggestion by adding "that, as there is
much exertion taken in the ordinary business of life, this amount may be
in many cases reduced;" and concludes by saying, "It is not possible to
lay down rules to meet all cases, but probably every man with the above
facts before him could fix the amount necessary for himself with tolerable
accuracy."
For muscular exercise to be safe and efficient, it must be taken under
certain conditions and precautions. We have noticed the evil effects of
immoderate bodily exertion on the heart. The lungs are no less seriously
affected by an excessive indulgence in it, which shows itself in spitting
of blood and in congestion of the pulmonary vessels. Congestion of the
lungs brought on by overtaxed bodily strength very frequently causes the
death of horses in the hunting field.
These facts, therefore, not only point to the importance of avoiding undue
or extreme exertion,[293] but also to the necessity of ensuring the full
and uncramped play of the respiratory organs during exercise, and the
consequent removal of any impediment in the way of tight clothing that in
any manner interferes with their freedom of exercise. Laboured respiration
and sighing are indications of pulmonary congestion, and counsel temporary
rest and abstention from exercise.
[Footnote 293: "There must be proper intervals of rest, or the store of
oxygen, and of the material in the muscles which is to be metamorphosed
during contraction, cannot take place."
--PARKES.]
The great augmentation in the excretion of carbon which leaves the lungs
in the form of carbonic anhydride during exercise has been already
referred to. As this carbon is derived from the food, it follows that in
the intervals of exercise an increase of carbonaceous diet is necessary.
For this purpose physiologists prefer the fatty to the amylaceous
varieties of diet. It has been already stated why at the same time the
nitrogenous food must be increased during periods of great exertion. There
seems little doubt that water is the best drink that can be taken during
moderate as well as great exercise.... It is best taken in small
quantities and frequently. Spirits are decidedly prejudicial, and
indispose to bodily exertion. They are hurtful because they lessen the
exhalation of carbonic anhydride from the lungs. Trainers never allow
them, and but very little wine or beer.
The thirst that not unfrequently accompanies exercise is due to the great
escape of water from the skin which has been already alluded to. This
liberation of moisture, being also accompanied, as already explained, by a
large excretion of the chlorides and, perhaps, by other salts. Dr Parkes
advises the use of an additional supply of chloride of sodium to the diet
of those taking much exercise; he suggests that probably potassium
chloride and phosphate might be added with advantage.
The evaporation from the skin has the effect of reducing the bodily
temperature and rendering it equable. This temperature, however, falls
very rapidly after exertion is over; and hence at this time it is always
advisable to guard against the chance of a chill by covering the body
over. Flannel forms the best protection. Keeping the skin clean by daily
ablution greatly aids in the escape of fluid during exercise.
The large amount of carbonic anhydride given off by the lungs during
bodily exercise explains the advantages of open air exercise, and why
walking in the fresh air produces such excellent effects in some forms of
dyspepsia. This increased exhalation of carbonic anhydride also points to
the importance of thorough ventilation when indoor exercise is taken,
particularly by large bodies of men or women, as in riding schools and on
the treadmill. The mortality amongst miners, whose labour is performed in
confined and ill-ventilated spaces is very great. According to Mr Simon,
with the exception of those who work in the well-ventilated mines of
Durham and Northumberland, the 300,000 miners in England break down
prematurely from bronchitis and pneumonia, caused by the atmosphere in
which they are compelled to work.
=EXPAN'SION.= All substances, solid, liquid, and gaseous, when chemical
change does not take place, expand by heat, and contract by cold. In some
of them this property occurs in a greater degree than in others, but is
constant for the same substance under the same circumstances. The chemist
avails himself of this property in the construction of his thermometer;
the wheelwright, in fixing on the tire of his wheels; the engineer, in
restoring to the perpendicular the leaning walls of buildings, &c.
This expansion by heat is of great importance in the manufactures, as
allowance has to be made of it in every purpose where metals are employed.
The following is a list of the expansion of the chief metals, &c., when
heated from 32° to 212° Fahr., or from 0° to 100° Cent.:--
_Substance._ _Expansion._
In bulk. In length.
Glass 1 in 384 1 in 1150
Platinum 1 in 377 1 in 1311
Steel 1 in 309 1 in 926
Iron 1 in 282 1 in 846
Gold 1 in 227 1 in 682
Copper 1 in 194 1 in 582
Brass 1 in 179 1 in 536
Silver 1 in 175 1 in 524
Tin 1 in 172 1 in 516
Lead 1 in 117 1 in 351
Zinc 1 in 113 1 in 340
Of the liquids, they expand as follows, when heated from 0° to 100°
Cent., or from 32° to 212° Fahr.:--
Mercury 1 in 55 in bulk.
Water 1 in 21 in bulk.
Gases practically all expand alike; that is to say, for every degree
Fahrenheit a gas expands 1/491 of its bulk at 32°, and for every degree
Centigrade 1/273 of their volume at 0°C.
An example will show the importance of this. Suppose an iron bar,
connecting two sides of a building, and of a length of about 85 feet. The
increase in length by heat of this bar would make it 1 inch longer in
summer than in winter; and it would, if no allowance be made, pull or
thrust the walls to this extent each year.
=EXPEC'TORANTS.= _Syn._ EXPECTORANTIA, L. Medicines that promote the
secretion of the trachial and bronchial mucus. According to Dr Good, true
expectorants are "those medicines which rather promote the separation of
the viscid phlegm with which the bronchiæ are loaded, than simply
inviscate and dilute it; though these are also treated as expectorants by
many writers." Ammoniacum, antimonials, assaf[oe]tida, the balsams of Peru
and tolu, benzoic acid, benzoin; the fumes of vinegar, tar, and several of
the volatile oils; garlic, ipecacuanha, the oleo-resins, squills,
tartarised antimony, and the smoke of tobacco and stramonium, are among
the principal substances commonly called expectorants. Tartarised
antimony, squills, chlorine, and ammoniacal gases, have also been used
(diluted) to provoke the coughing and favour the expulsion of foreign
bodies from the air-passages; and also to favour the expectoration of
mucus, pus, and membranous concretions, when the local irritation is not
sufficiently great. (Schwilgue.) Expectorants are commonly employed in
pulmonary complaints and affections of the air tubes, attended by a
vitiated state of the mucus, or an imperfect performance of the natural
functions of the secretory vessels. "Of all classes of the materia medica,
none are more uncertain in their action than expectorants." (Pereira.) The
act of ejecting matter from the chest is called EXPECTORATION.
=EXPER'IMENTS= are acts or operations intended to develop some unknown
fact, principle, or effect; or to establish or demonstrate it, when
discovered. Similar operations, performed merely for amusement, are also
often, though incorrectly, called by this name. In rational experiments
these two objects are combined. To experimental research is due the
present high state of advancement and usefulness of the various sciences
most intimately connected with our happiness and well-being. The danger of
taking things for granted has been thus pleasantly and instructively
pointed out by Archbishop Whately:--"It was objected to the system of
Copernicus, when first brought forward, that if the earth turned on its
axis, as he represented, a stone dropped from the summit of a tower would
not fall at the foot of it, but at a great distance to the west; in the
same manner as a stone dropped from the masthead of a ship in full sail
does not fall at the foot of the mast, but towards the stern. To this it
was answered, that a stone, being a part of the earth, obeys the same
laws, and moves with it; whereas it is no part of the ship, of which,
consequently, its motion is independent. The solution was admitted by
some, but opposed by others; and the controversy went on with spirit; nor
was it till one hundred years after the death of Copernicus that, the
experiment being tried, it was ascertained that the stone, thus dropped
from the head of the mast, _does_ fall at the foot of it."
=EXPORTATION.= (EXPORTATION ON DRAWBACK.) By law, a certain allowance, or
drawback of duty, is payable on certain articles, when exported from any
part of the United Kingdom, either as merchandise or ship stores. Thus:--
SUGAR, refined in the United Kingdom, from 4_s._ to 6_s._ per cwt.,
according to quality.
TOBACCO, manufactured in the United Kingdom, 3_s._ 3_d._ per lb. The full
drawback is only allowed on normal tobacco, which contains 13 per cent. of
moisture. If the moisture exceeds 13 per cent., a proportionate reduction
is made in the drawback; if it is found less than 13 per cent., a
proportionate increase is granted.
SNUFF is entitled to drawback at 3_s._ 3_d._ per lb., subject, however, to
an increase if the moisture is less than 13 per cent., and the inorganic
matter not over 18 per cent., and to a decrease if the moisture in organic
matter exceeds these per-centages.
BEER. The amount of this drawback is proportional to the quantity of malt
or sugar used in the brewing of the beer, and is nearly equivalent to the
duty originally paid on such malt or sugar. It is computed according to
the following scale:--For every barrel, or 36 gallons of beer, the
original gravity of which was not less than 1040°, a drawback of 4_s._
3_d._, and for every additional 5 degrees, from 1040° to 1125° inclusive,
a further sum of 6_d._ per barrel.
SOLIDIFIED WORTS, made by a licensed brewer, from malt or sugar, or malt
and sugar, a drawback of 2_s._ 10-5/100_d._ per 28 lbs.
MALT. Under certain restrictions, a drawback of the duty charged, after
deducting 7-1/2 per cent. of the measured quantity.
SPIRITS, from 10_s._ to 10_s._ 3_d._ per proof gallon.
In all cases samples are taken by the Custom House officer, and forwarded
to the Inland Revenue laboratory, where they are examined previous to the
payment of the drawback.
=EXPRES'SION.= In the _useful arts_, the mechanical operation by which a
fluid contained in the pores or cells of a solid is pressed out or
expelled. Many of the fluid substances employed in pharmacy and chemistry
are obtained by expression. Thus, the unctuous vegetable oils, as those
of almonds, linseed, &c., are procured by submitting these substances to
powerful pressure between iron plates, which are either made warm, or the
bruised seeds are previously exposed in bags to the steam of boiling
water. The juices of fresh vegetables are also obtained by expression. The
substances are first bruised in a marble mortar, or, on the large scale,
in a mill, and immediately submitted to the press, to prevent them passing
into a state of fermentation, which would injure the quality of the
product. Fruits which contain highly flavoured or fragrant seeds, or which
have rinds containing essential oil, are generally deprived of them before
being sent to the press. The subacid fruits are also allowed to lay
together for some days before pressing them, as the quantity and quality
of the product is thereby increased. The fluid matter absorbed by the
ingredients employed in the preparation of tinctures, infusions,
decoctions, extracts, &c., is generally obtained by powerful pressure.
Expression is also frequently had recourse to for the purpose of obtaining
solids in a state of purity, as in the expulsion of olein from stearin,
water from bicarbonate of soda, &c. On the small scale, the common
screw-press, or one of like construction, is usually employed; but the
power thus obtained is insufficient to expel the whole of a fluid diffused
through the pores of a solid. Hence has arisen the use of the hydraulic
press, which is now almost alone employed on the large scale. In all these
cases the substances are placed in bags made of haircloth, or coarse
canvas, previously to their being submitted to pressure. For tinctures and
like pharmaceuticals, a small screw-press (TINCTURE PRESS) made of
'galvanised' or tinned iron, and varying in capacity from 1 quart to
several gallons, is employed.
=EXSICCA'TION.= See DESICCATION.
=EX'TRACT.= _Syn._ EXTRACTUM, L. Among _chemists_ this term is understood
to apply to the residuum of the evaporation of aqueous decoctions or
infusions of vegetable matter. In _medicine_ and _pharmacy_, it has a less
definite signification, being applied to various preparations obtained by
evaporating the expressed juices, or the decoctions, infusions, or
tinctures of vegetable substances, until a mass, of a solid or semi-solid
consistence is formed. Extracts vary in their nature and composition with
the substances from which they are prepared, and the fluids employed as
solvents. When water is employed as the menstruum, the products (AQUEOUS
EXTRACTS, WATERY E.; EXTRACTA AQUOSA, E. SIMPLICIORA, L.) usually consist
of gum, starch, sugar, albumen, extractive and saline and other matter,
along with the peculiar principles on which the medicinal virtue of the
vegetable depends. When spirit is employed as the solvent, the products
(ALCOHOLIC EXTRACTS; EXTRACTA ALCOHOLICA, L.) contain most of the
substances above enumerated, except the gum and starch, together with
several other substances which are soluble in spirit, but which are either
wholly or nearly insoluble in water; as resins, essential oils, and the
proximate principles of vegetables. These preparations, with scarcely an
exception, are considerably more powerful than the aqueous extracts of the
same vegetables. In some cases proof spirit or under-proof spirit is
employed, when the extracts (SPIRITUOUS EXTRACTS; EXTRACTA SPIRITUOSA, L.)
generally possess properties between those of the above. In other cases,
dilute acetic acid or acidulated water is employed as the menstruum, when
the products (ACETIC EXTRACTS; EXTRACTA ACETICA, L.) possess much greater
activity than when prepared with water; and would in many cases prove
fatal, if exhibited in doses as large as those of the aqueous extracts.
Still more active extracts are obtained by a combination of the last two
menstrua. According to Ferrari, plants treated with rectified spirit of
wine, mixed with 1/36th part of acetic acid, yields extracts of remarkable
activity. On the Continent ether is sometimes used as the menstruum for
the active principles of certain substances, as cantharides, cubebs,
worm-seed, &c. (ETHEREAL EXTRACTS; EXTRACTA ETHEREA, L.) The term 'simple
extract' is applied to an extract prepared from a single plant or
vegetable substance, and the term 'compound extract' to one prepared from
two or more of such substances. The FLUID EXTRACTS (EXTRACTA FLUIDA, L.)
of modern pharmacy are those which are only evaporated to the consistence
of a thin syrup, and then mixed with 1-10th to 1-8th of their volume of
rectified spirit.
_Prep._ The preparation of medicinal extracts may be conveniently
considered under two divisions, viz.--1. The production of a solution of
the soluble portion of the substances operated on; and, 2. The reduction
of this solution by evaporation to the consistence of an extract.
1. PREPARATION OF SOLUTIONS:--The preliminary operations in the
manufacture of extracts are similar to those employed in the preparation
of DECOCTIONS, INFUSIONS, and TINCTURES. The proper quantity of the
ingredients being taken, the whole is well bruised or reduced to coarse
powder, or otherwise divided by slicing with a knife, that every portion
may be fully exposed to the solvent action of the fluid. In some few cases
(as with gentian, &c.) the 'slicing,' or reduction to fragments, is often
conveniently deferred until the action of the menstruum shall have so far
softened the ingredients as to render them of easy division by the knife.
Those substances (as sarsaparilla, chamomiles, &c.) whose medicinal
principles reside in the cortical portion, of which are of easy
solubility, are commonly subjected to the action of the menstruum without
being subjected to any particular preparation.
In the preparation of AQUEOUS EXTRACTS, the ingredients are treated with
water until all the soluble matter that it is desirable to obtain is
dissolved out. There are several methods of effecting this object,
depending upon the nature of the substances acted on. In some cases
maceration in cold water is resorted to; in others percolation with that
fluid in a 'displacement apparatus.' More generally, however, boiling
water is poured on the substance, and is digested on it for some time, as
in the preparation of infusions; or the substance is exhausted by boiling
in water, as in the preparation of decoctions. After the ebullition or
infusion has continued a sufficient time, the heat is removed, and the
liquid portion drawn off. The ingredients are then pressed to extract the
remaining liquid; or they are washed or 'sparged' with hot water, which
expels it by displacement. According to the usual practice in the majority
of cases, a second quantity of water is poured on after the first has been
thoroughly drained off, and the effusion or decoction is repeated a second
and even a third time, or until the ingredients are perfectly exhausted of
their soluble portion. The liquor or liquors thus obtained being allowed
to repose for 15 or 20 minutes, for the purpose of depositing the sand or
other gritty and heavy matter that is mechanically mixed with them, are
carefully decanted from the sediment, and, after being run through a fine
hair-sieve, or flannel bag, are ready for concentration. In some
instances, however, this method proves insufficient to render the liquid
clear. In such cases, the solution may generally be rendered transparent
by clarification with a little white of egg, removing the scum as it
rises, straining the liquid through flannel, as before; or the liquid may
be filtered through a bag made of fine 'Welsh flannel,' or of 'tweeled
cotton cloth' (Canton flannel), both of which should be soaked in clean
water for at least an hour before use. In the small way, filters of linen
or paper are sometimes employed; but as all media sufficiently fine to
render vegetable solutions transparent soon choke up, this filtration is
objectionable, from the length of time it occupies. In some houses the
aqueous infusion or decoction is allowed to repose for 24 hours, and then
decanted and evaporated; but such a plan is objectionable, as, however
smooth and glossy extracts so prepared may appear, their medicinal virtues
are lessened by the lengthened exposure to the atmosphere.
When about one half of an aqueous solution has evaporated, it is often
advantageous to repass it through a flannel or horsehair strainer, to
remove the flocculi that generally form by the action of the heat and air.
This is especially necessary with vegetable solutions prepared without
boiling, and should be adopted whenever a smooth and slightly extract is
desired.
II. REDUCTION OF SOLUTIONS:--The reduction of the solution to the proper
consistence is effected by evaporation. The mode in which this is
performed varies for different extracts. The London College directs that,
"unless otherwise ordered, the evaporation should be conducted as quickly
as possible, in a broad, shallow pan, placed in a water bath, until a
proper consistence is acquired for forming pills; stirring assiduously
with a spatula towards the end of the operation." The Dublin College
orders that "all simple (aqueous) extracts (EXTRACTA SIMPLICIORA), unless
otherwise ordered, are to be prepared by boiling the vegetable matter in 8
times its weight of water, till the liquid is reduced to one half; the
liquor is then to be expressed, and, after a short time allowed for
defecation, to be decanted, filtered, and evaporated in a steam or water
bath, until it begins to thicken, and then finally inspissated by a
reduced heat, with continual stirring, until a consistence for forming
pills be attained." The instructions of the Edinburgh College are similar,
with the one important exception, however, of ordering the evaporation to
be conducted in a water bath saturated with chloride of sodium.
Though the water bath has the sanction of the London College, it is ill
adapted for the purpose to which it is here ordered to be applied, as from
its low evaporative power the advantages which are derived from its
equable temperature are vastly overbalanced by the lengthened exposure of
the solution in a heated state to the action of the atmosphere. It has
been shown that a vegetable extract so prepared is inferior in quality to
a similar one formed by rapid evaporation in a shallow pan over a naked
fire, or placed in a sand bath, provided proper care is taken, and
assiduous stirring is adopted during the whole time of the exposure to
heat. In practice, however, the use of a naked fire is perfectly
inadmissible, as the least neglect on the part of the operator would
probably lead to the incineration of the whole. These objections are
obviated by the addition of the 1/5th part of salt to the water of the
bath, which raises its boiling-point to 218-3/4° Fahr., when the
temperature of the contained extract is fully 212°; the remaining 6° being
lost by the interposition of the substance of the evaporating vessel.
ON THE LARGE SCALE, the evaporation of infusions or decoctions for
extracts is usually conducted in very wide, shallow, copper or
tinned-copper pans, having steam-tight jackets of cast iron, and heated by
steam 'playing' between the two.
The rapid deterioration which vegetable juices and solutions undergo by
exposure to the air, especially at high temperatures, has led to the
introduction of apparatus, by which they may be concentrated without
contact with the atmosphere, and at a less degree of heat than is required
for that purpose in open vessels. Such is the method, commonly called
'Barry's process,' in which the air is removed from certain air-tight
refrigerators by the introduction of steam, which is then condensed by the
application of cold, by which means a partial vacuum is obtained. Another
process for attenuating the atmosphere over the surface of fluids during
evaporation is by the action of an air-pump. This plan was introduced by
Howard, and is commonly applied to the concentration of syrups in the
sugar refineries. Extracts obtained by either of these methods are said to
be prepared 'in vacuo,' and are found in practice to be immensely superior
to the common extracts of the shops, and consequently require to be
exhibited in proportionably small doses.
'The American Journal of Pharmacy' for September, 1877, contains a new
process for the preparation of extracts without heat, by Professor
Herrara. We extract the following from the Professor's paper:--
"The results of my observations have satisfied me that, when the water
partially congeals, the dissolved principles remain in solution in the
mother liquors, and that two or three congelations are generally
sufficient for obtaining the solutions concentrated enough to finish the
extract by exposure upon plates to the heat of the sun, or of a drying
closet, heated to about 30° cent. (86° Fahr.). The extracts prepared by
this method accurately represent the properties of the plants, and the
principles which are changed by the influence of heat remain unaltered;
even the volatile constituents are not dissipated, though most of the
water be removed by freezing. Owing to the small cost of the necessary
apparatus, it appears to me that my process for preparing extracts should
be preferable even in those countries where ice is less readily obtainable
than combustibles.
"Extract of conium prepared with unpurified juice by the process
mentioned, has preserved the characteristic odour of conia, and by
dissolving it in water. I have obtained a solution exactly representing
the juice of the plant in appearance and properties, and giving when
heated an abundant coagulation, proving that even albumen had remained
unaltered. 1750 grams of cow's milk at 9° R., left, after three
congelations, 750 grams of a liquid having a density of 148, and by
evaporation in the sun this left a dry extract of milk, which again formed
that liquid on being dissolved in water. A number of other liquids
similarly treated, gave corresponding results, and it seems to me,
therefore, that medicinal extracts are best prepared by congelation. It
may be objected that the medical juices should be previously purified, but
it should be remembered that coagulated albumen always encloses a
considerable portion of the active principles, and that the heat necessary
to effect the coagulation and the evaporation by means of a water-bath is
sufficient to change many principles; also that the extracts thus prepared
are sometimes inert or less active. The careful experiments made by Orfila
and the clinical experience of others demonstrate that extracts prepared
with unpurified juice are stronger.
"The apparatus employed by me is the so-called sorbetière;[294] for larger
quantities the apparatus of Gougaud is preferable. The frigoric mixture is
composed of ice and sodium chloride, or preferably of crystallised calcium
chloride. After a large portion of the solution has congealed, the mass is
enclosed in a cloth and subjected to pressure, the press-cake of ice is
broken and again pressed, to separate the mother liquor as completely as
possible, and the congelation is repeated two or three times, with the
precaution that it is not carried far enough to cause the precipitation of
the sparingly soluble principles. The mother liquor is then put into
shallow dishes and exposed to the heat of the sun or of a drying room, the
temperature of which does not exceed 30° C. (86° F.) until the extract has
attained the desired consistence."
[Footnote 294: An apparatus similar to that used for ice-cream.]
_Obs._ When water, acidulated with acetic acid, is employed in the
preparation of extracts, the vegetable substances are usually macerated in
it, in the cold, or the dilute acid is sprinkled over the bruised plant in
the fresh or recent state, and the whole is then submitted to strong
pressure, to expel the juice, which is strained and evaporated in the
usual way, but preferably in a well-tinned or plated-copper pan.
ALCOHOLIC and SPIRITUOUS EXTRACTS are prepared by evaporating a filtered
concentrated tincture of the ingredients in any suitable vessel, by which
the volatilized spirit may be saved. In general, rectified spirit is used
as the menstruum; but in some cases proof spirit is employed; and, in
others, the substances are first digested in proof spirit, and afterwards
in water, and the mixed tincture and infusion evaporated in the usual
manner.
ETHEREAL EXTRACTS are obtained in a similar manner to alcoholic ones; but
being merely prepared in small quantities at a time, the process may be
conveniently performed in glass vessels. When it is required to boil
either of the above fluids (alcoholic or ethereal), or any other volatile
liquid on the ingredients, a vessel fitted with a long tube, or a Liebig's
condenser reversed, as noticed under ether, may be used to prevent any
loss of the menstruum.
The INSPISSATED VEGETABLE JUICES (JUICES, E.; SUCCI, L.) of the British
Pharmacop[oe]ia are obtained by expressing the juices from the fresh
plants, and preserving them by the addition of spirit. "By thus preserving
the juice of the plant its properties are not impaired by the action of
the air during the time necessary to dry the leaf for tincture, nor by the
action of both air and heat during the time necessary to evaporate the
juice to the consistence of an extract."--Squire. The directions of the
Edinburgh College for preparing their inspissated juices (SUCCI SPISSATI,
L.) are--"Beat the fresh substance, and press it strongly through a canvas
bag, in order to obtain the juice; which, being put into a wide, shallow
vessel, and heated by means of boiling water saturated with sea-salt, is
to be reduced to the consistence of honey. The mass, when cold, is to be
put into glazed earthen vessels, and moistened with strong alcohol." By
operating in this way a considerable portion of the activity of narcotic
vegetables is lost. Some of their juices, as that of aconite, are impaired
in so short a time as scarcely to compensate for the trouble of preparing
them. This deterioration does not, however, take place in any remarkable
degree, if the expressed juice from the recent vegetable be evaporated by
exposing it in a thin stratum to a current of very dry air, as adopted by
Mr Squire. This may be managed by putting the juice into small, flat trays
or dishes, placed on shelves in a suitably arranged apparatus, alternated
with similar vessels of concentrated sulphuric acid; or by causing a
current of very dry air, at the common temperature of the atmosphere, to
pass over them. It has been shown that 10 gr. of extract, thus prepared,
were more than equal to 20 gr. prepared _in vacuo_; and to more than 60
gr., and in some cases, 90 gr., of those prepared by the common process of
boiling down the juice to an extract.
The concluding portion of the process of extract-making, technically
termed 'finishing-off,' requires the most scrupulous attention. As the
evaporation advances, the heat should be lessened, and as soon as the
extract acquires the consistence of thick treacle it should be removed
altogether, and the remainder of fluid matter evaporated by the heat
retained by the copper pan, the escape of vapour being promoted by
assiduous and laborious stirring with a suitably shaped wooden spatula.
This part of the process should be continued until a proper consistence is
attained and the extract is nearly cold. When high-pressure steam or a
chloride of calcium bath is employed, care must be taken to withdraw the
heat before stirring the semi-liquid mass; as, if an extract having a
temperature of about the boiling-point of water, or even a few degrees
below it, is agitated, it becomes full of bubbles, and appears rough and
puffy, and this appearance cannot be removed by subsequent stirring, or by
any method but redissolving it in water and re-evaporation. This is
especially the case with the extracts of sarsaparilla (simple and
compound), gentian, liquorice, and most others of a similar class. A good
laboratory man knows from experience the proper time for the removal of
the heat, but unpractised persons often fail in this particular. In such
cases should the heat retained by the evaporating pan, and by the extract,
prove insufficient to complete the process, a little more may be
cautiously applied. Without assiduous and laborious stirring in the way
described, a very smooth and glossy extract cannot be produced. To promote
this artificial appearance, some persons add 3% or 4% each of olive oil
and gum arabic, dissolved in water, with about 1% or 2% of spirit of wine.
The consistence of the ordinary extracts of the shops is the same as that
of electuaries and confections, and is described in the Ph. E. as equal to
that of "thick honey." The instructions of the Ph. L. and D., to evaporate
the mass "until it acquires a consistence proper for making pills," except
in 2 or 3 cases (as _Ext. Colocynth. Comp._, &c.), is not adopted, and,
indeed, would be found inconvenient in practice. Extracts evaporated to
such a consistence are commonly termed 'pilular extracts,' and when
evaporated so that they are quite dry, and brittle when cold, they are
called 'hard extracts' (EXTRACTA DURA, L.).
_Pres._ Extracts should be put into pots as soon as taken from the pan,
and, after being carefully and securely tied over with bladder, should be
'stored' in a dry situation. The London College orders "a small quantity
of rectified spirit to be sprinkled upon all the softer extracts, to
prevent them becoming mouldy." A better way is to employ a little spirit,
holding in solution a few drops of oil of cloves, or a still less quantity
of creasote. This should be added to them the last thing before removing
them from the evaporating pan, and when they are nearly cold. The same
object is effected by moistening the inside of the bladder (used to tie
them over) with a few drops of oil of cloves or creasote. Hard extracts
should be kept in bladders or gut skins, placed in stone pots, and well
covered over. With care, extracts prepared from recent vegetable
substances may be preserved twelve months, or from season to season; and
those from dry ingredients, or such as are less inclined to spoil, for
perhaps double that time; but beyond these periods their virtues cannot be
relied on, and they should consequently be discarded, if remaining unused
or unsold.
_Pur., &c._ The quality of an extract cannot be ascertained by mere
inspection, nor is it readily discovered by chemical tests. A knowledge of
these facts has induced the mercenary and fraudulent manufacturer to
employ damaged and inferior drugs in their preparation, alike regardless
of the welfare of the patient and the credit of the practitioner. A common
practice with some manufacturers is, not only to pick out the least
expensive variety of every drug for the preparation of their extracts, but
the most inferior and often damaged and worthless portion of this already
inferior article. The production of a smooth, bright, and glossy extract
is all that is usually attempted by these individuals, and all that is
sought after by the mass of purchasers, who mistake the simulation of the
mere external signs of good quality for its actual existence. It is a
fact, which we can verify from extensive experience in the laboratory,
and from years of practical observation on this point, that extracts
faithfully prepared from good materials do not possess the sightly and
pleasing appearance of those commonly vended by the wholesale druggists.
On comparing the extracts prepared by different metropolitan houses, we
have found that those which have exhibited a remarkably bright and glossy
appearance have been uniformly inferior, and sometimes nearly inert;
whilst others, with a less prepossessing appearance, have been generally
of good quality. These facts are well established by reference to the
extracts of those houses and institutions that are remarkable for the
superior quality of their preparations, and by comparing them with the
common extracts of the shops supplied by the wholesale trade.
A good extract should be--1. Free from grit, and wholly soluble in 20
parts of the menstruum employed in its preparation, forming a nearly clear
solution.--2. It should have a uniform texture and colour, and be of a
proper consistence.--3. If a narcotic or active extract, it may be
exhibited in proper doses, and its effects watched. Its activity may also
be tested on any small animal.--4. An assay for the proximate vegetable
principle (alkaloid, &c.) contained in the plant from which it has been
prepared may be made. The extracts prepared from the expressed juices of
plants, without straining off the coagulated albumen, are, of course,
exceptions to the first test. Unfortunately, these tests are not always
easily performed, and the last two are inapplicable to those extracts that
exercise no very marked physiological action, unless when taken in
repeated doses, long continued. This want of a ready means of accurately
testing the qualities of extracts has enabled the fraudulent manufacturer
to sell inferior articles with impunity, and often without the least fear
or danger of detection.
In general, an extract more than six months old contains only half the
activity of a similar one newly made. When more than twelve months old
they should be rejected as worthless, and the stock renewed.
_Uses, &c._ The extracts of the shops are generally acknowledged to be the
most varying, imperfect, and uncertain class of medicines belonging to
modern pharmacy. They are mostly used in the same cases as the plants from
which they are prepared, but in smaller doses.
_Concluding Remarks._ In the preparation of extracts the great desiderata
to be aimed at are--to suit the menstrua and the methods of manipulating
to the peculiar characteristics of the active constituents of the
vegetable substances operated on. The pharmaceutist should always bear in
mind that a perfect extract should be a concentrated, solid mass,
representing, as near as possible, in medicinal efficacy, the materials
from which it has been prepared, and capable of being redissolved, so as
to form a solution closely resembling that from which it has been derived.
An extract possessing equal strength to the whole mass of the ingredients
from which it has been prepared is almost next to an impossibility,
however desirable such a degree of perfection may be. The medicinal
properties of all solutions of vegetable matter are injured by being
reduced to the solid state; and this deterioration, more or less, takes
place, whether the solvent be water, acetic acid, proof spirit, or
alcohol. The volatile portions (the essential oils, the aroma, &c.) are
nearly or wholly dissipated; and though these do not always form the
principal or active ingredients of the vegetables from which extracts are
prepared, yet they generally exercise a modifying and controlling
influence over the other ingredients, which considerably alters their
therapeutical action. The loss of aroma may often be a trifling
deficiency, but in the extracts of aconite, henbane, hemlock, belladonna,
and other narcotic plants, this is not the case. In these cases it is well
known that the inert preparations are wholly deficient of the odour of the
recent plant, and that in proportion as the odour is developed, so is
their activity preserved. The powerful smell of the recently expressed
juice of hemlock, with the scarcely perceptible odour of the extract
(EXTRACTUM CONII, Ph. L.), offers an excellent example of this fact. The
dose of the one often reaches 20 or 30 gr., whilst that of the other
seldom exceeds 5 or 10 drops, or a portion equivalent in dry ingredients
to considerably less than 1/2 gr.
When extracts are ordered in prescriptions, those of the 'Pharmacop[oe]ia'
should be alone employed by the dispenser, as the substitution of others
for them would not only be violating faith with the prescriber, but might
also produce consequences alike injurious to the dispenser and the
patient. Many medical gentlemen prefer extracts prepared by particular
processes or persons, but such intention is always indicated in their
prescriptions.
=Extract of Ac'onite.= _Syn._ EXTRACT OF WOLFSBANE, E. OF MONKSHOOD,
INSPISSATED JUICE OF ACONITE; EXTRACTUM ACONITI (B. P., Ph. L. E. & U.
S.), SUCCUS SPISSATUS ACONITI (Ph. D. 1826), L. _Prep._ 1. (B. P.) Take
112 lbs. of the fresh leaves and flowering tops, bruise them, press out
the juice, heat it gradually to 130° F., and separate the green matter by
a calico filter. Heat the strained liquor to 200° F. to coagulate albumen,
and again filter. Evaporate the filtrate by a water bath to the
consistence of a thin syrup; then add to it the green colouring matter
previously separated, and stirring the whole together assiduously,
evaporate at a temperature not exceeding 140° F. to a pill
consistence.--_Dose_, 1 to 2 gr.
2. (Ph. L.) Take of fresh leaves of aconite, 1 lb.; bruise them in a stone
mortar, express the juice, and evaporate it, unstrained, to a proper
consistence. The formulæ of the Ph. D. & U. S. are similar.
3. (Ph. E.) Beat the fresh leaves of aconite to a pulp, and express the
juice, then subject the residuum to percolation with rectified spirit
until the latter passes through without being materially coloured; unite
the expressed juice and the percolated tincture, filter, distil off the
spirit, and evaporate in a vapour or a water bath to a proper consistence.
Stronger than the preceding.
_Obs._ A variable and uncertain preparation. Numbness and tingling follow
its application to the limbs or tongue when it is of good
quality.--_Product._ 1 cwt. of fresh leaves yield between 5 lbs. and 6
lbs. of extract. _Prop._ Anodyne, sudorific, and narcotic; very
poisonous.--_Dose_, 1/2 gr. to 2 gr., made into a pill with liquorice
powder; once or twice a day, in neuralgic pains, chronic rheumatism,
glandular swellings, &c., gradually and cautiously increased to 5 or 6 gr.
4. (Alcoholic; E. A. ALCOHOLICUM, L.)--_a._ (P. Cod.) Aconite (in coarse
powder), 1 lb.; proof spirit, 3-1/2 lbs. (say 2-1/2 pints); proceed by the
method of displacement, and when all the spirit has penetrated the
powdered mass, keep this covered with distilled water, until the liquid
begins to cause a precipitate in falling into that which has previously
passed through; next distil the spirit from the tincture, and evaporate
the residuum to the proper consistence.
_b._ (Ph. U. S.) Aconite 1 lb.; spirit, sp. gr. ·935 (= 13 u. p.), 1
quart, or q. s.; as last.
_c._ (Ph. Baden.) From the tincture prepared with rectified spirit, and by
either maceration or displacement. Stronger than the last two.
_d._ (Ph. Bor.) The juice is expressed from the fresh herb, which is then
sprinkled with about 1/3 of its weight of water, and again pressed; the
mixed and strained liquid is evaporated in a vapour bath, at 122° to 140°
Fahr., to about one half; to this, as soon as cold, an equal weight of
spirit (sp. gr. ·900) is added, and after frequent agitation for 24 hours,
the whole is filtered, with pressure; the marc is treated with fresh
spirit (equal to about 1-4th that first used) and again pressed; the mixed
liquors are next filtered, and are, lastly, evaporated, as before, to the
proper consistence.
_Obs._ Resembles the simple extract, but is much more powerful. It has
been exhibited internally in the form of pills, and used externally,
combined with ointment or spread on simple plaster.--_Dose_, 1/12 to 1/6
gr. every three hours.
5. (Ammoniated; E. A. AMMONIATUM, L.--Dr Turnbull.) Extract of aconite, 1
dr.; liquor of ammonia (strongest), 10 or 12 drops; mix.
6. (Dried); E. A. SICCUM, L.--P. Cod.) The expressed juice, strained
through a sieve or coarse linen, is at once, without depuration, exposed
in earthen dishes, in layers of about 2 lines deep, in a stove or current
of dry air, to a temperature ranging between 95° and 104° Fahr., until
reduced to dryness. The dried extract is to be packed in bottles.
7. (Saccharated; E. A. SACCHARATUM, L.) From extract of aconite (Ph.
Bor.), 4 oz.; sugar of milk (in powder), 1 oz.; mix, and dry the mass in a
warm place, adding sugar of milk, q. s. to make the whole equal in weight
to that of the extract used (4 oz.). An excellent preparation, which keeps
well. The other NARCOTIC EXTRACTS, as those of BELLADONNA, HEMLOCK,
HENBANE, &c., are to be treated in a similar manner. See ACONITE, and
_below_.
=Extract of Aconite Root.= _Syn._ EXTRACTUM ACONITI RADICIS ALCOHOLICUM,
L. _Prep._ (Dr Fleming; Dr Turnbull.) From a tincture of the root made
with rectified spirit. It is said to be 12 times as strong as the extract
of the leaves.
=Extract of Ag'aric=. _Syn._ EXTRACTUM AGARICI, L. _Prep._ (P. Cod.) From
the infusion of white agaric (_Polyporus officinalis_) prepared with cold
water. Purgative.--_Dose_, 1 to 4 gr.
=Extract of Alcorno'co.= _Syn._ EXTRACTUM ALCORNOCÆ, L. _Prep._ From a
decoction of alcornoco bark (South American). Astringent and
tonic.--_Dose_, 5 to 20 gr. in phthisis, &c.
=Extract of Al'oes.= _Syn._ PURIFIED ALOES, WASHED A.; EXTRACTUM ALOËS
BARBADENSIS (B. P.), EXTRACTUM ALOËS (Ph. L.), E. A. AQUOSUM (Ph. D.), L.
_Prep._ 1. (B. P.) Barbadoes aloes, in small pieces, 1 lb.; treated with 1
gall. of boiling water for 12 hours, and the clear liquid
evaporated.--_Dose_, 1 to 3 gr. B. P. 2 to 6 gr.
2. (B. P.) Socotrine aloes, 1 lb., treated with 1 gall. of boiling water
for 12 hours, and the clear liquid evaporated to dryness.
3. (Ph. D.) Aloes (hepatic), 4 oz.; water, 1 quart; boil till dissolved;
when cold, decant the clear liquid, and evaporate as before.
4. (Ph. Bor. 1847.) By macerating powdered aloes in cold water for 48
hours, with frequent agitation, and then evaporating in a water bath at a
temperature not exceeding 150° to 165° Fahr., until a pilular consistence
is attained.
_Obs._ The second is the form commonly adopted in the laboratory. When
made with the juice of borage, burgloss, &c., it forms the old 'ALOES
INSUCCATA,'--_Dose_, 5 to 15 gr. See ALOES and EXTRACT OF BARBADOES ALOES.
=Extract of Aloes, prepared with Sulphuric Acid.= _Syn._ EXTRACTUM ALOËS
ACIDO SULFURICO CORRECTUM (Germ. Ph.). _Prep._ Dissolve extract of aloes,
8 ounces, in distilled water 32 ounces, then gradually add sulphuric acid,
1 oz. (by weight), and evaporate to a dry extract.
=Extract of Anem'one.= See EXTRACT OF PASQUE FLOWER.
=Extract of Angel'ica.= _Syn._ EXTRACTUM ANGELICÆ, L. _Prep._ 1. (Ph.
Baden.) From a tincture of the root, prepared with spirit sp. gr. ·944 (=
21-1/2 u. p.).
2. (Ph. Bor.) Angelica root and rectified spirit, of each 2 parts; water,
9 parts; digest, strain, and evaporate. Inferior to the preceding.
3. (Dr Moir.) Angelica root, 2 lbs.; rectified spirit, 1 gall.; make a
tincture; to the 'marc' add proof spirit, 1 gall., and repeat the
digestion; filter the two tinctures separately, mix, distil off the
spirit, and evaporate. Balsamic, stomachic, and tonic.--_Dose_, 10 to 20
gr. The last is the most balsamic and agreeable.
=Extract of Ap'ples.= _Syn._ CHALYBEATED E. OF A.; EXTRACTUM FERRI
POMATUM, L. _Prep._ 1. (Ph. Bor.) Crab-apples (unripe), 6 lbs.; peel them
and reduce them to a pulp; add iron wire (in small coils), 1 lb.; digest
in a vapour bath for about a week, express, strain, decant, and evaporate
in a porcelain vessel, with constant stirring, to the consistence of a
soft extract; dissolve the residuum in water, 4 parts, strain and
evaporate as before.--_Dose_, 5 to 10 gr.; as a chalybeate tonic. The
formula of the Ph. Baden is nearly similar.
2. (Ph. Germ.) Reduce 5 lbs. of unripe apples to a pulp; mix them with cut
straw, and press. To the strained juice after removal of the sediment add
1-1/2 oz. of reduced iron. When this has dissolved, to the cooled liquid
add as much water as will make up 4-3/4 lbs. Filter, and reduce to a thick
extract.
=Extract of Ar'nica.= _Syn._ EXTRACT OF ARNICA FLOWERS; EXTRACTUM ARNICÆ
FLORUM, L. _Prep._ 1. (P. Cod.) From the dried flowers, as ALCOHOLIC
EXTRACT OF ACONITE--P. Cod.
2. (Ph. Græca, 1837.) From a tincture of the flowers, prepared with
rectified spirit, 3 parts, and water, 5 parts.--_Dose_, 2 to 6 gr.; as a
stimulant in various diseases accompanied with debility, deficient nervous
sensibility, paralysis, dropsies, diarrh[oe]a, amenorrh[oe]a, dysentery,
&c.
=Extract of Arnica-Root.= _Syn._ EXTRACT OF ARNICA; EXTRACTUM ARNICÆ
RADICIS, L. _Prep._ 1. (Ph. Baden.) As EXTRACT OF ANGELICA--Ph. Baden.
2. (Ph. Græca.) From tincture of the root, prepared as No. 2 (_above_).
The form of the Hamburg Codex is nearly similar.--_Dose, &c._ As the last.
=Extract of Art'ichoke.= _Syn._ EXTRACTUM CYNARÆ, L. _Prep._ From the
fresh leaves of the artichoke, as EXTRACT OF ACONITE--Ph. L.--_Dose_, 3 to
6 gr., twice or thrice daily; in rheumatism, &c.
=Extract of Aspar'agus.= _Syn._ EXTRACTUM ASPARAGI, L. _Prep._ 1.
(Soubeiran.) From the expressed juice of the shoots, clarified and
evaporated by a gentle heat.
2. From the juice of the roots, as No. 1. Both are diuretic.--_Dose_, 15
gr. to 1/2 dr., or more.
=Extract of Bael.= _Syn._ EXTRACTUM BELÆ LIQUIDUM, L. B. P. Bael, 1;
distilled water, 15; rectified spirit, 1/8; macerate for 12 hours in 5 of
the water, pour off the liquid, repeat the operation twice for 1 hour;
press, filter, and evaporate to 1, including the spirit. A fluid ounce is
equal to a solid ounce.--_Dose_, 1 to 2 dr.
=Extract of Balsam Apple.= _Syn._ EXTRACTUM BALSAMIMÆ. The inspissated
juice of the balsam apple.--_Dose_, 5 to 15 drops in dropsy.
=Extract of Bark.= See EXTRACT OF CINCHONA.
=Extract of Belladon'na.= _Syn._ EXTRACT OF DEADLY NIGHTSHADE, INSPISSATED
JUICE OF BELLADONNA; EXTRACTUM BELLADONNÆ (B. P., Ph. L. E. & D.), SUCCUS
SPISSATUS BELLADONNÆ, L. _Prep._ 1. (B. P.) Take 112 lbs. of fresh leaves
and tender branches, bruise in a stone mortar or other suitable apparatus,
and press out the juice, heat it gradually to 130° F., separate the green
colouring matter by a calico filter, heat the strained liquor to 200° F.
to coagulate the albumen, and again filter; evaporate the filtrate by a
water bath to the consistence of a thin syrup, then add to it the green
colouring matter previously separated, and, stirring the whole together
assiduously, continue the evaporation at a temperature not exceeding 140°,
until the extract is of a suitable consistence for forming pills.--_Dose_,
1/4 to 1/2 gr., gradually increased to 1 or 2 gr.
2. (Ph. E.) Express the juice from the bruised fresh plant, sprinkle the
'marc' with water, and again apply pressure; mix the expressed liquids,
filter them, and evaporate the filtered liquor in a vapour bath to the
consistence of an extract.
3. (Ph. D.) From the leaves, collected when the plant begins to flower.
The expressed juice is allowed to stand for 24 hours, and the clear
portion is decanted; the sediment is placed on a calico filter, washed
with an equal bulk of cold water, and the filtrate mixed with the
expressed juice. The mixed liquid is next heated in a water bath, to
coagulate its albumen, and after being skimmed, and filtered through
flannel whilst hot, the washed sediment is added, and the whole
evaporated, as before.
4. (Ph. U. S.) The expressed juice is heated to the boiling-point,
filtered and evaporated (see _below_).
_Obs._ The P. Cod. directs this extract to be made by two different
formulæ. The product of the one resembles that of the Ph. L.; that of the
other, that of the Ph. E. That of the Ph. L., from retaining the fecula,
is the weakest preparation.--_Dose_, 1/2 gr. to 1 gr., gradually increased
to 3 or 4 gr.; as an anodyne in neuralgia, tic-douloureux, &c.; as an
antispasmodic to relieve rigidity and spasms, in various affections of the
uterus, rectum, urethra, bladder, &c., and in hooping-cough; in various
maladies of the eyes; and as a resolvent and discutient in several
glandular diseases. It has been highly recommended as a preservative
against scarlet fever. It is most frequently employed externally, under
the form of a plaster, ointment, or lotion. It is poisonous.
5. (Alcoholic; E. B. ALCOHOLICUM, L.)--_a._ (P. Cod.) As ALCOHOLIC EXTRACT
OF ACONITE--P. Cod.
_b._ (Ph. U. S.) As the last (nearly), using spirit of ·935 (=about 13 u.
p.).
_c._ (Moir.) The expressed juice is coagulated by heat, cautiously
applied, and filtered; the filtrate is reduced to the consistence of a
syrup, and mixed with an equal volume of nearly anhydrous alcohol (say of
90%); the clear portion is lastly evaporated, as before.
_Obs._ The above is much more powerful than the common extract, and is
chiefly used in external applications. See BELLADONNA, and _below_.
=Extract of Belladonna Ber'ries.= _Syn._ EXTRACTUM BACCARUM BELLADONNÆ, L.
_Prep._ (P. Cod.) From the expressed juice of the berries, evaporated to
the consistence of thick honey.--_Dose_, 1 to 5 gr.
=Extract of Bis'tort.= _Syn._ EXTRACTUM BISTORTÆ, L. _Prep._ 1. (P. Cod.)
From the dried root of bistort or snake-weed (_Polygonum Bistorta_), by
percolation with temperate distilled water.
2. From the infusion made with boiling water, or from the decoction.
Astringent and tonic.--_Dose_, 10 gr. to 1/2 dr.
=Extract of Bit'ter-sweet.= _Syn._ EXTRACT OF WOODY NIGHTSHADE; EXTRACTUM
DULCAMARÆ, L. _Prep._ 1. From the decoction of the stalks.
2. (Ph. U. S.) From the dried stalks, by percolation with temperate water.
Diaphoretic, diuretic, and narcotic.--_Dose_, 3 to 6 gr.; in chronic
asthma, rheumatism, and chest diseases; and particularly in chronic skin
diseases.
=Extract, Black.= See EXTRACT OF COCCULUS.
=Extract of Black Pepper.= See EXTRACT OF PEPPER.
=Extract of Bladder-wrack.= _Syn._ EXTRACTUM FUCI VESICULOSI. From the
dried plant of the bladder-wrack. Given in obesity.
=Extract of Bor'age.= Syn. EXTRACTUM BORAGINIS, L. _Prep._ 1. (P. Cod.)
From the dried herb (_Borago officinalis_).
2. (Ph. Lusit.) From the clarified juice of the fresh plant. Exhilarating,
restorative, and pectoral.--_Dose_, 10 to 30 gr., or more.
=Extract of Box.= _Syn._ EXTRACTUM BUXI, E. CORTICIS B., L. _Prep._ (P.
Cod.) From the tincture of the root bark, prepared (with proof spirit) by
displacement, as EXTRACT OF ACONITE--P. Cod.
=Extract of Broom.= _Syn._ EXTRACT OF BROOM TOPS; EXTRACTUM SCOPARII, E.
SPARTII SCOPARII, L. From decoction of broom tops. Diuretic and cathartic;
and, occasionally, emetic.--_Dose_, 20 gr. to 1 dr.; in dropsy, &c. It is
now seldom used.
=Extract of Bry'ony.= _Syn._ EXTRACTUM BRYONIÆ, E. B. ALBÆ, E. RADICIS B.
A., L. _Prep._ From the infusion or decoction of the root of white bryony
(_Bryonia dioica_). Purgative, diuretic, and emmenagogue.--_Dose_, 10 gr.
to 1/2 dr. It was once a favourite remedy in asthma, dropsy, epilepsy, &c.
=Extract of Bu'chu.= _Syn._ EXTRACTUM BUCHU, E. DIOSMÆ, L. _Prep._ 1. From
buchu leaves, as the last.
2. (Ethereo-alcoholic; E. B. ÆTHERO-ALCOHOLICUM, L.--W. Procter.) Buchu
(in coarse powder), 1 lb.; ether, 4 fl. oz.; alcohol (rectified spirit),
12 fl. oz.; percolate without digestion, adding dilute alcohol until a
pint of ethereo-alcoholic tincture is obtained, and suffer this to
evaporate spontaneously; treat the residue in the displacer with dilute
alcohol, till 2 pints are obtained; evaporate to a syrup, add the product
of the first tincture, mix, and complete the evaporation.--_Dose_, 5 to 10
gr.; in diseases of the urinary organs, &c.
3. (Fluid; E. B. FLUIDUM, L.--W. Procter.) Buchu leaves, 8 oz.; rectified
spirit, 16 fl. oz.; for a tincture by displacement, adding water, until 12
fl. oz. have passed through; allow this to evaporate spontaneously until
reduced to one half; next digest the mass in the percolator with cold
water, 1 pint, for 12 hours, express a pint, and evaporate this to 10 fl.
oz.; lastly, add the 6 fl. oz. of residual tincture, agitate together, and
in a few days filter, or decant the clear portion.--_Dose_, 1 to 2
teaspoonfuls. See DIOSMA.
=Extract of Buck'bean.= _Syn._ EXTRACTUM MENYANTHIS, L. _Prep._ 1. (P.
Cod.) From the expressed juice of the fresh plant.
2. (Ph. Bor.) From the infusion made with boiling water. Bitter, tonic and
astringent.--_Dose_, 5 to 10 gr. In large doses it is purgative,
cathartic, and even emetic.
=Extract of Buck'thorn.= Syn. EXTRACTUM RHAMNI, E. BACCARUM R., L. _Prep._
From the filtered expressed juice of buckthorn berries. Some persons allow
it first to run into a state of fermentation; but the quantity of the
product is thereby greatly lessened. Hydragogue and purgative.--_Dose_, 15
gr. to 1 dr., or more.
=Extract of Bur'dock.= _Syn._ EXTRACTUM BARDANÆ, L. _Prep._ 1. From the
decoction of burdock root.
2. (P. Cod.) As EXTRACT OF BISTORT--P. Cod. In gout, rheumatism, skin
diseases, &c.--_Dose_, 10 gr. to 1 dr. Sir Robert Walpole praised burdock
root as a gout medicine; and others have considered it an excellent
substitute for sarsaparilla. (Lindley.)
=Extract of Butter-nut.= _Syn._ EXTRACTUM JUGLANDIS, L. _Prep._ (Ph. U.
S.) From the inner bark of the root of the butter-nut or white walnut
(_Juglanda alba_), as EXTRACT OF BITTER SWEET--Ph. U. S. A mild, yet
efficacious aperient and vermifuge.--_Dose._ As a laxative, 5 to 10 gr.;
as a purgative, 15 to 30 gr.
=Extract of Cainca Root.= _Syn._ EXTRACTUM CAINCÆ. (P. Pharm.) _Prep._
Put 10 oz. of the dried root of cainca into a percolator, pour on it proof
spirit q. s. to penetrate the powder in every part, and let it remain 12
hours; then let the liquid drain, and pass successively through the powder
in the percolator as much proof spirit as will amount with that previously
used to 60 oz. by weight. Distil off the spirit and evaporate to a soft
extract.
=Extract of Calabar Bean.= _Syn._ EXTRACTUM PHYSOSTIGMATIS. (B. P.)
Calabar bean in coarse powder, 1; rectified spirit, 5; macerate the bean
for 48 hours in one fourth of the spirit in a closed vessel, agitating
occasionally, then transfer to a percolator, and when the fluid ceases to
pass add the remainder of the spirit, so that it may slowly penetrate
through the powder; subject the residue of the bean to pressure, adding
the pressed liquid to the product of the percolation; distil off the
spirit, and evaporate what is left to the consistence of a soft extract by
a water bath.--_Dose_, 1/16 to 1/4 gr.
=Extract of Calum'ba.= _Syn._ EXTRACTUM CALUMBÆ, E. RADICIS C., L. _Prep._
1. (B. P.) Calumba cut small, 1; water, 5; macerate in half the water for
12 hours, strain, and press; macerate again with the remaining water,
strain, and press; mix and filter the liquors, and evaporate with the heat
of a water bath to pill consistency.--_Dose_, 2 to 10 gr.
2. (Alcoholic--Ph. Bor.) Nearly as No. 3 (_below_), but using stronger
spirit; the evaporation is to be conducted at a heat not above 167° Fahr.,
until it acquires the consistence of a pill-mass, which, after being
rendered quite dry by a very gentle heat, is to be reduced to fine powder.
It should have a brownish-yellow colour, and give a turbid solution with
water.--_Dose_, 4 to 12 gr. They are all tonic and stomachic.
3. (Spirituous--P. Cod.) As EXTRACT OF BOX. The Ph. Baden orders spirit of
·944 to be used.--_Dose_, 5 to 15 gr.
=Extract of Cannabis Indicæ.= See EXTRACT OF INDIAN HEMP.
=Extract of Canthar'ides.= _Syn._ EXTRACT OF SPANISH FLIES; EXTRACTUM
CANTHARIDES, E. LYTTÆ, L. _Prep._ 1. (P. Cod.) From the tincture, as
EXTRACT OF BOX.
2. (Soubeiran.) From a tincture prepared with spirit of the sp. gr. ·923
(about 2 u. p.).
3. (Acetic; E. C. ACETICUM, L.) From a tincture prepared with acetic acid,
sp. gr. 1·048.