M i L K. 
377 
®f milk, fomewhat of tlVe fame kind might have appeared; 
and thei'e fubftances, which in their natural date were not 
fo, might appear very infoluble. However, we may allow 
that milk is always fomehow infoluble in the inteftines, as 
it is of a drying nature, and as cheefe, &c. is very coftive. 
And this effedt Ihows that milk is always coagulated in 
the ftomach ; for, if it remained fluid, no faeces would be 
produced, whereas fometimes very hard ones are obferved. 
In the blood-vefl'els, from its animal nature, it may be 
confidered as nutritious ; but, when we confider its vege¬ 
table contents, and acefcency in the primae vise, we find 
that, like animal food, it does not excite that degree of 
fever in the time of digeftion, and that from its acefcency 
it will refill; putrefaftion. Hence its ufe in liedtic fevers. 
There appears allb fomewhat peculiar to milk, which 
requires only a fmall exertion of the animal powers in 
order to its aflimilation ; and, befides, in hetftic complaints 
there is wanted an. oily bland food, approaching to the 
animal nature ; fo that on all thefe accounts milk is a diet 
peculiarly adapted to them, and, in general, to moft con- 
vaiefcents, and to thofe of inflammatory temperaments. 
So far of milk in general. We fliall now fpeak of the 
particular kinds which are in common ufe. 
The milk of different animals differs confiderably.— 
Women’s milk is much thinner than cows’ milk 5 is of a 
bluer colour, and contains more faccharine matter. It does 
not afford butter till fome time after delivery, although it 
contains fome oily matter. It contains lefs curd than the 
milk of the cow. The milk of women is liable to greater 
changes from difeafe than any other. Spafms, which are 
not uncommon to thole who fuckle, fo change the milk, 
as to be unpleafant and unwholefome to the infant. It is 
cfoferved by Deyeux and Parmentier, that, when the milk 
is drawn from the bread: at Ihort intervals, it is conftantly 
watery and poor, and is but of little fervice to the infant. 
They therefore recommend, that the intervals of fuckling 
fliould be as great as poflible, without inconvenience to 
the infant or the nurfe. 
The milk of the afs is alfo different from cow’s milk : 
it contains more faccharine matter, and, like women’s 
milk, is thinner than that of the cow. There is nothing 
in this milk more than in others, to warrant the medical 
qualities which fome afcribe to it. Afles’ milk is faid to 
be a great beautifier and prelerver of the Ikin. Poppasa, 
wife of the emperor Nero, ui'ed it for that purpole ; hav¬ 
ing four or five hundred afles conftantly in her retinue, 
to furnilh her every morning with a frefli bath. The re¬ 
ceipt for making what is called artificial afles’ milk is as 
follows: Be- Limac. terreft. contull xvni. Rafur. C. Cervi, 
Hordei perlati, Rad. eryngii, fing. unc. i. aquae purse lib. vi. 
coque leni igne in vale figulino vitriato ad lib. in. dein 
cola, et adde fyrup balfamici lelcunciam. Capiat teger 
mane et vefperi quotidie unc. vi. hujus liquoris miitas 
cum laftis vaccin. recentis p. se. Med. Tranf. vol. ii. p. 341. 
Goats’ milk is lomething thicker, and appears richer, 
than even the cows’ milk. It has a peculiar aroma, which, 
from the black goat, is fo ftrong as to be difagreeable. It 
affords butter and cheefe: the former is of a whiter co¬ 
lour than that from the cow, and is faid to keep longer. 
Ewes’ milk has the appearance of cows’ milk. It af¬ 
fords a much larger quantity of cream, forming a loft 
and very fuflble butter. Its cafeous matter is very loft 
and undtuous, and is fometimes mixed with that from 
the cow, to give it a rich appearance. 
Mares’ milk is the next to women’s milk in quantity 
of faccharine matter: it affords little cream ; and does not 
eafily coagulate. It is from the quantity of fugar con¬ 
tained Ire this milk, that it affords alcohol by fermentation. 
The fpecific gravity of milk, on the average, is about 
j - o35, water being 1. According to Brifion, whole au¬ 
thority on this phyfical property of bodies Hands high, 
the following are the fpecilic gravities of the milk of 
different animals : 
Women’s milk rozoj 
Cows’ - ro324 
Goats’ - - i'034i 
Vol. XV. No. xojo. 
Mares’ - - 
Afles’ - 
Ewes’- - - - 
i - o 346 
55 
i'0409 
It is not eafy to affign the difference between milk frefli 
drawn and that detained in the open air for fome time ; 
but certainly there is fome material one, otherwife nature 
univerlally would not have diredted infants to fucking ? 
and indeed it leems better than the other fitted for di¬ 
geftion and nourilhment. Phyiicians have fuppofed that 
this depended on the evaporation of fome fpt. retlor ; but 
thefe volatile parts can hardly be nutritious. A more 
plaufible account feems deducibie from mixture ; milk 
newly drawn has been but lately mixed, and is expofed 
to fpontaneous reparation, a circumftance hurtful to di¬ 
geftion ; none of the parts being, by themfelves, fo eafily 
aflimilated as when they are all taken together. Hence, 
then, milk newly drawn is more intimately blended, and 
therefore then is moft proper for the weakly and infants. 
Another difference in the ufe of milk expofed for fome 
time to the air, is taking it boiled or unboiled. Phyii- 
cians have generally recommended the former $ but the 
reafon is not eafily affigned. Perhaps it is this: Milk 
kept for fome, time expofed to the air has gone fo far to 
a fpontaneous feparation ; whereas the heat thoroughly 
blends the whole, and hence its refolution is not 1b eafy 
in the ftomach ; and thus boiled milk is more coftive than 
raw, and gives more feces. Again, When milk is boiled, 
a conliderable quantity of air is detached, as appears from 
the froth on the furface ; and air is the chief inftrument 
of fermentation in bodies ; 1b that after this procefs it is 
liable to acefcency ; for thefe realbns it is proper for the 
robuft and vigorous. Another difference of milk is, ac¬ 
cording as it is fluid or coagulated. The coagulated is of 
two kinds, as induced by rennet, or the natural acefcency 
of the milk. The former preparation makes the. firmer 
and lefs-eaiily foluble coagulum; though, when taken with 
the whey unfeparated, it is lefs difficult of Iblution, yet 
more 1b than any other coagulum in the fame cafe. Manv 
nations ufe the latter form, which is ealier foluble, but 
very much acefcent; and therefore, in point of iblution, 
fliould be confined to the vigorous ; in point of acefcency, 
to thole who live on alkalefcent food ; and,in the laft cafe, 
the Laplanders ufe it as their chief acefcent condiment. 
From the fame conliderations it is more cooling, and ia 
its other effedts like all other acefcent vegetables. 
Milk by evaporation yields a Iweet faline matter, of 
which Dr. Lewis gives the following proportion : 
T welve 
ounces of 
Left of dry 
matter 
From which water-extradfed 
a fweet faline fubftance 
amounting to 
Cows’ milk 
13 drachms. 
ii drachms. 
Goats’ milk 
- 
1 i- 
Human milk 
3 --a— 
6 
Afles’ milk 
8 
6 
The faline fubftance extracted from afles’ milk was white, 
and liveet as fugar ; thofe of the others brown or yellow, 
and confiderably lefs Iweet; that from cows’ milk had the 
leaf lweet’iels of any. The Iweet faccharine part of the 
milk remains diffolved in the whey after the reparation in 
the curd or cheefy matter, and may be colledted from it ia 
a white cryffalline form, by boiling the whey till all re¬ 
mains of the curdled fubftance have fallen to the bottom ; 
then filtering, evaporating it to a due confidence, letting 
it to lhoot, and purifying the cryftais by foLution in water 
and a lecond cryftallization. Much has been liud of the 
medicinal virtues of this fugar of milk, but it does not 
feeni to have any confiderable ones., It is from cows’ milk 
that it has been generally prepared ; and the cryftais ob¬ 
tained from this kind of milk have but little Iweet nets. 
Different methods have been' prop.oled for obtaining 
the fugar of rnifk. The following is an account of a me¬ 
thod ufed by fome of the Tartar nations of prelervin.^ 
their’miik by means of froit; in which operation great 
quantities of the fugar of milk are accidentally formed. 
The account was given by Mr. Fahrig of Peterlburgh, who 
undertook a journey, by order of the Academy of Peterf- 
burgh, among tiie Mogul tribes who inhabit the country 
beyond the lake Baikal, on the banks of the riyerSalensra. 
5 0 ' Thefe 
