C FI E M I 
been quite coagulated, it keeps fiveet the longer; in the 
contrary cafe it quickly becomes four. With a heat Ibme- 
what (l.ronger, on a water-bath, in a matrafs, it becomes 
like folid pap, or thick milk : this, with the addition of 
fugar, orange-flower, almonds, and cinsmon, forms 
an extraft known by the name of franchipane. This ex- 
trabl, expofeci to a naked fire in a retort, affords a fat 
oil, with a fqiid odour, carbonated hydrogen, and car¬ 
bonic acid gas ; the refiduary coal contains, carbonats of 
potafh and loda,muriatofpotafb,and calcareous phofphat. 
Milk, expoled to the air in wide open veflels, in order 
to prefent a, large furface, becomes covered with cream, 
or the butyrous matter, from which butter is made: in 
this cafe the milk rifes, which proves that it abforbs oxy¬ 
gen from the air. But, if left too long in contaft with 
air, the furface grows yellow and oily, the interior part 
becomes four, and little flocks are leen to float in it. 
Milk is capable of the vinous fermentation. Put it 
into an open cafk, agitate it frequently, and it will fer¬ 
ment, grow four, and increafe in bulk; there is a dil- 
engagement of carbonic acid gas, and a vinous liquor is 
produced. This is the mode ufed by the Tartars to pre¬ 
pare wine from mare’s milk; but it is laid they add a fa¬ 
rinaceous matter to affift the fermentation. 
Several gales unite with milk, and coagulate it; as 
fulphurated hydrogen gas, carbonated hydrogen gas, and 
carbonic acid gas. Milk, mixed with ten parts of water, 
cannot afterwards produce cheefe. Many Jubilances have 
the property of coagulating milk, though they be not 
acid; as, the plant called curdlemilk, artichoke-flowers, 
Spanilh thillle, fugar, extrafls, gums, the inner part of 
a fowl’s gizzard, animal gelatin, fifli-glue, hart’s-horn, 
See. Acids produce the ferae eftedls on milk; they im¬ 
mediately coagulate it 
According to Scheele, if a little alcohol be mixed with 
milk, and the mixture be expofed to heat in clofe veflels, 
care being taken to let out occafionally the gas which 
arifes during the fermentation, in a month’s time the 
whey will be found converted into vinegar. 
Rennet, or the curdled milk found in the ftomachs of 
calves, is much uled, efpecially in the making of cheefe. 
By means of this alio is prepared what is called <whey. 
Put a pint of milk into a lilver or earthen veflel over hot 
allies, and add two grains by weight of the rennet, diluted 
in a little water : as the milk heats, it curdles, and the 
whey or ferous part Separates from the white or cafeous 
part. When tbefe parts appear diftincl:, pour the whole 
Into a cloth : the whey pall’es through into the veflel be¬ 
neath, and the curd remains, which is to be left to drain. 
The whey is always whiter, if it contains a fmall part of 
the caleous matter much divided; but it may be feparated, 
fo that the whey remains limpid or colourlefs; this is 
called clarifying. Put into a veflel fome white of egg, a 
little of the ierum, or whey, and a few grains of tartar- 
ous acidule in powder; ftir or whip this mixture with 
ofier-twigs ; then add the reft of the whey, and place 
the whole once more on the fire, till it begins to bubble 
up. The tartareous acidule completes the coagulation 
of the remaining white part of the milk ; the white of 
egg hardens by boiling, and enclofes the caleous part. 
When the whey is clear, filter it through blotting-paper; 
the ftrained liquor is perfedlly limpid, and of a green- 
ilh call; this is clarified nxikey. 
Whey has a mild Iweetilh tafte ; it turns fyrup of vio¬ 
lets green. In a gentle heat, it gives out water in the 
proportion of about a feventh or eighth part. It Hill re¬ 
tains an animal fubftance like little flocks, becoming fetid 
in time ; this is albumen. Whey may be evaporated to the 
confidence ol honey ; after which it is put into moulds, 
and dried in the fun. This is the fugar of milk in cakes ; 
and is diliolved in water, clarified with whites of eggs, 
evaporated to the confidence of fyrup, and cryftallized in 
the cold. By this treatment it affords white cryllals in rliom- 
boidal parallelipipedons ; the mother water depofits yel¬ 
low and brown cryllals, which are purified by fuccelfive 
s T R Y. 359 
dilutions. Lichtenftein has examined and analyzed the 
different fugars of milk, which are fold at various prices 
in Swifleriand, and has more particularly diilinguilhed, 
i. The lweet fugar of milk, which is of a white colour, 
obtained from lweet and purified whey. 2. The acefcent 
fugar of milk, obtained from four whey. 3. The fugar 
of milk rendered impure by fat fubftances; which fepa- 
rate, according to him, in the fiift cryftallization. 4.. Su¬ 
gar of milk, mixed with oil and common fait, which 
cryftallizes the lad. 5. Sugar of milk, mixed with fat 
matter, common lalt and fal-ammoniac. It is adliefive 
and moift, and affords ammoniac on the addition of fixed 
alkali. 6. Sugar of milk, mixed with all the before- 
mentioned fubftances, and .likewife with extractive and 
cafeous matter. This lalt is of the confidence of honey, 
become rancid, and is acrid and difagreeable. 
Sugar of milk, when very pure, has a flightly faccha- 
rine, faint, and, as it were, earthy tafte; it always lofes 
by fucceflive dilutions. It is foluble in three or four parts 
of boiling water; and, according to Scheele, Rouelle, and 
Vulgamoz, it affords the fame products as fugar by dif- 
tillation. Rouelle obtained from a pound of this fait, 
by burning it, twenty-four or thirty grains of afhes ; 
three-fourths of which were muriat of potafh, and one- 
fourth carbonat of potafh. On a red-hot coal, fugar of 
milk melts, boils up, emits an odour of caramel, and 
burns like fugar. Thefe properties appear to indicate, 
that this fait is capable of affording the oxalic, like fugar 
by the nitric acid ; and Scheele has fhown, by his experi¬ 
ments, that it does : but he obferved, that four parts of 
Ipirit of nitre is required for this purpofe ; that four 
ounces of fugar of milk affords five grains of oxalic acid; 
and he has alfo difeovered, that if the refidues of fugar 
of milk be treated by the nitric acid, and filtrated, in 
Order to cryftallize the oxalic acid by evaporation, a white 
powder remains on the filter, which he found to be a pe¬ 
culiar acid, we give it the name of faccholaftic. He ob¬ 
ferved, that it poflefles the following properties. . It has 
the form of a white granulated powder ; two drachms of 
this fait, very pure, being heated in a glafs retort, melted, 
fwelled.up, and became black ; a brown fait, of a mixed 
fmell of benzoin and amber, fublimed, weighing thirty- 
five grains; this fait was acid, foluble in alcohol, more 
difficultly in water, and burned on charcoal. The re¬ 
ceiver contained a liquor of a brown colour, and not of 
an oily nature; eleven grains of charcoal remained in the 
retort. Carbonic acid and hydrogen gas were difengaged 
during this dillillation. The laccholadtic acid is very 
fparingly foluble in water, one ounce of boiling water 
diflolving only fix grains; one fourth of which was pre¬ 
cipitated by cooling. According to Morveau, this acid 
efiervefees with the hot folution of carbonat of potalh. 
The faccholaftat of potafii was obtained, by cooling,, 
which was foluble it eight times its weight of hot water, 
and cryftallized again by cooling. The fait is formed 
with the foda was cryllallizab-le, but required no more 
than five parts of water for its folution. This acid com¬ 
bines likewife with ammoniac ; the neutral fait, thus pro¬ 
duced, lofes its alkali by heat. With barytes, alumine, 
magnefia, and lime, it forms falts nearly infoluble. It 
a< 5 ls but very feebly on the metals, and forms with their 
oxyds falts of difficult folubility. It precipitates the ni- 
trats of mercury, lead, and lilver, as well as the muriat 
of lead. Scheele, when he firl’t made this difcovery, fup- 
pofed that the white powder, depofited by the oxalic acid 
obtained from fugar of milk by means of the nitric acid, 
was merely a portion of the calcareous oxalat formed of 
the lime, which might be contained in that animal fait. 
But he was foon undeceived, by pouring a fmall quantity 
of pure oxalic acid into a folution of fugar of milk, as 
the mixture afforded no precipitate. Weverthelels, Herm- 
ftadf, who has pubiilhed two memoirs in Creil’s Chemi¬ 
cal Journal, the lecond of which treats particularly of 
this acid earth, thinks, notwithftanding the experiments 
of Scheele, that it is a compound of oxalic acid, lime, 
and 
