C H E M 
marrow, contained in long bones, exhibits the fame pro¬ 
perties as fat; but the comparative analyfis has not been 
yet made with fufficient accuracy to defcribe its charac- 
teriftic properties. 
Of URINE. 
Margraaf is the firft who made an accurate analyfis of 
urine; this was in 1737. He difcovered therein feveral 
phofphoric falts. Rouelle the elder has given four excel¬ 
lent papers on the fame fubjeCl. Scheele difcovered the 
matter which forms calculus. Berthollet difcovered 
naked phofphoric acid. 
Urine is a faltifh liquor, regarded as an animal lixi¬ 
vium. There are two forts of urine, the firft called crude 
urine , when emitted a fhort time after meals, is clear, 
and almoll deftitute of talfe and l'mell; it contains a 
much l'nialler proportion of the principles than the other, 
■which is called urine of the blood, or urine of concoc¬ 
tion. This laft is not emitted till the procefs of digef- 
tion is finifhed, and if is feparated from the blood by 
the kidneys ; while the former appears to be filtrated, in 
part, from the ftomach and inteftmes immediately to the 
the bladder, by means of the cellular membrane, or by 
the abforbent veflels. Many foods are capable of com¬ 
municating certain peculiar properties to urine. Tur¬ 
pentine produces a fmell of violets, and afparagus a very 
fetid fmell, in this fluid. Such perfons as have weak fto- 
machs, void urine, which retains the fmell of filch foods 
as they have taken. 
Urine reddens tinflure of turnfole ; its heat is from 30 
to 32°. In a cold temperature, it fooner grows turbid, 
and makes a depofit. If the temperature is from fixteen 
to 18°, the urine, being deprived of 12 0 , does not 
grow thick, as in winter. Expoled to 6° below zero, a 
part freezes; but this is not fait; it is fcarcely any thing 
but water; the other partis more condenfed, more eafily 
evaporated, more proper for the extraction of a number 
of falts. Left to become putrid, it firft lofes its natural 
fmell for an ammoniacal one, which pafies away in its 
turn ; its yellow colour is converted to a green, and then 
the fmell is fetid and naufeous. Putrefied urine exhibits 
more of the naked alkali than frelh urine. 
If urine be evaporated flowly, the firft cryftals which 
appear are earthy phoiphats, then nitric acid, phofphat of 
potafli, and muriat of foda. If urine be concentrated to 
the confidence of an extraCf, or of honey, and then mixed 
with muriat of lead and charcoal, phofphorus will be 
obtained. For this purpofe, mix muriat of lead (proceed¬ 
ing from the diltillation of four parts of minium with two 
of muriat of ammoniac) with fix parts of extract of urine; 
add one half part of charcoal in powder. Dry the mix¬ 
ture in an iron pot till brought to a black powder: put 
this powder into a retort, and draw from it the ammo¬ 
niac, a fetid oil, and the muriat of ammoniac ; the re- 
fidue contains the phofphorus. Try it by throwing a 
little upon burning coals: if it exhales a fmell of garlic 
and a phofphoric flame, put it into a good ftone retort, 
well luted. Place this in a reverberatory furnace, ter¬ 
minated with a pipe or chimney 5 adapt to the retort a 
a balloon or receiver half full of water ; lute the joinings 
exaClly, and proceed to diltillation with a gradual heat. 
The phofphorus thus obtained may be purified by a le- 
cond diltillation. In this operation, the muriat of lead 
decompofes the phofphat of foda contained in the extract 
of urine, forms a phofphat of lead which affords phoi- 
phorus, while the phofphat of foda is indecompolable by 
the charcoal. 
The analyfis of urine has been made by feveral che- 
mifts, as may be l'een in moll elementary treatiles : but 
a more extenfive and accurate analyfis has lately been 
accompliftied by Fourcroy and Vauquelin, not only on 
urine, but on urinary calculi. Many valuable papers on 
this fubjeCt, have been recently prefented to the public 
both in England and France; and La Grange has given 
Von. IV. No. t,q 3. 
S T R Y. 36s 
a fuccinCt account of molt of their contents, in his Court 
de Cbimie. 
Urine, by a gentle heat, is brought to the confiftencd 
of honey: this is to be treated with very pure alcohol, 
which diffolves, 1. A particular fubftance called urinous 
matter. 2. Muriat of ammoniac. 3. Muriat of foda. The 
other falts are not foluble by the alcohol. 
To feparate this urinous matter, evaporate the alcohol 
with a gentle heat, or diltil in a retort that the product 
may not be loft; dilute the reiidue with water, till it is 
of the confidence of a thin fyrup; then pour in nitric 
acid, and a plentiful precipitate will be depofited, which 
is the combination of this urinous matter with the nitric 
acid. The muriats of ammoniac and of foda remain in 
folution in the liquor, falted by a portion of the urinous 
matter. To have the urinous matter pure, diflolve in 
water the precipitate formed by the nitric acid ; add pot- 
a(h to faturate the nitric acid it is joined with. Then 
evaporate to the confidence of honey, and treat afrefh 
with alcohol, which attacks the urinous matter, while 
the nitrat of potafli which is formed remains infoluble. 
Separate this l’alt,. and diltil with a very gentle heat to 
colleCt the alcohol. A yellowifh fubftance remains in 
the retort, hitherto unknown, with new and peculiar 
characters. This is what thefe chemilts regard as the 
urinous matter, or that which gives to urine its charac- 
teriftic properties, as fmell, tafte, &c. By diflblving tins' 
in water, an artificial urine may be formed, of a deeper 
or lighter colour, according to the quantity of water 
ufed. This fubftance affords cryftals with the nitric 
acid. Diddled over a naked fire, it is almoft entirely 
converted into carbonat of ammoniac ; it gives fcarcely 
any oil, and very little coal remains in the retort. It 
unites with many faline fubftances, and modifies or in¬ 
verts their form of cryitallization ; the muriat of ammo¬ 
niac palling from the oCtahedron to the cube, and the 
muriat of foda from the cube to the octahedron. P'our- 
croy and Vauquelin propofe to examine farther into this 
matter, as it affords au inftance unexampled in its kind. 
The falts not foluble in alcohol, are, phofphats of mag- 
nefia, lime, and foda, uric and benzoic acids, and albu¬ 
men. To feparate thefe falts, pour them into hot water, 
to cryftallize fuch as are fufceptible of it, and their crys¬ 
tals will be obtained feparately. But the phofphats of 
lime and of magnefia, and the uric acid, cannot be dif- 
folved by the water. To feparate the uric acid from 
thefe laft falts, add potafn, which attacks the uric acid, 
and decompofes the phofphat of magnefia at the fame 
time. Thus you have an urat of potafh, and a phofphat 
ofpotafh; the magnefia remains with the phofphat of 
lime. The urat of potafli may be decompoied by help 
of the muriatic acid, which feizes on the potafli; dif- 
folve the uric acid in water, and it will crylcailize On 
the other hand, the phofphoric acid is to be attacked 
with lime, which forms an infoluble fait. To feparate 
the magnefia from the phofphat of lime of the firft expe¬ 
riment, add fome acetous acid, which forms a foluble lalt 
with magnefia, and the phofphat of lime remains pure. 
Thele experiments prove, that ten diltinCt iubftances 
may be obtained from urine: 1. Muriat of foda, wdiich 
in urine that has been evaporated, cryftallizes in oCtahe- 
drons. 2. Muriat of ammoniac, the natural octahedral 
form of which is changed into the cube, by its combina¬ 
tion with the urinary matter, in the fame manner as the 
muriat of foda is changed by this combination from the 
cube to the oCtahedron. 3. The acid pholphat of lime, 
which forms about one-feven hundiedth part of the urine. 
It is precipitated by alkalis, which take from it the ex r 
cefs of acid. 4. Phofphat of magnefia decompofed by 
alkalis, and giving its earth mixed with the phoiphat of 
lime, which is depofited, becoming'a triple lalt, its cryf¬ 
tals l'eparating by the lpontaneous formation of the am¬ 
moniac. 5. Phofphat of loda, efflorefcing in the air, al¬ 
ways united with phofphat of ammoniac. 6. Phofphat 
5 A of 
