Memoir upon Anintal Fat. 79 
fat, does not completely take off its acidity ; it rather dis- 
solves it for the most part, and this last liquor is still 
acid. | 
Since the acid adheres so intimately to the fat, I tried to 
separate it from the latter by-salifiable bases, and I made use 
of lime-water, which I boiled with oxygenated fat; the fat 
Jost its alkalinity, and acquired a colour of a citron yellow. 
This neutral liqnor, which I regarded more as a combina- 
tion of lime with an aeid, than fat, was abundantly preci- 
pitated by the acetate of lead. ; 
Evaporated to the consistence of a syrup, it is discoloured 
by the nitric and muriatic acids, which form in it a whitish . 
precipitate; at the same time, when we pour the acid, a very 
rancid odour is manifested. 
Barytes water acts upon oxygenated fat in a more effica~ 
cious manner. The orange yellow colour which the water - 
acquires from it is equally destroyed by the acids. I poured 
into it a quantity of sulphuric acid sufficient to carry off the 
barytes ; I boiled the whole, and I filtered the liquor while 
boiling. 
The filtered liquor, which contained no barytes, was in a 
great measure evaporated in a sand-bath ; small fine needles 
were crystallized mixed with silky tufts, not precipitable by 
lime water, insoluble in alcohol, and which were not sub- 
limed in close vessels. 
When fat is boiled with concentrated nitric acid, and the 
ebullition is continued, adding water from time to time, a - 
white crystalline powder is formed upon cooling. 
This substance is rough to the touch, insoluble in alcohol, 
much more soluble in boiling water than in cold water. By 
its combination with the bases, and by several other charac- 
ters, I was convinced that it was mucous acid*. 
Fat thus oxygenated at the maximum is soft, of a brown 
colour, sensibly soluble in water, and very soluble in alco- 
hol. Its washing was saturated by potash; from this re- 
sulted a leafy salt, attracting humidity from the air, and 
* Beef suet, although it decomposes less strongly the nitric acid, also yields 
mucous acid. r 
which 
