THE VOLATILE PART OF PLANTS, 93 
According to Hoppe-Seyler, (Med. Chem. Unters., I,) the phosphorized 
principle of oil of maize, and of the brain, nerves, yolk of eggs, ete., is 
primarily the substance discovered in 1864 by Liebreich, in the brain, 
and termed Protagon. It isa white crystallized body, having the 
following composition : ; 
Carbon, 67.2 
Hydrogen, 116 
Nitrogen, 2.7 
Phosphorus, 1.5 
Oxygen, 17.0 
100.0 
Its formula is Cy16, Hos, Ng, P, Oo2. When heated to the boiling point 
it is decomposed, and yields among other products glycerin, phosphor- 
ic acid, and stearic acid. (Ann. Ch. Ph., 134, p. 30), 
Saponification.—The fats are characterized by forming 
soaps when heated with strong potash or soda-lye. They 
are by this means.decomposed, and give rise to fatty 
acids, which remain combined with the alkalies, and, to 
glycerin, a kind of liquid sugar. 
Exp. 41.—Heat a bit of tallow with strong solution of caustic potash 
until it completely disappears, and a soap, soluble in water, is obtained. 
To one-half the hot solution of soap, add chlorhydric, acid “until the 
latter predominates. ‘An oil will separate which gathers at the top of 
the liquid, and on cooling, solidifies toacake. This is not, however, 
the original fut. It has a different melting point, and a different chemi- 
eal composition. It is composed of one or several fatty acids, corre- 
sponding to the elementary fats from which it was produced. 
When saponified by the action of potash, stearm yields 
stearic acid, C,, H,,O0,; palmitin yields palmitic acid, 
C,, H,,O,; and olein gives oleic acid, C,, H,, 0,. The 
so-called stearin candles are a mixture of « stearic and 
palmitic acids. The glycerin, C, H,-O,, that is simulta- 
neously produced, remains dissolved in the liquid. Glyce- 
rin is now found in commerce in a nearly pure state, as a 
colorless, syrupy liquid, having a pleasant sweet taste. 
The chemical act of saponification consists in the re-arrangement 
of the elements of one molecule of fat and three molecules of water ine 
to three molecules of fatty acid, and one molecule of glycerin. 
Palmitin Water. Palmitic acid. Glycersn, 
On Hee Os + 3(H2 0) — 3 (Cie Hea On) + Cy Hy Op 
