Primary Cleavage Products. 385 
considerable acetic acid with such a large percentage of adherent 
mineral matter, unless the latter is chemically combined with the 
albuminous substance. Oft-repeated and long continued dialysis 
appears to have but little influence in diminishing the amount of this 
impurity. Our experience has taught us that where the caseoses 
have once been brought in contact with lime salts, reprecipitation 
and other methods of purification avail but little. 
But very little heterocaseose was found in this digestion, not as 
much as was found in some of the others, later on. Still, during the 
first dialysis of the protocaseose, some little heterocaseose separated 
from the fluid, as the last traces of salt dialyzed out. 
A. Deuterocaseose. 
Deuterocaseose was separated from the filtrate from the first sodium 
chloride precipitate of protocaseose, by acetic acid. Asastudy of the 
reactions of protocaseose had shown plainly that this body is never 
completely precipitated by salt alone, a little acetic acid was added 
to the salt-saturated filtrate, and the precipitate, presumably a mix- 
ture of proto and deuterocaseose, thrown away. The remaining deu- 
terocaseose was then precipitated by adding about 200 c.c. of a salt- 
saturated acetic acid (30 per cent. acetic acid) to the fluid. The total 
volume of the mixture was nearly 16 litres. In this manner an abund- 
ance of a finely divided precipitate was obtained, which at first, seemed 
insoluble in water and in dilute sodium chloride. It was readily soluble 
in water containing a trace of alkali and was not precipitated by 
neutralization. On being washed, however, with a saturated salt 
solution for some time, the washings were found to have dissolved 
considerable of the substance, which could be precipitated from the 
solution by strong acetic acid. Further, after being washed with 
salt solution, the substance remaining appeared quite noticeably solu- 
ble in water. Evidently then, this body on being washed more 
or less free from acid, becomes soluble in water to a certain extent, 
its aqueous solution then giving a strong reaction with acetic acid 
and potassium ferrocyanide. The great bulk of the precipitate was 
therefore washed with saturated salt solution until the washings were 
nearly free from acid; then, having become partially soluble in water, 
it was placed in about 2 litres of water, the solution ultimately 
saturated with sodium chloride and the caseose again precipitated 
by addition of about 20 ¢.c. of acetic acid. This second precipi- 
tate was washed somewhat with salt solution and finally with a 
large volume of water. At first, the washings gave no reaction with 
Trans. Conn. Acap., VoL. VII. 49 Nov., 1886. 
