38 ORGANIC CONSTITUENTS. 



cnrj, and neutral acetate of lead do not influence its solution; 

 it isj however, precipitated by basic acetate of lead. 



Extractive matter of milk. For tlie purpose of investi- 

 gating the properties of tins substance, Simon evaporated a 

 quart of woman's milk (partly colostrum and partly during tlie 

 early weeks of lactation) to about eight ounces, and he then 

 removed the casein and butter by the addition of alcohol. After 

 filtration, some w ater was added ; the fluid was again evapo- 

 rated to a residue of a few ounces, treated with alcohol of -833, 

 and allowed to rest for some time. Sugar of milk of a slightly 

 yellow colour was deposited, and the supernatant fluid had 

 nearly the same tint. The latter was evaporated on the water- 

 bath to the consistence of a syrup, and then treated with 

 anhydrous alcohol, which reduced nearly the whole syrup to a 

 solid consistence, while the alcohol above it, which contained the 

 alcohol- extract, was hardly tinged yellow. The precipitate wliich 

 is thrown do^vn by the anhydrous alcohol contains the spirit- 

 extract, and the water-extract is contained in the yellow-coloured 

 sugar of milk. 



The ivater-ewtract of milk is obtained by treating the pre- 

 cipitated sugar of milk with water, and allowing it to stand, 

 well covered, for some days. In this manner we obtain a yellow, 

 almost clear, and viscid fluid, standing above the white sugar 

 of milk. On remo\dng this fluid, and alloAv^ng it to evaporate 

 spontaneously, a fresh quantity of sugar of milk is deposited ; 

 in fact, it appears impossible to remove all traces of this consti- 

 tuent of the milk from the water-extract. Alcohol throws down 

 a yellow, glutinous, tough extract, which exhibits a feeble 

 alkaline reaction towards litmus paper. This is the water- 

 extract. Wlien burned, it leaves a porous coal, from wliich a 

 white alkaline ash, containing carbonates, may be obtained 

 without much difficulty. 



It is precipitated from its solution by infusion of galls, basic 

 and neutral acetates of lead, but not by bichloride of mercmy. 



The S2)irit-extract of milk is obtained from the precipi- 

 tate which was tlu-own down by the anhydrous alcohol; it 

 must be dissolved in a little water, and treated with alcohol of 

 '833, which usually causes the separation of a little sugar of 

 milk. The spirituous solution must now be evaporated to a very 

 small residue, and some distilled water added, which produces 



