BACTERIAL CELLULAR SUBSTANCE 75 



of the existence of lysin. She says: "As to lysin, I have 

 obtained in every instance a yellow, thick, oily body, where 

 lysin picrate should be formed, which, however, could not 

 be crystallized. This oily body was shaken up with ether 

 to remove excess of picric acid, but when I attempted to 

 purify it by redissolving it in alcohol, it was no longer 

 completely soluble, inasmuch as a part of it hardened into 

 a solid which seemed somewhat crystalline, and the remainder 

 was precipitated by alcohol. However, it was found to be 

 readily soluble in water, especially in hot water, and although 

 no crystals were obtained, on concentration of the aqueous 

 solution, the same heavy oil separated. In order to obtain 

 the hydrochloride, if possible, the oily substance was treated 

 with hydrochloric acid in a little water, and the picric 

 acid shaken out with ether. From the solution on concen- 

 tration an imperfectly crystalline mass was obtained. It 

 may be that I have not lysin, but there is undoubtedly 

 present some organic body which, in its chemical behavior 

 at least, is very similar to lysin." 



In searching for the hexon bases in the cellular substance, 

 Leach proceeded as follows : " The cell substance was stirred 

 with nine times its weight of 33.33 per cent, sulphuric 

 acid, allowed to stand overnight, then heated in an evapor- 

 ating dish on the water-bath. When all danger of frothing 

 was over, the mixture was transferred to a flask fitted with a 

 reflux condenser, and boiled on a sand-bath for eight hours 

 one day and six the next. After cooling and filtering, some 

 water was added to the filtrate, and it was neutralized by 

 the addition of the calculated amount of barium hydrate. 

 When the barium sulphate had completely settled, the 

 supernatant liquid was siphoned off, the precipitate stirred 

 up with boiling water, heated to boiling, settled overnight, 

 and again siphoned. This was repeated until the wash 

 water was nearly colorless. The extract and wash water 

 were united, acidified with acetic acid, 1 concentrated on 



1 If there is a large excess of barium present, it is well to remove it by 

 carbon dioxide. 



