BY R. GREIG SMITH. 141 



baryta waters; this is insoluble in lime water. The colour re- 

 actions of the albumens, which are generally decided in the case 

 of the included mucins, are not so with this substance. Finally, 

 the nitrogen percentage shows that it is neither a mucin nor an 

 allied substance. 



In the estimation of the nitrogen the clear aqueous solution 

 was precipitated with alcohol and redissolved in water several 

 times until an opalescent alcoholic solution was obtained. This 

 was divided into two parts, one of which was precipitated with 

 common salt, the other with barium chloride. The precipitates 

 were then washed with alcohol and dried until they ceased to 

 lose weight. Portions were taken for the ash determination and 

 for the nitrogen, which was estimated by the Kjeldahl process,, 

 due allowance being made for the nitrogen in the sulphuric acid,, 

 etc., by check tests with pure saccharose. 



Portion precipitated by common salt : — 



0-1542 grm. gave 0-0128 grm. ash = 8-30%. 



The ash consisted of carbonate, phosphate, sulphate, 



and chloride of soda. 

 0-2164 grm. required 0-5 c.c. ^/o acid to neutralise the 



ammonia .-1-76% nitrogen in the ash-free substance. 

 Portion precipitated b}' barium chloride : — 



0-1054 grm. gave 0*0184 grm. ash= 17*47%. 



The ash consisted of carbonate, phosphate, sulphate, 



and chloride of barium. 

 0-1820 grm. required 0-25 c.c. ^/.^ acid to neutralise the 



ammonia = 1"16% nitrogen in ash-free substance. 



The amount of dry gum in the cultures is very small — a ver}^ 

 viscous solution contains very little solid gum, and on this account 

 only a small quantity was available for the determination. But 

 although these results differ from one another, still they are 

 sufficient to show that the nitrogen in the dry and ash-free slime 

 is less than 2%. This indicates that it is far removed from mucin, 

 which contains about 12%, from pseudomucin with about 10%, 

 and from colloid with about 7%. The presence of phosphoric acid 



