On Krcaiinins. 



511 



was decomposed by hydrogen sulphide in presence of water, special 

 care being taken to avoid too great a rise of temperature by constant 

 agitation in a closed bottle during the action of the gas upon the 

 precipitate. 



After the action was complete the solution was set aside for three 

 days in a tall glass cylinder, to allow the mercuric sulphide to 

 settle. As much, as possible of the clear and supernatant liquor 

 was then decanted off from the precipitate, and set to evaporate in 

 vacuo over sulphuric acid. Hard anhydrous crystals of kreatinin 

 hydrochloride resulted. After being washed with a little cold alcohol, 

 these crystals were dissolved in about fifteen times their weight of 

 cold water, the solution was well stirred with, pure lead hydrate, 

 and filtered. The filtrate when evaporated in vacuo over sulphuric 

 acid, deposited needle-shaped crystals of a base for which I propose 

 the name of efflorescent kreatinin, whose -properties and composition 

 will be described shortly. This efflorescent kreatinin, being obtained 

 from the spherical mercury salt of urine as far as possible without 

 any application of heat, I believe to be the true natural kreatinin of 

 urine. 



The washings from the lead oxy chloride, &c, after the above treat- 

 ment were evaporated at 60° C. on a copper plate kept hot by steam. 

 A number of anhydrous square tables were obtained on cooling; which 

 when dissolved in cold water yielded an alkaline solution which 

 deposited efflorescent kreatinin on evaporation in vacuo over sulphuric 

 acid. 



The third substance is obtained as follows : — 



The washings from the mercuric sulphide in the above experiment 

 were concentrated over steam. The concentrated liquor was diluted, 

 decolourised by animal charcoal, and filtered. The filtrate was again 

 concentrated over steam, and finally evaporated in vacuo over sul- 

 phuric acid. The resulting crystals of kreatinin hydrochloride did 

 not differ in outward appearance from those obtained from the solu- 

 tion to which no heat had been applied ; but, when decomposed by 

 pure lead hydrate after solution in fifteen parts of cold water — in 

 short, under conditions as nearly as possible identical with those 

 present in the case of the hydrochloride crystallised from cold 

 aqueous solution — instead of efflorescent kreatinin, anhydrous square 

 or oblong tabular crystals are obtained, similar in form to the tabular 

 crystals resulting from the evaporation of an aqueous solution of the 

 efflorescent kreatinin of urine at 60° C, but more transparent than 

 the latter, and differing from them in that their cold aqueous solution 

 deposits anhydrous tabular crystals again on spontaneous evaporation, 

 instead of efflorescent crystals. 



This tabular anhydrous kreatinin, which re-crystallises unaltered 

 from its cold aqueous solution on evaporation in vacuo over sulphuric 



