1887.] 



On Kreatinins. 



367 



some days, the total precipitate was collected, washed with cold water, 

 dried in a vacuum over H 2 S0 4 , and weighed. 



(I.) 34,640 c.c. of urine gave 198 grams of Hg salt, equivalent to 

 5' 7 grams of Hg salt per litre of urine. 



(II.) 40,625 c.c. of urine gave 293T3 grams of Hg salt, equivalent 

 to 7*19 grams of Hg salt per litre of urine. 



The mean specific gravity in Experiment I was 1*020, and the 

 mean reduction of picric acid was equivalent to 0"67 grain glucose per 

 1 fluid ounce. 



The mean specific gravity in Experiment II was 1*022, and the 

 mean reduction of picric acid was equivalent to 0*86 grain of glucose 

 per 1 fluid ounce. 



In my own case I found that the mean quantity of mercury salt 

 obtained from the urine of twenty-four hours agreed very nearly with 

 the above results, the total urine of six days having been carefully 

 collected and examined each twenty-four hours. 



The formula of the spherical mercury salt arrived at by analysis 

 is 4(C 4 H 7 N 3 O.HCl.HgO).3HgCl 2 . 



It may here be observed that mercuric chloride has been recom 

 mended by Maly (' Ann. Chem. Pharm.,' vol. 159, p. 279) for preparing 

 kreatinin from the urine of man or the horse. He does not mention 

 the fractional precipitation by mercuric chloride, but recommends a 

 preliminary concentration of the urine by heat, and precipitation by 

 basic lead acetate before adding mercuric chloride. On repeating his 

 process I found that even after the removal of the uric acid, &c, by 

 basic lead acetate, the mercuric chloride still produced an immediate 

 flocculent precipitate, followed by a granular one, and if the flocculent 

 amorphous matter was not separated by filtration, the total mercury 

 precipitate yielded a gummy mass after treatment with H 2 S, which 

 would not yield crystals until treated with alcohol, as Maly himself 

 recommends. By my method, however, the hydrochloride of the 

 reducing base is obtained in crystals after the first evaporation ; these 

 crystals contain chlorine in the proportion required by the formula 

 C 4 H 7 N 3 0.HC1. 



The platinum salt of the reducing base is obtained in the form of 

 anhydrous crystals, when an alcoholic solution of its hydrochloride is 

 mixed with an alcoholic solution of platinic chloride. If these anhy- 

 drous crystals be dissolved in water, and the solution evaporated, or if 

 the aqueous solution of the hydrochloride of the base be mixed with 

 platinic chloride in aqueous solution and evaporated, fine orange- 

 coloured prisms separate out, which have the formula 



2(C 4 H 7 N 3 O.HCl).PtCl i .2H 2 0. 



Heated to 100° C, these crystals become anhydrous, yellow, and 

 opaque. 



VOL. xlii. 2 E 



