532 DR. AV. 0. MOOR, 



hoiirs by 1,5 gr. ureine, we proceed in the following mauuer: We evapo- 

 rate lOOcbcm. of urine at a température of about 45 — 50° C. until a gelé- 

 lïke, half solid residue remains, wliich caunot be poured from one récipient 

 into another; care must be taken to avoid overheatiug of the urine towards 

 the end of the evaporation^). The jellylike residue is cooled off sufficiently 

 and then thoroughly mixed with 20 cbcm. of cold, absolute alcohol; after a 

 few minutes the alcoholic liquid is carefully decantered, leaving a browuish- 

 yellow residue. The latter is treated again twice or three times raore with 

 small quantities of alcoliol, which are decantered anew. The entire alcoholic 

 liquid is shaken well for about one minute with 3 — 4 gr. of powdered animal 

 cliarcoal and filtered ; the filter is Avashed out once or twice with absolute al- 

 cohol. Wenow evaporate the alcoholic liquid at a température of 40 — 45°C., 

 until the formation of urea crystals becomes plainly noticeable. Thus we have 

 finally before us a mixture of ureine and urea, which is free from minerai 

 matters (chlorides, sulphates, phosphates) and from uric acid and Creatinine^); 

 it is also free from the yellowish-brown coloring matter of the urine, which is 

 insoluble in alcohol and is retaiued by powdered animal charcoal after thorough 

 shaking. Ofteu this mixture of ureine and urea becomes almost solid on 

 getting cooled off and seems therefore to be principally urea with an ad- 

 mixture of some oily, yellowish substance. In reality, however, only % or 

 '^/^ of this residue is urea, whereas % or % of it is ureine; it would be al- 

 most impossible for us to realize this without being aware of it beforchand. 

 Our uext object is to ascertain the proportions of ureine and urea in this 

 residue. It is practically impossible to isolate the ureine without losing a 

 part of it, but fortunately its capacity to décompose Potassium Permanga- 

 nate affords us the means of carrying out our purpose. The following example 

 will serve to illustrate our method : 



Let US suppose, that the weight of ureine -+- urea is 2,4 gr. Judging 

 from expérience we may assume that 'Д of this, 0,6 gr., belongs to urea 

 and %, i. e. 1,8 gr. to ureine. 



Now we know that 1,5 gr. ureine décompose 1,0 gr. KgMngOg in 24 

 hours at ordinary température (18 — 20° С); therefore 1,8 gr. ureine 

 would décompose 1,2 gr. Permanganate. Accordingly we dissolve 1,2 gr. of 

 powdered Potassium Permanganate in 500 cbcm. water and to this solution 

 we add the 2,4 gr. of ureine -+- urea. At the end of 24 hours ^), or still 

 better after 23 hours have elapsed, the permanganate solution is filtered; 



1) One can leave the urine all night on a water bath over a small flame instead of bc- 

 ginning the evaporation on the folowing morning. 



2) Creatinine is practically insoluble in cold alcohol. The absence of thcse substances 

 named can be proved chemically. 



8) It is advisable to shake the solution two or three times during these 24 hours. 



Физ.-Ыат. стр. 134. 4 



