< 372 ) 



H^SOi 48 hours in the waterbath, to change all creatin into creatinin. 

 After that the quantity of creatinin was determined colorimetrically. 

 Every time a determination of the same kind of meat of different 

 animals was made twice. So the following was found: 



Beef I 3.688 gr. creatinin : 4.378 gr. creatin p. Kg. meat 



,, 4.022 ,, ,, ,, ,, ,, 



4. n^Q 



j3 i.yjtju ,, ,) f, J, ,j 



J) 'i.J.OO ,, ,, ,, J, ,, 



5) 'r.Oj.O ,, ,, ,, ,, ,, 



4. 79 I 



J) ^' • "J- >> J> >> )> >J 



5 J O. / OO ,, J, 55 35 3> 



5 5 O.y^fcO ,j ,, 5, ,, ,, 



Even with an abundant use of meat or beef-tea the creatinin excreted 

 by the kidjieys (1,5 a 2 gr. or still more in 24 hours) can but for a 

 part be derived from the food. It is moreover well-known and by 

 the above mentioned researches proved anew that the secretion of 

 creatinin sinks not or scarcely under the norm, when the food does 

 not at all contain creatin or creatinin. The organism itself forms 

 creatin as a product of metabolism from the proteids. It would be 

 possible that the nature of the proteid taken up as food was of signi- 

 fication for the forming of creatin. In that case it was possible that 

 especially such proteids would produce creatin, out of which by 

 hydrolysis much arginin, a more complicated derivative of guanidin 

 could be obtained. According to the researches of Kossel and his 

 disciples, from gelatin twice as much arginin can be obtained as 

 from casein; out of gelatin 9.3 "//), out of casein 4.8 "/e ')• ^^^n 

 HooGENHUYZE and Verploegh have therefore examined by a new 

 series of experimejits whether the use of casein or gelatin increases 

 the secretion of creatinin and if such is the case in what measure. 



V. On April the 7^'^ 1905 a beginning was made with the use 

 of the same food as in series IV. 



V. H. 47 gr. proteid, 98 gr. fat, 337 gr. carbohydr.; 29.5 Cal. p. Kg. 

 V. 47 „ „ 64 „ „ 337 „ „ 30 „ „ „ 



On April the 12''^, 13^'^ 14^'^ 50 gram casein was taken prepared 

 after Hammarsten from cow-milk, in the afternoon at 12 o'clock 

 25 gr. and in the evening at 6 o'clock once more 25 gr. To leave 

 the total chemical energy of the food unchanged, so much fewer potatoes 

 were taken on these days that the quantity of carbohydrates fell 

 from 337 to 287. After that the food was taken as on April the 



1) Zeitschrift f. Physiol. Clicm. Bd. XXXI, S. 207, 



2) Ibid. Bd. XXXIII, S. 356, 



