SOURCES OF ERROR (iX THE PROCESS) 2OI 



quite possible, for instance, that in any given case a 

 quantity of highly molecular peptones is present in 

 the dialysate. The biuret reaction is surprisingly 

 strong, while the ninhydrin reaction, on the con- 

 trary, is very weak. Conversely, we can imagine the 

 extreme case, in which the decomposition lies below 

 the peptone limit. We obtain a deep blue ninhydrin 

 reaction, which means that many compounds, having 

 the structure of amino-acids, are present ; whilst the 

 biuret reaction gives a negative result. These facts 

 show clearly, that the ninhydrin reaction enables us 

 to recognize many more compounds of the group 

 of albumen decomposites than the biuret reaction. 

 Certainly many points in the whole method of the 

 dialysation process might be modified. In the first 

 place, the apparatus used could be improved. One 

 might consider, for instance, the possibility of con- 

 structing an apparatus, which would enable us to boil 

 the solutions of the ninhydrin reaction simultaneously 

 and equally, and at the same time to prevent anv 

 evaporation. We have purposely made no propo- 

 sitions in this direction, because it seemed to us, that 

 the great advantage of the present method is just 

 that it is simple, clear and concise. We have also 

 made experiments for simplifying the preparation of 

 the organs, and more particularly for shortening that 

 process. Studies on organs, that had been dried 

 and pulverized at 37 C. with special precautions, 



