i 5 o SCIENCE PROGRESS. 



knowledge concerning these decompositions has been ad- 

 vanced by numerous chemists and physiologists, references 

 to whosa works will be found in a paper by Dr. Brodie in 

 the September number of this journal. Among the names 

 there mentioned it will be seen that Schiitzenberger's 

 figures very largely, and to this observer belongs the 

 credit of an attempt (one of the earliest conducted on 

 scientific lines) to build up from the compounds he had 

 obtained from albumin, something like the original proteid 

 he had broken up (i). 



In order to effect the synthesis of proteid material, he 

 considered it necessary to combine a molecule of a leucine 

 {i.e., an amido-fatty acid) with a molecule of a leu- 

 ceine (an amido-acid of the acrylic series) with elimination 

 of water, and then to combine this complex group with one 

 or more molecules of urea, and oxamide, also with elimination 

 of water. The method he had adopted for the breaking 

 up of proteids was boiling with alkalis ; this led to hydra- 

 tion, so in any attempt at synthesis he recognised as a sine 

 qua non the necessity of some method of dehydration. 

 The provisional formula he gives is the following : — • 

 H 2 C 2 + + 2NH3 + 3 C m H 2m+I N0 2 + 3C n H 2n _ x N0 2 with 

 elimination of eight molecules of water. This would give 

 C q+2 H 2q _ s N 8 O s , and if q = 28 the percentage composition 

 calculated from the formula agrees closely with that of 

 albumin. 



Accordingly amido-compounds, leucines (C m H 2m + 1 N0 2 ) 

 and leuceines (QH^^NO,), were mixed with about 

 10 per cent, of urea and finely powdered. The mixture 

 was dried at no C, and intimately mixed with 1*5 times 

 its weight of phosphoric anhydride, and heated in an oil 

 bath. At 120° there is no change, but at 125° dehydration 

 takes place very rapidly, and the mixture becomes pasty, 

 but solidifies to a compact product without any darkening. 

 This was dissolved in water, the solution mixed with excess 

 of alcohol, and the pasty precipitate so produced washed 

 with alcohol and redissolved in water. Phosphoric acid was 

 removed by means of baryta, and the filtered liquid when 

 concentrated on a water bath, yielded an amorphous pro- 



