60 Society for Experimental Biology and Medicine. 



to be proceeding at a particular moment, the catalyser accelerates 

 the progress to the station of equilibrium. 



On the basis of these considerations van't HofT ten years 

 ago predicted that the common reactions of fermentation were re- 

 versible if the appropriate conditions could be secured. This 

 would mean the synthesis of organic substances through the ac- 

 celeration of the reversed reactions, and he expressed the sugges- 

 tion that the syntheses in nature might be regarded as such. 



Of the three large groups of organic substances conspicuous in 

 the living plant or animal body, i. e., carbohydrates, fats and pro- 

 teins, successful reversions have been accomplished in but the first 

 two. Of carbohydrates the following have been synthesized by 

 ferment action : starch, glycogen, cane sugar, maltose, lactose and 

 glucosides. Fats of both the mon-atomic alcohols and of glycerol 

 have been synthesized by ferment action. Two years ago I pub- 

 lished the details of a long series of failures at the synthesis of 

 protein. Since that time I have attempted repeatedly to effect the 

 synthesis of the peptids of Fischer through the action of trypsin. 

 The results were entirely negative. Recently Abderhalden has 

 published the negative results of a similiar set of experiments. 

 Not long ago I succeeded in an effort to effect the synthesis of a 

 protein through the action of trypsin. The detailed description of 

 the work, of which this is but a preliminary announcement, will 

 be published in the Journal of Biological Chemistry. 



Four hundred grams of the protamin sulphate of the striped 

 bass were digested with trypsin until the hydrolysis of the sub- 

 strate was completed. At the close of the digestion, the so- 

 lution was miscible with five volumes of acidulated alcohol with- 

 out the production of any opacity, and gave with cold saturation 

 with sodium chloride no precipitation. This solution was then 

 heated to the boiling point, freed of its sulphuric acid by the addition 

 of barium hydroxid, the excess of barium removed by saturation with 

 carbon dioxide, the mixture filtered hot and filtration repeated until 

 the fluid was clear. This solution then represented a solution of the 

 amino acids, free and combined with carbon dioxide, the products of 

 the hydrolysis of the protamin. The solution was clear, and had 

 an alkaline reaction. This solution was then concentrated until the 

 beginning of precipitation in the cold, from which it was inferred 



