PRESIDENT S ADDRESS. O 



where it is deposited upon the ^joints of the soil-particles. 

 The uniform "water-proofing" of the soil-particles is de- 

 stroyed, and they are more easily attacked by the soil 

 bacteria: decomposition being hastened, the fertility is in- 

 creased. 



It is interesting to note that in the January number of the 

 Journal of the American Chemical Society, Schreiner and 

 Shorey contribute two papers upon the glycerides of fatty 

 acids and the paraffin hydrocarbons in soils. These ar? the 

 saponifiable and vmsaponiliable portions of the agricere of 

 Greig-Smith. 



In the department of Bio-chemistry Dr. J. M. Petrie has 

 continued, during the past year, his studies on the nitro- 

 genous compounds present in plants. The proteins separated 

 by different methods from the seeds of Acacia ^;?/c«a/i<Z!a 

 Lave been examined, and evidence has been obtained, by 

 fractional precipitations, of the probable presence of three 

 distinct proteins. Further investigation of the non-protein 

 nitrogenous substances previously shown to constitute so 

 considerable a part of these compovmds which contain 

 nitrogen has been carried out. These substances have not 

 vet been isolated, and the main source of the non-protein 

 niti'ogen is still unknown. Cholin and xanthin bases account 

 for some of this nitrogen, and it has now been shown that 

 the greater proportion of these substances belongs to groups 

 which decompose slowly on hydrolysis with liberation of 

 ammonia. A number of experiments on the changes in the 

 amounts of nitrogenous compounds during the ripening of 

 seeds have ben conducted. The results obtained conlirni the 

 opinion that, as nitrogenous compounds accumulate in the 

 seeds, there is a simultaneous increase in the amounts of 

 both protein and non-protein nitrogenous compounds. No 

 evidence has been obtained that the non-protein nitrogenous 

 compounds in the seeds are transformed into proteins. 

 Further experiments showed that the pods of leguminous 

 plants may act as reserve-holders for the nitrogenous supply 

 to the seeds, even when the pods are isolated from the plants. 



