46 KozLOwsKi : Primary Synthesis of Proteids 



r 



The above quoted equation is in accord with the views ad- 

 vanced by Holzner,* upon the participation of the oxaHc acid, 

 w4io considers it as a product of proteids, destined to decompose 

 the nitrates, phosphates and sulphates of calcium introduced 

 into the plant and to ehminate that element in an insoluble com- 

 pound, a view which was confirmed experimentally as to the lat- 

 ter part by Emmerling. The quantitative relation of both oxalic 

 and nitric acids is just the same in the above mentioned equation 

 as needed by the supposition. It is two molecules of HNO3 for 

 one molecule of oxalic acid. 



On the contrary Palladinf claims, that the oxalic acid is pro- 

 duced in the second stage of the reaction by the transition from 

 amides into proteids and represents the process thus : 



Asparagin. Glucose. Protein (without S). 



23 up + 2H, 



This supposition does not contradict that accepted by Schimper's 

 formulae; Berthelot and Andre found that the amount of oxalic 

 acid in the form of soluble oxalates in fresh leaves Is nearly equal 

 to that found with calcium thus agreeing wdth the last equation in 

 which, as well as in that of Schimper one molecule of oxalic acid 

 is produced for two atoms of nitrogen, the amount of oxalic acid 

 combined with calcium (supposing that the nitric acid is absorbed 

 by the plant only as calcium nitrate) being thus equal to its sur- 

 plus over that element. 



Such are the chief facts and the attempts to give an account of 

 them. Trying to go somewhat further in this line the best w^ay 

 seems to me to start (as did Pfeffer) with a per cent, composition 

 of both asparagin and a proteid, for instance legumin, calculated 

 as to the equal amount of nitrogen, and to compare their dif- 

 ference with the percentage composition of a carbohydrate, as, 

 eg-., glucose. We have then the following table of which the 

 first three columns are taken from Pfeffer's memoir;}: the fourth 

 is obtained by multiplying the percentage composition of the 



* Flora, 1867. 



I Berichte deutsche hot. Ges. 5 : 326. 



J Pringsheim's Jahrbiicher, 8 : 355 se(/. 1872. 



