On the Quantities of Nitrates Stored up in Plants 

 under Different Conditions. 



BY 



T. Ishizuka, Nogakushi. 



The amount of nitrates stored up in plants varies not only in 

 different parts of the same plants, but it is subjected to great varia- 

 tion in the entire plants, which depends on the one hand upon the 

 relative amount of nitrates present in a soil and on the other upon 

 the state of development of plants, as, e.g., by rapid development 

 of plants all the nitrates, otherwise deposited in stem and root, 

 would be utilized for the formation of proteid. 



I suspected, however, that, by gradual reduction, the amount 

 of nitrates would also decrease on keeping objects, especially 

 roots, for several mouths in a cool place. 



A series of qualitative tests with diphenylamine and sulphuric 

 acid was first made to acsertain which objects are rich in nitrates; 

 this reaction failed, however, with the roots of Batatas edulis, 

 Nelumbo nucifera, Lilium tigrinum, Solatium tuberosum, Helian- 

 tJius tuberosus, Capsicum longum, Eulrema Wasabi, Colocasia 

 autiquorum, and with the fruit of Cucurbita Pepo. The quanti- 

 tative determinations of nitrates were always made with fresh 

 objects, which were cut into small pieces and extracted with 

 water on a water-bath for half an hour ; the residue obtained 

 by the evaporation of the filtrate was then extracted with alcohol 

 of 60 °/o ; this extract after evaporation to dryness served for 

 the determination of nitrates by the method of Tieman and 

 Schulze.™ 



The results are shown in the following table A. 



(1) In some of the objects the qualitative test already revealed a decrease of nitrates 

 and in some cases an entire disappearance after several months, as in a variety of Allium 

 fistulosnm. On the other hand no decrease was observed with the root of Lappa major, 

 kept from 9th October to 4th Nov., but here the examination showed at once thai the 

 cells of the roots had died oft. 



