496 U. SUZUKI. 



IN 100 PARTS OF TOTAL NITROGEN. 





Control plants 

 dried on 

 13th 



Plants in day 

 light dried 

 on 20th 



Plants in dark 

 dried on 

 20th 





100.0 



100.0 



100.0 



Albuminoid nitrogen 



43-6 



32.o<i) 



24.1(1) 



Nitrates nitrogen 



4.8 



3.2 



3.1 



The nitrates nitrogen of the control plants being taken as 100 

 the following numbers are obtained : 



Control plant Plants in day light Plants in dark 

 Nitrates nitrogen 100. 68. 76. 



This result shows that the formation of proteids from nitrates 

 does not take place in darkness when the amount of sugar present 

 is very small. 



V. EXPERIMENT WITH POTATO PLANTS. 



(a). Young potato plants tolerably rich in nitrates, were 

 carefully removed from the field and washed. One portion of it 

 was directly dried, while the other was put in a sugar solution 

 half saturated with CaSO^, from which it was put into the mineral 

 solution mentioned above once in every three days and left in it for 

 a whole day ; the plants being kept all the while in the dark. The 

 experiment lasted from May 12 to 18. The temperature -varied 

 from 8°C. to I5°C, 



(i) As the plants were kept in a warm house, the growth was considerable in both 

 ■cases, and the decomposition of proteids was consequently also considerable. 



