NITROGEN FROM NITRATES AND AMMONIA. 201 
v 
I have, therefore, made several experiments to decide under 
what conditions the formation of asparagine is brought about, 
and whether also its formation takes place in the dark, that 
is, without the reducing action exerted by light in leaves. For 
these experiments, I selected such plants as are rich in starch 
and which form, therefore, under ordinary conditions, but very 
little asparagine by the decomposition of proteids. 
Barley seeds were distributed in three pots, filled with 
moist sand, and kept in the dark. After sixteen days the height 
of the young plants was, on an average 20 cm., but their tips 
began to dry up gradually. At this time, I subjected the plants of 
one pot to analysis, while the second pot was treated with a 1 % 
solution of ammonium chloride, and the third with an equivalent 
quantity of sodium nitrate. Of each of these solutions, 0.5 litre 
was administered at three different times. After one week, the 
growth was found rather insignificant, and the drying at the tips 
had extended. 
After the sand had been carefully separated by washing, the 
whole plants were analysed. Not a trace of ammonia could be 
discovered in them, in spite of their treatment with ammonium 
chloride. The total nitrogen was determined by KjcldahVs 
method, the protein nitrogen by that of Stutzer, and the asparagine 
by that of Sachsse. 
The result was as follows :— 
Date 
15th May 
22nd May 
Plants in 
water, 
amm. chlor. 
sod. nitr. 
Total nitrogen 
3-512 
4-436 • 
d -925 
Protein nitrogen 
2.704 
2:126 
2.066 
Nitrogen in asparagine (I) 0.656 
2.027 
0.977 
A very great 
difference is here 
seen in the 
quantity of 
asparagine, its production being favoured by ammonium salts. 
In a second experiment, young maize of nearly 40 cm. in 
height was placed with its roots in solutions of sodium nitrate 
and of ammonium nitrate, both containing 0.1 % of nitrogen, 
while the control plants were placed in distilled water. After 
(1) No especial attention was paid here to the other amido-compounds, which 
evidently must have been present in all three cases. 
