30 O. Loew on the formation of Nitrite of Ammonia. 
ployed. At first I did not remark any reddening, but it be- 
came visible in an extremely short time, when the apparatus 
was placed in the sunlight. I repeated this experiment more 
than once and always found, that—1l, this red color appears 
only at that part of the paper where the evaporation of the 
water takes place. 2. This discoloration does not increase after 
all the water is evaporated and absorbed by the sulphuric 
acid. 3. This phenomenon makes its appearance very quickly 
in the sunlight, and slowly in diffused daylight. 
Now what are the reasons of this phenomenon ? Only one 
explanation suggests itself, and that 1s given by the discovery — 
of Schoenbein, in regard to the formation of nitrite of amm 
nia from water and nitrogen, There can be no doubt that this 
coloration only comes from the nitrite of ammonia, formed by 
the evaporation of such a small quantity of water. The open 
end of the test-tube was in contact with the dried air in the 
face on the ends of the paper. In the ordinary evaporation 
of water, the newly formed nitrite of ammonia is quickly de- 
stroyed again, generating water and nitrogen :— NO’ 0= 
2H,0+2N (O=16.) But in our case every trace of this salt 
is quickly fixed by the alloxan, murexyd ‘being formed, which 
is the cause of this reddening. If one employs a concentrated 
solution of alloxan, the experiment will not always succeed, be- 
cause the crystalline surface formed by it will not allow the 
water to be sucked up, and therefore the place of oe 
orme 
: 
changes. On the other hand, the ammonia salt thus 
amount of carbonic acid and ammonia in the atmosphere, We 
find the proportion of C : N=300:1 (N in the form of am- 
monia), but if we — with that, the proportion of these 
two elements in the body of vegetables, we find on an average 
