Chemistry and Physics. 499 
ing and drying apparatus with the hydrogen. When the mixture 
reached the hot platinum, ammonia was produced, the Nessler 
us was turned plue and white fumes were produced wit dro- 
chloric acid. panei experiments showed the production of 
5°9 mgrms. er hour in this apparatus. This result having 
been Shesads to on the ground that the vapor of some salt of 
ammonia might be carried by the saree stream of gas vee! the 
solutions and be dissociated in the Ate ne: a the antho poise as 
0 g r 
nitrogen the ammonia sa : if present might be dissociated and 
yield its ammonia. But on admitting me nitrogen to the cold 
platinum, ammonia was sie ced, 24 mgrms. in an hour. The 
experiment was then repeated with semen obtained by passing 
air over heated copper; but no ammonia appeared. Nor was an 
produced when the nitrogen prepared from the nitrite was previ- 
ously passed over heated copper. Two hypotheses suggested 
themselves: either the heat rendered the nitrogen inactive, or some 
nitrogen oxide, which was present yee Es appareal the ammonia, was 
removed by the hot copper. On examination it appeared that 
the nitrogen prepar ed trom ammonium nitrite — — 
nitric oxide. o remove t ine e nitrogen was passed 
through ferrous sulphate; and to test its purity it was then 
passed through a tared tube pone i or -reduced copper 
heated to redness, the tube being weighed e ery hour. hen 
ae gas passed over a sufficient length of the prions sulphate so- 
lution, no increase in weight was observed in the copper tube. 
The nitrogen being now free from oxides, was used — hydro- 
gen as before; and with cold spongy platinum, 3 mgrms, of am- 
monia was produce in an hour. But when the i cite ‘of gases 
nitrogen, like phosphorus, exists in an active and an inactive 
state, the were produced by heat. —dJ. Chem. Soc., xxxix, 7 
130, Mar ch G. F. 
irregular in form, but reassume their original size and shape on 
adding more acid, Concentrated sulphuric acid acts similarly on 
