J. M. Ordway on Nitrates of Iron. 319 
6.—At 23°C., 100 parts of nitric acid of sp. gr..1°04, with 4 parts of 
the same cast iron, evolved nitric oxyd and yielded a pernitrate. 
a.—100 parts of nitric acid of sp. gr. 1:05, with 50 parts of cast 
iron, emitted hydrogen only. 
arts of nitric acid of sp. gr. 1:05, with ten parts of the same 
iron, extricated hydrogen at first and then evolved nitric oxyd and pro- 
duced a pernitrate. : 
Minute proportions of sulphur or phosphorus are known to 
have a wonderful effect on the physical properties of iron, and 
protoxyd of iron or peroxyd may be precipitated. Oftentimes, 
when air is freely admitted there is not only no loss but an 
actual gain in weight. In such cases probably nitric oxyd in- 
fact forms slowly, but rising no farther than the surface lies g 
a eae ere 
is always a production of nitrate of ammonia, but I have inva- 
riably found the quantity much too small to account for all the 
oxydation that takes place. 
For trials of the purer irons, coarse wire was taken, of such size that 
one meter weighed 15-6 g. A fine wire was used weighing 0°54 g. per 
meter, and therefore for the same weight presenting 54 times as much 
surface as the course. : 
 9,a—At 0° C., 100 g. of nitric acid, of sp. gr. 1°05, with 5-2 & of 
: wire, gave off very little gas and made a protonitrate containing 
0:26 p.c. of ammonia. : 
b—-At 22°C., 105 g. of nitric acid of sp. gr. 105, with 5-2 g. of 
Coarse wire, gave off nitric oxyd, and made a solution of basic pernitrate 
which contained 0:12 p.c. of ammonia, ; 
10,.—At 0°G., 54g. of perfectly pure nitric acid of sp. gr. 1°05 with 
6 g. of fine wire, lost 0-080g. and made a protonttrate and some green 
oxyd. The product contained 0-2 p. c. of ammonia. 2 
° C., 68g. of nitric acid of sp. gr. 1-06 and 35 g. of fine 
Wire lost only 0-090 g. Somewhat more than half of the iron dissolved 
was in the state of protonitrate. There were in the product 0°09 p.c. of 
ammonia. 
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