196 Ethyla  y 9g 4 °. thyli }] ws Nitrate. 
tals were obtained, which were washed with alcohol, and dried 
over oil of vitriol. The carbon and hydrogen were determined 
by burning with lead chromate, the nitrogen by Schiff’s method 
with copper oxide and displacement of air by a slow stream of 
carbonic acid, and the silver by simple ignition. The following 
results were obtained from the two crops above mentioned : 
Atomic Calculated for 
g. 
1st crop. 2d crop. Mean. ratio. CyHioN;0s 
Carbon 18°32 18°33 18°33 18°75 
Hydrogen 4°31 4-16 4°23 10°8 3°91 
Nitrogen 16°63 16°65 16°64 3 16°41 
ilver 2°06 41°99 42°03 1 42°18 
Oxygen 18°77 3 18°75 
100°00 100°00 
These results give a formula different from NO,Ag 2(C,H, 
ONH,), which is given in Watts’ Dictionary, vol. i, p. 108, as 
vowed representing the substance. Taken together with 
iebig’s analysis, they also indicate that the same body is 
formed in both aqueous and ammoniacal solutions. 
,oN,0,Ag differs from two equivalents of aldehyde- 
ammonia and one equivalent of silver nitrate by two molecules 
of water, thus: 2(C,H,ONH,)+AgNO,—2H,0=C,H,, 
O,Ag. This view of the chemical process is supported by the 
reactions of aldehyde with benzamide and aniline, in which 
water separates, and also by the following experiment: 29°2 
grams of a mixture of silver nitrate and good crystals of alde- 
hyde-ammonia, in the proportion of one equivalent or 17° grams 
of the former, to two equivalents, or 12-2 grams of the latter, 
were dissolved in 40 ¢. e. of concentrated ammonia-water. The 
solution was evaporated in a weighed dish, first by a blast from 
a laboratory bellows and finally over oil of vitriol until the 
weight was constant. The residue weighed 25:445 grams. The 
weight, according to the above formula, should have been 25°600 
grams. The difference of 0-155 grams between the experimental 
result and theory may be ascribed to the slight decomposition 
the substance had undergone in drying, which was shown by 
the small black residue it left when treated with ammonia- 
water. 
When an ammoniacal solution of aldehyde-ammonia and 
silver is evaporated at 20° to 30°, hydrous monoclinic transpar- 
ent crystals separate, which do not change rapidly on damp 
days, but become opaque with loss of water in dry weather. 
Together with the hydrous crystals, small poorly defined tricli- 
nic crystals form which do not become opaque in dry air. 
latter are transparent and colorless, or more frequently have @ 
resinous tinge. Dr. E.S. Dana has studied the crystalline form 
of both the hydrous and anhydrous crystals, and gives his re- 
