RICHARDS AND MOULTON. — CUPRIANILINE SALTS. 95 



progressively, so that the use of a thermostat would be necessary to 

 secure absolute certainty in the yield. 



The possibility that most of these compounds might be mere mix- 

 tures has been already suggested; but it is evident that some at least 

 must be definite compounds. The fact that in the case of Nos. 2 and 4 

 a few crystals of an earlier preparation were capable of starting the 

 crystallization of the same substance in larger quantity, throws valu- 

 able light upon this point. The fact that most of the substances fit so 

 closely into the series having eight atoms of copper as the basis seems 

 to indicate a definite law ; for the chances are decidedly against coin- 

 cidence in this regard. The per cent of bromine is of course the best 

 means of determining the agreement with the theory, and the agree- 

 ment is very satisfactory. Each preparation appeared under the 

 microscope to be perfectly homogeneous, so that if the substances are 

 mixtures, the components must crystallize together. 



From this series of compounds one would infer the possible exist- 

 ence of cuprianiline acetate, but many repeated trials to prepare this 

 compound in a pure state ended in failure. Several different new com- 

 pounds were obtained during this search, one of them probably having 

 the formula Cu2(C6H7N)3(C2H302)4, for it contained 19.82 per cent of 

 copper. Another compound, which consisted, like this last, of long 

 light blue needles, contained only 19.10 per cent of copper ; while two 

 others, a brown and a black powder, contained respectively 21.80 per 

 cent and 17.28 per cent. All of these compounds, together with 

 others containing chloriue and iodine instead of bromine, and other 

 substituted ammonias in place of aniline, will soon be investigated 

 further at this Laboratory. 



