Combinations of different Metals and Chlorine. 275 
Hence, considering the deficiency of weight, as indicating 
the quantity of combined water, 100 of the native sub-muriat 
of copper seem to consist of 
73.0 brown oxide 1*15.8025 chlorine 
16.2 muriatic acid = << 
10.8 water [_ .47 hydrogene. 
This analysis, allowance being made for difference of theory, 
nearly agrees with that of Klaproth. 
M. Proust, I believe, first discovered an artificial compound 
similar to the native sub-muriat of copper. He obtained it, in 
the preparation of the nitro-muriat of copper, and also by a 
partial abstraction of the acid of the deliquescent muriat, by 
means of an alkali. I have found that it may be procured in 
several other ways. It may be made directly by adding the 
hydrated blue oxide of copper to a solution of muriat of cop- 
per ; and it may be very readily and economically prepared, 
by exposing to the atmosphere slips of copper partially im- 
mersed in muriatic acid ; and it is also produced by the expo- 
sure of cuprane to the atmosphere. Its production in the last 
instance is accompanied with that of the deliquescent muriat ; 
and the formation of both seems to be owing to the absorption 
of water and oxygene ; for cuprane, I have found, though appa- 
rently not in the least acted on by dry oxygene gas, is quickly 
changed when moistened with water and confined in ajar of 
this gas, and there is a rapid absorption of oxygene.* 
I have not examined all the specimens obtained by these 
different methods minutely, though sufficiently, I conceive, to 
* I have been informed that submuriat of copper is sometimes found in the neigh' 
bourhood of volcanoes, particularly in that of Vesuvius. By means of the above facts,, 
it is evident that its production might be accounted for in such situations. 
