46 M. Grotthuss on the (Jan, 
The greatest part of the sulphur unites itself with the metal furm- 
ing a sulphuret ; azote, or rather carburetted azotic gas, is given 
off, a portion of the carbon remains long behind, and by the 
increase of heat and the free admission of air it glows like a 
pyrophorus, a little before the temperature rises to redness. 
After this pyrophoric appearance, but not before, sulphate of 
copper may be washed out of copper cenieanethannals lanl: 
4. The metallic sulphuret which remains behind after the hydrate 
has been exposed to a red heat without the access of air, con- 
tains the metal in the metallic state. Nitric acid dissolves it 
when assisted by heat with the evolution of abundance of nitrous 
gas, and leaves the sulphur behind. 5. The copper anthrazo- 
thionhydrate is not sensibly attacked by concentrated muriatic 
acid even at a boiling temperature, provided care be taken nof 
to allow any oxidizing substance to come in contact with it ; but 
if a little of any such substance, for example, of chlorate of 
potash, be added, the copper is oxidized, and the anthrazothion 
decomposed. If this muriatic solution be evaporated to dryness, 
and the dry mass mixed with potash ley, a strong smell of ammo- 
nia becomes perceptible. Now if the metal in this compound 
were in the state of an oxide, concentrated muriatic acid would. 
surely be capable of separating the acid from the oxide, as it 
does from all the alkaline anthrazothionates, and even with 
much greater facility ; but this, however, is not the case. The 
muriatic acid is never able to dissolve the metal till an oxidizing 
body comes into play and gives out its oxygen to the metal. 
6. During the combination of anthrazothionic acid with easily 
reducible metals, the former must undoubtedly reduce the latter, 
because three of its elements, namely, hydrogen, sulphur, car- 
bon, are capable of reducing not only these, but many others to 
that state, and the fourth element, azote, is at least neutral, if 
it does not rather promote disoxidation. Ought not then the 
hydrogen, the most disoixdizing of all the elements, be capable of 
reducing these oxides to the metallic state, since the water 
thereby produced may combine with the metallic anthrazothion 
(or anthraxothionide, if that name be preferred) and form a 
hydrate !. 7. To show in the last place that the opinion which I 
entertain respecting these compounds is at least not more hypo- 
thetical than Porrett’s, I may observe that hitherto nobody has 
been capable of deciding certainly about the way m which the 
elements are united in a compound. Nobody can, for example, 
in this case show that the hydrogen of the acid does not unite 
with the oxygen of the oxide (which from the preceding obser- 
vations is liighly probable); but that the former remains in the 
acid, and the latter in the oxide, after these two have united 
together and constituted a new body. In this point of view 
quantities than anthrazothion; because some of the cyanogen compounds are pre« 
pared ona large scale, and may be had in quantities, while no anthrazothion come 
pounds arg to be met with in apothecaries’ shops, 
