1819.] History of Anthrazothionie Acid. 45 
of prussic acid (or cyanogen) and sulphur, the former of these 
constituents would have appeared in abundance at the negative 
pole ; and the liquid from that pole when mixed with a solution 
of iron and an acid would have formed a great deal of prussian 
blue. 
Sect. 10.—One part of dry anthrazothionate of potash being 
mixed with five parts of chlorate of potash was inflamed by fric- 
tion and percussion. Concentrated sulphuric acid inflamed the 
mixture still more violently; and when the experiment was 
attempted in a glass tube, a dangerous detonation took place. 
The copper anthrazothionhydrate, considered by Porrett as an 
anthrazothionate of copper, exhibits the same phenomena as 
Porrett has remarked. 1 was in hopes in this way to have’ been 
able to have collected the azote from this last compound, and to 
have determined its quantity in a glass tube over mercury ; but 
the instant the sulphuric acid came in contact with a quarter of 
a grain of hydrate and 1+ gr. of: chlorate of potash, a violent 
detonation took place, the tube was broken to pieces in m 
hand, and I received some slight wounds from the fragments of 
the glass scattered about in all directions. On another occasion, 
the same mixture took fire while I was rubbing it slightly in an 
agate mortar. | 
Sect.11. Metallic Anthrazothionhydrates.—I consider all those 
bulky insoluble precipitates which take place when a solution of 
anthrazothionate of potash is poured into a solution of an easily 
reducible metal, as compounds in which the metal exists in the 
metallic state united with the anthrazothionic acid deprived of its 
hydrogen, that is to say, with anthrazxothion, and with the water 
formed by the union of the hydrogen of the acid with the oxygen 
of the oxide, constituting a metallic anthraxothionhydrate. “The 
following observations exhibit the grounds of this opinion. 
1. When this precipitate is heated in a glass tube, after havin 
been dried for a day in a temperature between 122° and 144°, it 
always lets go a notable quantity of water, which collects in the 
cool part of the tube in the state of drops. 2. This water cor- 
responds (at least I have found this to be the case in the copper 
anthrazothionhydrate) to the sum of the oxygen in the oxide and 
of the hydrogen in the acid. 3. During the escape of the water, 
which takes place at a temperature considérably under a red 
heat, the colour of the substance distinctly alters and becomes 
dark: at the same time there separates a peculiar gaseous body 
with a particular smell, which I, both from the analogy of cya- 
nogen, and because it is absorbed by ammonia and then strikes a 
blood-red colour with a solution of iron, consider as anthraxothion.* 
* Tregret very much that I have not been able to bring forward more direct 
proofs of the existence of anthrazothion, as no method which I attempted succeeded 
with me in separating it from the metallicanthrazothion compounds and procuring 
it in a separate state. Porrett must, in his experiments also, have employed only a 
very small quantity of this substance. It is mnch easier to procure cYanogen in 
