1870.] Chemistry. 529 



relates further that he (M. Thenard) is at present engaged an 

 researches of organic acids which contain even 24 per cent, of 

 silica entirely disguised. When ulmic acid is treated by ammonia, 

 azhumic acid is formed ; this contains nitrogen so fixedly, that it is 

 only eliminated at a temperature of about 1200°: This acid is pos- 

 sessed of the remarkable property of readily dissolving silica, and 

 combining therewith in the same manner as the compound alluded 

 to above by Dr. Friedel. The author also states that although his 

 researches on this subject are not yet quite concluded, he is justified 

 in stating that all arable and garden soil, and far more so farmyard 

 manure, contain similar organic silicious compounds which play an 

 important part in the feeding of the plants. 



That indefatigable savan, the Abbe Moigno, has recorded that 

 when picric acid is introduced into a vessel containing ozone, a 

 violent detonation instantaneously takes place, a new proof of the 

 danger attending experiments with nitrogenous compounds contain- 

 ing nitrogen only loosely bound. 



The utility of mixing peroxide of manganese, for which, how- 

 ever, may be substituted substances such as peroxide of iron, oxides 

 of zinc and tin, burnt gypsum, and others, provided they are pre- 

 viously well dried (best by ignition) with chlorate of potassa, is 

 based according to Dr. G. Krebs upon the fact that the substances 

 alluded to, which are infusible by themselves, are the carriers and 

 transferers of heat to the chlorate of potassa, each particle of which 

 is surrounded with a source of heat, which aids its rapid decom- 

 position. The peroxide of manganese is prevented from being 

 itself decomposed, because the chlorate of potassa withdraws from it 

 heat, for the purpose, first of its own fusion, whereby heat becomes 

 latent; secondly, by its decomposition. The author states that 

 when oxide of iron, or peroxide of manganese, is strongly heated 

 in a crucible, and chlorate of potassa very gently fused at the same 

 time by itself in a porcelain dish, the addition of the moderately 

 hot oxides to the fused chlorate causes the evolution of oxygen to 

 set in instantaneously, and with so great violence, that unless this 

 experiment be performed in open vessels and with small quantities 

 at a time, serious explosions may occur. 



A compound of hydrogen and mercury, which the discoverer 

 calls Hydrogenium-amalgam, has been prepared by 0. Loew, by 

 shaking together in a vessel, to be kept very cool, a mixture of 

 mercury containing from 1 to 2 per cent, of metallic zinc, along 

 with an equal bulk of a solution of chloride of platinum containing 

 10 per cent, of solid chloride. A slimy mass is obtained, devoid of 

 metallic lustre and prone to decomposition, owing to the presence 

 of zinc and some compounds of that metal ; but on treating the 

 mass with dilute hydrochloric acid, a body having the consistence 



