388 Miscellanies. 



Berzelius to be identical in composition, or at least that no such differ- 



ence existed as to warrant their being considered as different specit - 



The explanation then given by Berzelius has been confirmed by later 

 experiments, and he has published the following additional remarks: 

 "When a portion of common pyrites was permitted to fall ossunder, 

 I found it to be caused by the formation of a small quantity of pro- 

 to-sulphate of iron, which burst asunder the crystallized mass. \\ hen 

 the salt was dissolved in water no trace of free sulphur was obtained, 

 from which it appeared, that the efflorescing pyrites contains parti- 

 cles of FeS (sulphuret of iron,) which, changing to the state of salt, 

 tears asunder the rest which undergoes no change. When the small 

 quantity thus changed into sulphate of iron is compared with that 

 which remains unaltered, I did not think that the results of analysis 

 could be obtained to such a degree of accuracy as to determine the 

 matter with certainty. I have since obtained a satisfactory proof oi 

 the accuracy of this explanation. I heated carbonate of iron gently 

 in a stream of sulphuretted hydrogen. There were formed first sul- 

 phuret, and afterwards bi-sulphuret of iron. The experiment being 

 stopped before all the iron was changed into bi-sulphuret a pyrite was 

 obtained, which in a few days fell asunder in all directions, and 

 changed into a woolly mass of vitriol of ten times its former volume. 

 Sesqui-sulphuret of iron prepared from the oxide has not this proper- 

 ty. It seems, therefore, highly probable, that the falling asunder oi 

 the common pyrites, arises from the electro-chemical action of the 

 electro-negative bi-sulphuret which is here and there mixed with it m 

 small particles. — Berzel. Arsberdt. 1829, p. 129. 



Kohler finds the specific gravity of common pyrites to vary from 

 4.826 to 4.837; of the octohaedral from 4.8446 to 4.9074; and that 

 of the cubical to be 4.9188.— Poggend. An. XIV. 91. 



rf the Mammoth, 



oned 



in the river Oca, near Mourum. "We 



inous name is 



not Mammoth but Mammont, and that a notice of this 



fossil was published as early as 1696 at Oxford, by Ludolf in Ins 

 Grammattica Russica. Prof. Fischer has distinguished six species 

 confounded under the name of Mammont: and he has given tie 

 characters of them in the new memoirs of the Society of Natura - 



255 



kiL — Bib. Univ. Aout, 1830. 



pygmaeus 



