IV. — CHEMISTKY. 



Art. LIII. — On the Nature of Stinhstone (Anthr aconite). 



By W. Skey. 



[Read before the Wellington Philosophical Society, 15th February, 



1893.] 



It has generally, if not always, to this time been supposed 

 that the odour that the rock known as stinkstone evolves 

 when struck or pounded is, as it is termed, bituminous, and 

 that the substance giving rise to this odour, or that of which 

 it is formed, is some kind of bitumen, or a product of it. 



Happening, however, to have a specimen of this stone the 

 other day to analyse, I observed that the odour had a great 

 resemblance to that of sulphuretted hydrogen, and upon test- 

 ing for this gas in the emanations of the pounded stone I 

 found unmistakable evidence of its presence therein. 



The stone itself was of a light-grey colour, and was en- 

 tirely devoid of all bituminous matter. The proportion of 

 organic matter present was only 0-21 per cent, on the stone, 

 and it was of the same character as the organic matter that is 

 usually associated with limestones. Other specimens of stink- 

 stone I analysed for this gas. 



From these results I make the general statement that 

 most, if not all, of our so-termed stinkstones contain sul- 

 phuretted hydrogen, and that it is this substance, as evolved 

 from it when struck, that gives the odour we observe, and 

 which has been erroneously described as bituminous. 



It only remains for me now to inform you of certain inter- 

 esting results which have been obtained from the experiments 

 that I have made to discover the form in which this com- 

 pound (HS) exists in the stone. 



1. The stone freely evolves sulphuretted hydrogen when 

 simply placed in hydrochloric acid. 



2. The stone, ground very fine, and steeped in water for 

 forty-eight hours, still evolved the gas very freely when after- 

 wards placed in hydrochloric acid. 



