Scientific Intelligence — Geology, 395 



there are nerves, there must be a sense of pain ; but I see 

 no reason why the nerves may not differ as much as the ani- 

 mals to which they belong ; and the use of the vapour of ether 

 shews that nerves may exist without the sense of pain ; for, 

 if I understand the subject rightly, the patient, if not com- 

 pletely insensible, may be sensible of feeling while insensible 

 to pain. 



It may also be objected that I can bring no proof oi brutes 

 not feeling pain in the same degree as man, but only that 

 they do not shew signs of so much suffering. To this I would 

 answer, that while I admit that man has no right wantonly 

 to destroy or mutilate any animal, yet, in searching into the 

 works of creation, seeing that it is a law of nature that some 

 animals must be destroyed that others may exist, we have 

 no right to assume, that in this destruction any animal feels 

 more pain than it shews signs of. 



G. A. ROWELL. 



Apnl 19, 1847. 



SCIENTIFIC INTELLIGENCE. 



GEOLOGY. 



1. On the Accessory Elements of Pyrogenous Rocks, hy M. J. 

 Durocher. — Independently of the silicated minerals which constitute 

 the crystalline rocks called pyrogenous, these rocks contain acces- 

 sory elements, found in small quantities it is true, but which must 

 be taken into account in the study of geological phenomena. M. 

 Durocher's researches on this subject have led him to the following 

 results :-— 



Almost all the pyrogenous rocks contain water in combination 

 which is not disengaged but between 100° and a dull red heat, le 

 rouge sombre. They contain it in proportions very difl'erent, and 

 variable between certain limits ; the ordinary granites, such as have 

 undergone no apparent alteration, contain from 1 to 5 thousandth 

 parts. When a granite has begun to alter by losing its lustre and 

 hardness, the quantity of water found in it increases rapidly to 0*03 

 and 0-04 ; besides, even in granites which appear unchanged, the 

 portion consisting of felspar habitually contains a little water, al- 

 though less than the mica. Petrosilex and the quartz iferous por- 

 phyries contain water like the granites, and so much the more the 



