490 ^ On the 3Iodus Operandi of Phospliorus, 8fC. 



vein of quartz filled the fissure occasioned by it. It is by apply- 

 ing reasoning of this kind to veniferous rocks, that we come at 

 length to apprehend clearly that there are many systems of 

 veins, and that some are posterior to others. 



This branch of geology may become of the greatest importance 

 in mining operations, and practical miners have always, more or 

 less, been guided by the indications belonging to it. All the 

 valuable metals with which we are acquainted, are connected 

 with rocks having veniferous systems : gold and silver may be 

 said to be uniformly contained within veins, or enlarged masses 

 which derive their origin from below. It will probably become 

 the general opinion ere long, that metalliferous masses have the 

 same origin ; and although bog ore of iron, and many other de- 

 posits of iron ore, may be considered as oxides more or less in- 

 durated, and brought into their present places by aqueous de- 

 posit, yet they are oxides from masses which had a subterranean 

 origin. There are many ancient ferruginous sand formations, 

 which were once, no doubt, in the state of recent bog ore, just 

 as many conglomerates were once in the state of gravel. 



We intend to resume this subject when we give an account 

 of the gold region in the southern states. The phenomena we 

 have been treating of will be applicable to the appearances 

 which miners there are now becoming familiar with. 



ON THE MODUS OPERANDI OF PHOSPHORUS ON THE 



LIVING SYSTEM 



By J. R. CoxE, M, D. Professor of Materia Medica and Pharmacy, in the Uni- 

 versity of Pennsylvania. 



Dear Sir, — The perusal of an interesting paper in your Journal 

 for March, by Dr. Harlan, of " Experiments with Phosphorus on 

 a Cat," has induced me to offer you some observations respecting 

 the modus operandi of phosphorus, on the living system ; and 

 which, should you deem them deserving of notice, are altogether 

 at your disposal. They are, to a certain extent, the outlines of 

 my lectures on this subject, which I have, for the last three or 

 four years, delivered to my class. I think the total insufficiency 

 of the explanations hitherto given of the action of this extraor- 

 dinary substance, both as a remedial and as a noxious agent, 

 has heen a principal cause of its depreciation, by rendering 



