Mr. Lyon's Observations on Magnetic Substances, 415 



That some oxide of nitrogen, which in the present state of 

 our knowledge of that class of compounds seems to be the 

 nitrous acid, is capable of rendering phosphuretted hydrogen 

 spontaneously inflammable, when that oxide is present to the 

 extent of one ten-thousandth y art of the volume of the gas: 



That such ga's has a general resemblance to phosphuretted 

 hydrogen as obtained in the spontaneously inflammable state 

 by ordinary processes, which last probably owes its ready ac- 

 cendibility to the presence of an equally minute trace of a 

 volatile compound of phosphorus and oxygen, analogous to 

 nitrous acid. 



LVIII. Observations on Magnetic Substances. By Mr. David 



Lyon.* 



TRON was for a long space of time the only substance which 

 * was known to be capable of exhibiting magnetic pheno- 

 mena. It was afterwards found that two other metals, nickel 

 and cobalt, are endowed with a similar capacity. 



Hence it appears that magnetism is not a peculiar essence 

 of one particular substance only; and that whatever be its na- 

 ture, it is not confined to one substance alone, but is common 

 to different chemical elements. It may, therefore, be properly 

 inquired, whether in any principal qualities, or in the numeri- 

 cal values of qualities, these elements do resemble one another, 

 and are likewise distinguishable from all the other elements. 

 For if such be the case, we may come to know on what mag- 

 netism depends, or in other words, to account for its presence 

 in these elements and in no other; although we do not enter 

 upon the question, as to what magnetism really is, or what is 

 its physical origin. 



The atomic weights of the three magnetic elements, as stated 

 by Berzelius, are as follows : 



Nickel 739-51 



Cobalt 738- 



Iron 678*43 



The specific gravities, as stated in Pouillet's Elemens de 

 Physique, are, 



Nickel 8-27 



Cobalt 7'8 



Iron 7*207 



Thus, both in the atomic weights and in the specific gravities, 

 we observe that the three magnetic substances or elements 

 have values near together : and on inspecting the values of all 

 the chemical elements, we observe further, that there is no 



* Communicated by the Author. 



