BimrZEN THE ATOMIC WEIGHTS. 251 



strong oxidizing agent, and resembles closely Nitrous Acid, and the atomic weight of 

 Chromium falls into the Six Series just below that of Xitrogen. Manganic Acid, on 

 the other hand, resembles Sulphuric Acid, with which it is isomorphous, and the atomic 

 weight of Manganese would place it in the Eight Series. In like manner Osmium in 

 many of its properties resembles Platinum and the other metals with which it is asso- 

 ciated in nature ; but, unlike them, it forms a very remarkable volatile acid, whose 

 insupportable and suffocating odor as well as composition reminds one of the acids of 

 the Nine Series, and its atomic weight seems to justify the apparent analogy. Gold 

 likewise, though the noblest of metals, yet in some of its chemical relations resembles 

 much more closely the members of the Xine than of the Four Series, and here again 

 its accommodating atomic weight seems to account for its double-sided character. 

 Several other examples of similar aihliations are given in the Table, but do not need 

 explanation. 



In the description just concluded of the classification of the chemical elements, 

 which is offered in this memoir, I have not entered into detaUs, for to have done so 

 would have been to write a treatise on Chemistry. I have confined myself almost 

 exclusively to general points, and only referred to those particulars which I thought 

 might present doubts. I hope that I have been able to show, first, that the chemical 

 elements may be classified in a few series similar to the series of homologues of 

 Organic Chemistry ; second, that in those series the properties of the elements follow 

 a law of progression ; and finally, that the atomic weights vaiy according to a similar 

 law, which may be expressed by a simple algebraic formula. As already intimated, I 

 have endeavored to prove the correctness of the classification on general grounds, in 

 order that it might appear that the simple numerical relation which has been discovered 

 between the atomic weights is not a matter of chance, but is connected with the most 

 fundamental properties of the elements. I might leave the subject at this point, but 

 the existence of the law which I wish to establish will be proved more conclusively if 

 it can be shown, not simply that the general properties of the members of each series 

 vary in a regular manner, but also if in one or more cases the exact law of the varia- 

 tion can be pointed out 



There are but few properties of the elements which are subjects of measurement, 

 and which therefore can be compared numerically. Such are the specific gravity in 

 the three states of aggregation, the boiling and melting points, the capacity of heat, 

 and a few others. It is easy to see that there are but few of these properties the law 

 of whose variation in the series we could reasonably expect to discover in the present 

 state of science. Most of them evidently depend upon molecular forces with which 



VOL. V. XEW SERIES. 35 



