CHEMICAL SCIENCE. 279 



the action of bicarbonate of lime with simultaneous formation of gypsum, 

 or by bicarbonate of soda producing at the same time chloride of sodium. 

 In this way have been formed those magnesian limestones which are not 

 associated with gypsums. The intervention in this process of the waters of 

 alkaline metalliferous springs, will explain the metalliferous character of 

 many magnesian rocks. The source of the bicarbonate of soda has been 

 the decomposition of feldspathic rocks, which have formed clays and clay 

 slates; and the action of this alkaline carbonate upon the lime and magne- 

 sian salts of the primitive sea, has given rise to limestones and dolomites, 

 as well as of the sea-salt which we find in the ocean. At the sa/ne time, 

 the removal of the carbonic acid of the atmosphere, which was absorbed 

 by the soda and then fixed in the form of carbonate of lime and magnesia, 

 has served to purify the air, and fit it for the support of the higher orders 

 of plants and animals. In this relation between the atmosphere, the ar- 

 gillaceous rocks, the limestones and the salt of the sea, we have a remarkable 

 instance of the balance of chemical forces in inorganic nature. Silliman's 

 Journal, Vol. xxviii. pp. 170 365. 



ON THE NUMERICAL RELATIONS EXISTING BETWEEN THE 



ELEMENTS. 



The American Journal of Science for January 1859, contains the first part 

 of a paper on the above subject, by M. Carey Lea, Esq., of Philadelphia, in 

 which certain numerical relations between the elementary bodies, before 

 unnoticed, or only partially noticed, are developed in a remarkable and 

 exceedingly interesting manner. 



Few of the so-called elements present more directly marked analogies than 

 nitrogen, phosphorus, arsenic, and antimony ; while Cahours and Hofmann 

 have shown that phosphorus stands in every respect intermediate between 

 nitrogen and arsenic, forming compounds of the type 3(C4H 5 )PHC1, etc., 

 like the nitrogen compounds, as well as those of the type 3(C4Ho)P02, 

 etc., like those of the arsenic and antimony groups. These authors further 

 observe, that the equivalents of phosphorus, arsenic, and antimony, differ 

 by nearly the same number (44 to 45), but that nitrogen does not exhibit 

 this relation. Beyond the fact of the approximate equality of these two dif- 

 ferences, the analogy has never been extended. Mr. Lea, however, shows 

 that this relation may be extended not only to nitrogen, but, with exactness, 

 to many other elements. 



Thus, if we form a descending arithmetical series, beginning with anti- 

 mony = 120-3, and diminishing by a common difference of 45 (45'3 in one 

 instance, 44 in several), we shall find that such a series does not cease with 

 the third term, P = 31, but gives for a fourth 14, the exact equivalent of 

 nitrogen with a negative sign. The fifth term will be 59, the exact equiv- 

 alent of tin (with a negative sign). The sixth will be 104, or very nearly 

 the equivalent of lead (also with a negative sign). The seventh 149, very 

 nearly double the equivalent of arsenic, a previons term in the same series. 

 These results exhibit themselves more strikingly when tabulated, as follows : 



It will be seen presently that the number 164, the eleventh term in the 

 following table, occurs also in the ascending positive series, and may repre- 

 sent the equivalent of a metal existing, but as yet unknown. 



If we examine the position occupied by antimony, arsenic, phosphorus, 

 and nitrogen, in the electro-chemical scale of Berzelius, we shall find that in 



