On Chemical Equivale7its. 95 



not have been called into action long ago. When the patent of 

 Messrs. Gundry and Neave for a gas engine was first announced, 

 I had little doubt but that I was then anticipated, till the publish- 

 ing of their specification convinced me to the contrary. 



If the above hastily written remarks should appear to you, 

 Mr. Editor, at all conducive to the ends of science, in stimulating 

 others who have more time and talent than the writer, their in- 

 sertion in your next Number will add another favour to 

 Your obliged friend, 



George Lowe. 



XV^I. Oil Chemical Equivaleiits. By Andrew Ure, M.D. 

 Professor of the Andersoniun Institution, Glasgow. 



In compliance vAth. our promise in our last Number, we extract this arti- 

 cle without abridgement, from Dr. Ure's new Edition of Nicholson's Che- 

 mistry. The articles written by Dr. Ure are prefixed by an asterisk, 

 and thig article is so marked in the work. We have tlierefore prefixed 

 his name to it. 



* XliQUiVALENTS (fHEMiCAL). A term happily introduced into 

 chemistry by Dr. Wollaston, to express the system of definite ra- 

 tios, in which the corpuscular subjects of this science reciprocally 

 combine, referred to a common standard, reckoned unity. If, 

 with this profound philosopher, we assume oxygen as the stand- 

 ard, from its almost univeral relations to chemical matter, then 

 calling it unity, we shall have, in the following examples, these 

 ratios reduced to their lowest terms, in which the equivalents 

 will be PRIME ratios : 



The lowest ratio, or equivalent prime of oxvgen being 



1-000 



That of hvdrf>gcn will be . . . . ()• 1 25 



Of fluor ? O-S/f) 



Of carbon, OJ.'iO 



Of pho'^phorus, .. .. ,, I'.^OO 



Of azote, 1 -750 ■ 



Of sulphur, 2-U()(> 



Of calcium, 2-.i.'')() 



Of sodium, 2-!).)() 



Of potassium, 4*I)r)0 



Of copper, S-()() 



Of barium, S'75 



Of lead, l.'VOO, &:c. 



The substances in the above tal)le, susceptible of reciprocal sa- 

 turation, can combine with oxygen or with each other, not only 



i:i 



