HISTOBY OF THE ATOMIC THEORY. 19 1 



If a+B— Z>=C and HA— a=D then a=C-f6— B=6-|-A 

 — D and C— B=A— D, so also D— B=A— C. In addition 

 6=a-fB—C=D— A-fa. 



Theorem 1. P. 125. 

 " The chemically attracting power by which one element 

 a enters into neutrality with another A — a presupposes an 

 opposite action of the same kind in the latter, and these 

 two powers are equal to each other. 



Theorem 2. P. 128. 

 " If a neutral compound A whose elementary masses A — a 

 and a are removed from combination by a definite quantity of 

 a third element J, and the whole mass of one element a for 

 example is set free, the force that causes this phenomenon is 

 equal to the difference between the separating element h and 

 the separated element a. 



Theorem 3. P. 130. 



" When two neutral compounds A and B, the masses of 

 whose ingredients are A — a, a and B — 6, b mutually decom- 

 pose each other, so that the new products A — a-\-b and 

 B — 6+ a are formed, the forces that partly cause and partly 

 hinder this action, are equal to the difference of affinities of 

 the elements A — a and B — h towards each of the elements 

 a and 6." Afterwards he said, 



" When I finished the pure stoechiometry, two years ago, I 

 did not think it would be needful to make any additions to its 

 contents. In the first place I thought it had all that practical 

 stoechiometry required, &c.* 



Vol. II., Par. V., P. 4. 

 Having decided by experiment that 1000 parts carbonate 

 of lime contain 559 earthy matter, be sums up as follows 



• Preface to Vol. I., Part 2. 1794. Later than Vols. IL and IIL 



