238 On the Effect of the Quantity of Matter in 



But Berthollet was not content with the establishment of this 

 law. He drew the additional conclusion that exoept where 

 the existence of definite proportions is determined by the 

 forces of cohesion, elasticity, etc. chemical agents combine 

 in all proportions indiscriminately. As this was altogether 

 at variance with the views which chemists were presently en- 

 gaged (with a zeal hardly commensurate to its vast impor- 

 tance) in establishing, respecting chemical combination, 

 comprising the doctrine of definite proportions and the 

 atomic theory, they looked with an evil eye upon Berthollet, 

 his experiments and conclusions — regarding him apparently 

 as a powerful antagonist, who might suddenly demolish 

 their favorite doctrines. Two of his experiments were 

 attacked by Sir Humphrey Davy, who in the Elements of 

 Chemical Philosophy, supposed himself, and was supposed 

 by others, to have "pointed out several sources of fallacy, 

 which had escaped the observation of Berthollet."* The 

 confidence of men of science in the accuracy of the French 

 chemist, was thus shaken and his experiments and opinions 

 alike neglected. 



And yet Berthollet was by no means that inaccurate and 

 short-sighted being he has sometimes been represented to be 

 — and I think it will appear on a careful examination of his 

 experiments, that the fallacy was on the side of his critics 

 and commentators. 



"I have kept an equal quantity of potash and sulphate of 

 barytes in a small quantity of boiling water. The potash 

 had been prepared by alcohol and contained no carbonic 

 acid : the same served for the following experiments. The 

 operation was performed in a retort, and consequently not 

 in communication with the air; and it was continued until 

 the mixture was desiccated; the residue was washed with al- 

 cohol, which dissolved the potash, and after that with water, 

 which also produced an alkaline solution, the alkali of which 

 1 saturated with acetic acid ; after" which by evaporation, the 

 solution yielded crystals possessing all the characters and 

 qualities of the sulphate of potash. Whence it appears that 

 the sulphate of barytes was partially decomposed by the pot- 

 ash, and that the sulphuric acid was divided between the two 

 bases." — BerthoUefs Researches into the laws of Chemical 

 affinity. 



'" Paris's Med. Chemistry. 



