1818.] Sir Torbern Bergman. 329 



myself to his chemical papers, on which his reputation in a great 

 measure depends. These, if we omit the Physical Geography, 

 the Notes on Scheffer, the Sciagraphia, and the History of 

 Chemistry, amount to about 48. It will be most satisfactory, 

 perhaps, to take them in tj|g order in which they occur in the 

 Opuscula, as this was the order which Bergman himself gave 

 them. The first two volumes of the Opuscula, and part of the 

 third, were translated into English by Dr. Edmund Cullen and 

 Dr. Beddoes, and the fourth volume by Mr. Heron. I am sorry 

 to observe that Mr. Heron's translation is far from accurate. 

 He often mistakes the meaning of his author, and does not 

 appear to have been sufficiently acquainted with the science of 

 chemistry to understand Bergman's Latin ; which, though suffi- 

 ciently perspicuous to one acquainted with the subject discussed, 

 is not, perhaps, always classical. 



1. He prefaces his Opuscula with a short dissertation on the 

 Investigation of Truth, in which he gives us the rules which he 

 himself always followed in his investigations. These rules are 

 chiefly curious by showing us the state of chemistry when 

 Bergman began his career. It is now universally admitted that 

 the only mode of advancing chemistry is experiment. Experi- 

 ments are now made with so much care that there is very seldom 

 any dispute about facts. The discussions which exist at present 

 in the science relate entirely to the consequences deduced 

 from these facts. The most striking discussion of the kind in 

 modern chemistry is the question whether chlorine be a simple or 

 a compound body ; or rather, whether it contains oxygen or 

 not. Almost all the British chemists, all the French chemists, 

 and most of the German chemists, conceive it to contain no 

 oxygen ; while Berzelius, and one or two individuals in Scotland, 

 consider chlorine to be a compound of oxygen and an unknown 

 basis, according to the original theory of Berthollet and the 

 French chemists. If Bergman's old maxim were to be adopted 

 universally, this dispute would be cut short for the present. 

 This maxim was to consider every body as simple till some 

 evidence be produced that it is a compound, and not to admit 

 the existence of a principle in a body till it can be shown expe- 

 rimentally to exist in it. The experiments of Gay-Lussac, Davy, 

 &c. to decompose chlorine, though varied in every conceivable 

 way, are admitted on all hands to have been unsuccessful. We 

 have, therefore, no evidence at present that it is a compound. 

 Neither lias the existence of oxygen in it been demonstrated by 

 experiments upon which any stress could be laid. The only 

 argument which Berzelius has brought forward is founded on a 

 law of his own invention. Yet he admits that this law does not 

 hold in the case of the nitrates and phosphates. If we suppose it 

 not to hold in the muriates, what becomes of his argument? 

 This supposed law of Berzelius can be shown to be only a parti- 

 cular case of the atomic theory. We can by means of that 



