12 On the Daltonian Theory of [July, 



merits; but in the ingenuity of his contrivances, and the happy 

 analogies by which hi? experiments are directed. 



The arguments of Professor Berzelius are entirely analogical ; 

 and, as far as I can perceive, not in the least hostile to the opinion 

 of Mr Humphry Davy : for the theory of definite proportions, as I 

 shall show in this paper, applies as accurately to the one hypothesis 

 as the other. Mr. Henderson's arguments are of the same kind 

 with those of Professor Berzelius ; and he has been misled in 

 almost all hi< examples, by adopting inaccurate data (though the 

 best that could be found) respecting the composition of the different 

 substances. 



The French chemists (I allude to Gay-Lussac and Thenard) 

 seem to me to have been aware of the lameness of their arguments, 

 and to have adopted the old opinion merely as a compliment to 

 Berthollet, whose reputation was chiefly raised by his original expe- 

 riments on chlorine, and his supposed analysis of it. 



I am surprised that the assertion of Gay-Lussac and Thenard, 

 that muriatic acid gas contains more than a fifth of its weight of 

 water, did not startle the chemical world in general. No analogy 

 can be adduced in favour of such an opinion, but abundance 

 against it. The experiment of Dr. Bostock and Dr. Trail, re- 

 peated by Mr. Murray, by Sir H. Davy, and by Dr. Hope, is quite 

 inconsistent with such an opinion. I am surprised that any stress 

 should be laid upon the appearance of a minute portion of water 

 when salammoniac is for, tied by the union of muriatic acid and 

 ammoniacal gases. Whoever will attend to the experiments of Dr. 

 Henry will perceive the extreme difficulty, if not impossibility, of 

 excluding all moisture in such cases. 



1 think then that in the present state of our knowledge we have 

 no other alternative than to adopt the opinion that chlorine is a 

 simple supporter of combustion analogous to oxygen and iodine, 

 and capable, like them, of combining with the different combustible 

 bases, and of forming a class of bodies analogous to the oxides and 

 acids constituted by the union of oxygen to the same bases. I 

 consider Sir H. Davy's mode of naming these compounds as very 

 unfortunate. It is not only contrary to the analogy of our language, 

 and of all the languages of Europe, except perhaps the Italian; but 

 it introduces into chemistry above forty new words, and therefore 

 greatly increases the difficulty of becoming acquainted with the 

 science. 1 think on these accounts there can be no hesitation in 

 rejecting it. 'J here is a very obvious method of naming these 

 compounds, suggested by the term oxide. We have only to apply 

 to them all the appellation chlofide, and distinguish each species by 

 adding the name of the base. Thus chloride of snip hur will be my 

 muriate of sulphur, ;r chloride of phosphorus and per chloride of 

 J hoif it trus will be the photphorane and plwsphoraun of Davy, chlo- 

 ride of sduer will be horn silver, or muriate of silver, and so on. 



The chlorides of the simple combustibles are all very satisfactorily 



