1813.] Dijin'ile Proportions in Chemical Combinations. 3:J 



and bases belong entirely to Mr. Dalton ; without whose labours 

 the theory would probably have still remained unknown. On 

 the Continent the notions originally established by Dalton have 

 been adopted, and ingeniously extended in certain cases by Gay- 

 Lussac ; and Berzelius has published a most elaborate, extensive, 

 and accurate set of experiments on the same subject, which 

 fully confirm the Daltonian doctrine, while he has deduced 

 several subordinate laws from his analyses, which, though in 

 some measure empyrical, are nevertheless of very considerable 

 importance in determining the constitution of bodies. . 



In this country less attention has hitherto been bestowed upon 

 Dalton's theory than could have been anticipated from the 

 sagacity and enlightened views of many of our ciiemists. Dr. 

 Bostock has even written an essay against it ; but from the well- 

 known candour and liberality of this able philosopher, I have no 

 doubt that he will embrace it with ardour as socn as his doubts 

 are removed. Sir Humphry Davy has embraced the Daltonian 

 theory with some modifications and alterations of terms ; but his 

 notions are not quite so perspicuous as those of Mr. Dalton, and 

 they do not appear to me so agreeable to the principles of sound 

 philosophy. These, as far as I recollect, are the only chemists 

 in this country who have written upon the subject (some observa^ 

 tions of Dr. Wollaston, and of myself, excepted); though not 

 the only persons who have embraced the opinions of Mr. Dalton. 

 I shall in this essay state, in the first place, the nature of the 

 theory, and the grounds upon which it has been advanced ; in 

 the second place, I shall state the laws, or subordinate canons, 

 which have been deduced from analysis, in consequence of the 

 introduction of this theory; and in the third place, I shall give 

 a table of the numbers representing the proportions in which 

 substances combine, deduced from the application of the Dalto- 

 nian theory to the most accurate analyses hitherto made. 



I. Outline of the Daltonian T/irory. 



^ It may be necessary to mention in the outset that I propose to 

 give the view which I have been accustomed myself to take of 

 the subject, and that 1 would not be understood to make Mr. 

 Dalton answerable for the opinions which 1 shall state. 1 call it 

 the Daltonian theory because I consider it as belonging to Mr. 

 Dalton ; because he lirst suggested it to me, and set me to think 

 on the subject; and, of course, every thing here stated origi- 

 nated from him, either directly, or at least indirectly. 



I. With respect to the nature of the ultimate elements of 

 bodies, we have no means of obtaining accurate information ; 

 but it is the general opinion that they consist of atoms, or minute 

 tolids, incapable of farther division. That these atoMS are imrj 

 Mathematical points surrounded with spheres of attraction and 

 Vol. II. N° I. C 



