173 Remarks on the Essay of Dr. Berzel'ms [MAncH, 



is nothing apparent in the atomic theory to prevent such combina- 

 tions. 



After having the atomic principles in contemplation for ten years, 

 I find myself still at a loss, occasionally, to discriminate between the 

 combinations which contain 2 atoms of a given body from those 

 which contain only 1 atom. Hence an atom that weighs 50 may 

 be sometimes put down as weighing 100. It is owing to the diffi- 

 culty on this head, I apprehend, that Berzelius considers the atom 

 of lead at twice the weight 1 do ; in consequence, he makes the 

 yellow oxide of lead to consist of 1 metal and 2 oxygen. As for 

 the red oxide of lead, 1 consider it, after Proust, as being probably 

 made up of the yellow and brown oxides in combination. 



One example adduced as incompatible with the atomic theory 

 appears to me peculiarly unfortunate. It is an oxide of iron con- 

 taining 37'8 oxygen upon 100 iron, discovered by Gay-Lussac. 

 J^ow this may be accounted to be a compound of 2 atoms of the 

 red oxide and 1 of the black ; for such a compound must contain 

 37'3 oxygen upon 100 of iron, which agrees more nearly with the 

 experiment ihan we have any right to expect in sucli case. 



The third and last difficulty which Dr. Berzelius has brought 

 forward as militating against the atomic theory is derived from the 

 analysis of what he calls organic atoms; that is, atoms composed of 

 more than two elementary substances. The atom of oxalic acid is 

 adduced as an instance. 



It would be a singularly curious circumstance, and well worth 

 recording in tl'ic annals of chemistry, if the composition of the 

 oxalic acid itself should bid defiance to the atomic theory, or to that 

 of definite proportions, whilst the compounds formed with it were 

 originally produced by Dr. Wollaston and Berard as exhibiting the 

 most striking illustration of the doctrine. I was indeed surprised 

 to see the results of such an analysis of oxalic acid published by 

 Berzelius, to whose accuracy in general I can subscribe ; but still 

 more so to have it afterwards referred to as militating against my 

 doctrine. He concludes its constitution must be 1 atom of hydrogen, 

 27 of carbon, and 18 of oxygen ; tiiat is, 1 atom of hydrogen with 

 ■45 other atoms. Were it a matter of necessity, an atomist might 

 conceive 1 atom of iiydrogen surrounded by 9 of carbon, and the 

 compound globule to have 18 atoms of carbonic oxide adhering to 

 it. But this would l)e an atom truly formidable, in every sense of 

 the word, as the lerist friction must be supposed capable of pro- 

 ducing a violent explosion of such a mass of elasticity. I cannot, 

 however, doubt that Dr. Berzelius, having resumed the considera- 

 tion, will very soon discover and acknowledge that his analysis is 

 incorrect. In the mean time, T shall give my reasons fur believing 

 it to be so. 



Dr. B. informs us in the Ann. dc Chim. (tom. 81, p. 300) that 

 10 grains of oxalate of lead yielded by heat 7"42 of yellow oxide. 

 Hence he infers the constitution of oxalate of lead to be 25*2 acid 



