

1814.] Elements of Organic Nahre are coinl'med. 403 



one of the principal of these ; I n ..ie discovery of the relation 

 between the volumes of gasiform bodies that combine together. 



I -shall now state what I have c oe myself in this kind of analysis. 

 In the year 1807, during mj first experiments on determinate pro- 

 portions in chemistry, which were suggested to me by the excellent 

 experiments of Richer v Lber die neilen getrenstande der Chimie, 

 st. ix. and x.), at a period when I did not fi lie extent of the 



■subject, I formed the resolution to analyse the vegetable acids with 

 more care than my predecessors, beginning with acetic acid, whose 

 capacity of saturation I had already ascertah c; 1 . 1 attempted this 

 analysis by distilling a mixture of cfllorcsecd acetate of lime and 

 minium. I obtained in different experiments quantities of water 

 nearly equal; but the carbonic acid, which was absorbed by barytes 

 water, varied considerably, on account of the product ion of car- 

 bonic oxide, which 1 could not prevent. This led me to abandon 

 the experiment. 



But after 1 had examined a great number of inorganic bodies, I 

 thought it requisite to return to organic substances, in order to 

 determine how far the laws which 1 had ascertained in inorganic 

 nature would apply also to organic bodies. 



I analysed at that time oxalic and tartaric acids, and I gave an 

 account of the results which 1 obtained in Gilbert's "Annalen der 

 Physik, February, 1812; and in the Annales de Chimie, May, 

 June, &c. 1812. To perform these analyses 1 mixed the oxalate or 

 tartrate of lead with the brown oxide of lead, and distilled the mix- 

 ture, making the gases evolved pass through a tube filled with 

 muriate of lime. The carbonic acid gas was absorbed by lime- 

 water ; so that the carbonate of lime formed could be collected and 

 weighed. By this method I obtained the water and carbonic acid 

 with sufficient precision to enable me to calculate the hydrogen 

 and carbon in the acids. The loss was oxygen; and if this was a 

 multiple by a whole number of that in the oxide of lead combined 

 with the acid, 1 considered my analysis as correct. 



But this method of analysis had inconveniences which rendered 

 it less exact. The decomposition took place with too much rapi- 

 dity, so that it was difficult to keep the joinings air-tight; and it 

 always gives a little more carbon and hydrogen than die substance 

 analysed contained, which rendered the proportion of oxygen too 

 small, as may be seed by the results of these analyses laid before 

 the public. I found a method of correcting the first of these incon- 

 veniences, by putting the mixture to be burnt in a tube, and heating 

 only a part of this tube at a dote, commencing at the open extre- 

 mity, and proceeding gradually to the shut end. But 1 found it 

 impos-ible to correct the errors in the result, because the red lead 

 from which 1 prepared my brown oxide contained always some 

 impurities, which I could not remove, and which remained mixed 

 with the brown oxide ; mi that this oxide, when decomposed alone 

 by heat, gave always traces of moisture and carbonic acid : 



In contequctx* of this 1 pul oil' again the experiments on 



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