438 Dr. Thomson's Observations on the Weights of [Dec. 



Number of atoms. 



138 Nitric acid , 



139 Chloride of azote , 



140 Sulphuret of potassium. 



141 Sulphuret of sodium. ...... 



142 Protosulphuret of iron 



143 Persulphuret of iron , 



144 Sulphuret of cobalt 



145 Sulphuret of zinc 



146 Protosulphuret of bismuth . 



147 Persulphuret of bismuth . . 



148 Protosulphuret of lead. . . . 



149 Persulphuret of lead 



150 Protosulphuret of tin 



151 Persulphuret of tin , 



152 Sulphuret of copper 



153 Protosulphuret of mercury . 



154 Persulphuret of mercury . . 



155 Sulphuret of silver 



156 Sulphuret of gold 



157 Sulphuret of palladium. 



158 Oxalic acid. // + 



159 Fonnic acid 1 h + 



160 Mellitic acid 1 h + 



161 Succinic acid 2 h + 



162 Acetic acid 3 h + 



163 Citric acid 3 h + 



164 Tartaric acid 3 h + 



165 Gallic acid 3 h + 



166 Tannin 3 h + 



167 Saclactic acid 5 h + 



168 Benzoic acid 6 h + 



a + 



a + 



P + 



so + 



i + 



i + 



c + 



z + 



in + 

 m + 

 si + 



g + 

 P + 



2 c 



2 

 4 

 4 

 4 

 4 

 4 

 6 

 6 

 6 

 15 



5 

 4 

 1 

 1 

 1 

 2 

 1 

 1 

 1 

 2 

 1 

 2 

 1 

 2 

 1 

 1 

 2 

 1 

 1 

 1 



+ 

 + 



+ 

 + 

 + 

 + 

 + 

 + 

 + 

 + 



o 



ch 



s 



s 



s 



s 



s 



s 



s 



s 



s 



s 



s 



s 



s 



s 



s 



s 



s 



s 



3 



3 



3 



3 



3 



4 



5 



3 



4 



8 



3 



Weight of 

 a particle. 



6-750 



19-750 



7-000 



5-000 



5-500 



7-500 



5-625 



6-125 



10-875 



12-875 



15-000 



17-000 



9-375 



11-375 



10-000 



27-000 



29:000 



15-750 



11-250 



9-000 



4-500 



4-625 



6-125 



. 6-250 



, 6-375 



7-375 



, 8-375 



, 7-875 



. 8-875 



, 13-125 



. 15-000 b 



b These numbers are the results of the analyses of Berzelius, 

 with the exception of oxalic acid. Berzelius states the amount 

 of the hydrogen in this acid at -r^-th of an atom. It being obvious 

 that such a combination cannot exist, I have left out the hydrogen 

 till the point can be more accurately determined. 



It is scarcely necessary to remark that the mere knowledge of 

 the number of atoms of which a vegetable body is composed 

 cannot lead to an accurate idea of its constitution. The proba- 

 bility is that these atoms do not unite altogether to form the 

 vegetable body in question ; but that they enter in the rirst 

 place into binary or ternaiy combinations, and that these primary 

 compounds, by uniting with each other, form the vegetable sub- 

 stance in question. Thus we may conceive oxalic acid to be a 

 compound of one atom of carbonic oxide with one atom of cai> 



