328 



Dr. Thcmson on the true Weight of 



[Nov. 



Barytes 



Potash 



Soda 



Protoxide of lead. 

 Sulphuric acid. . . 



Nitric acid 



Muriatic acid . . . 

 Chromic acid . . . 



D.iltoii. 



7128 



9 



6-000 



4-000 



14-571? 



4-8571 

 2-7128 

 3-1285 



Wiillaslon. 



9-7 

 5-91 

 3-91 

 14-00 

 5-00 

 6-754 

 4-542 



Berzelius. 



19-1386 



11-7983 

 7-8184 



27-8900 

 5-0116 

 6-7726 

 3-4265 



13-0364 



TliomsoD. 



9-75 

 6-0 

 4-0 

 14-0 

 6-0 

 6-75 

 4-625 

 6-5 



BerzeHus's numbers appear, to differ more from those of Dr. 

 Wollastoii and my own than is really the case ; because both 

 Dr. WoUaston and myself have expressed the atomic ratios in 

 the lowest terms or nearly so ; while Berzelius, from certain 

 notions which he entertains respecting the number of atoms of 

 oxygen which unite with the respective bases, has very frequently 

 raised his ratios to higher numbers than would be otherwise 

 requisite. It is not yet quite time to enter into a discussion 

 respecting Berzelius's opinions on this subject, though the 

 period is fast approaching when such a discussion would be 

 attended with advantage. Mean while I may just observe that 

 ail which we know, or ever can know, respecting the weights of 

 the atoms of bodies, is the ratio which they bear to each other. 

 Now every person in the least conversant with number* must 

 see that the lower the terms in which these ratios are expressed 

 so much the more advantageous are they both for the memory 

 and for comparing them with each other. On this account, I 

 think, it would have been better if both Wollaston and Berzelius 

 had represented the weight of an atom of oxygen by unity, as I 

 have done, than by 10, or 100, the numbers which they have 

 respectively employed. I find at least that I can remember the 

 small numbers which I have affixed to the atoms of bodies more 

 easily than those given either by Dr. Wollaston, or by Professor 

 Berzelius. 



When the numbers of Berzelius are brought to their lowest 

 terms, they are as follows : 



Barytes 9-5693 



Potash 5-89915 



Soda 3-9092 



Protoxide of lead 13-9450 



Sulphuric acid 5-01 16 



Nitric acid 6-7726 



Muriatic acid 3-4265 



Chromic acid 6*5182 



Now these numbers, though not one of them be absolutely the 

 same as mine, do not deviate very far from them. The atomic 



