248 Remarks on a Paper by Mr. Daltcn 



mixing two measures of nitrous gas with one of oxygen. This 

 shows that the one measure of oxygen contains twice as many 

 particles as there are atoms in two measures of nitrous gas. This 

 was one of the many facts which led me originally to the doc- 

 trine of definite proportions — that beautiful law by which oxygen 

 unites to bodies in different doses, and that the 2d, 3d, 4th, and 

 5th were all distinct multiples of the first or minimum dose. 



In producing the pale nitrous acid by mixing oxygen and 

 nitrous gas, there are sometimes formed atoms of the red nitrous 

 acid mixed with the pale, therefore less oxygen is consumed ; 

 and again, particles of nitric acid are formed, which demand 

 more oxygen, and which only mix with the pale ; — in these cases 

 different quantities of oxygen are consumed by the nitrous gas. 

 The foregoing variations depend upon the manner in which the 

 gases are mixed, and the surface which they present to water. 



These facts will account for the difference of opinion enter- 

 tained by chemists respecting the proportions in which the two 

 gases unite so as to form, according to them, the same acid. 



The fifth and last combination of those elements is the nitric, 

 which I called in my Comparative View the colourless nitrous 

 acid, as being when perfectly pure as limpid as distilled water. 



Mr. Dalton represents this as composed of 100 measures of 

 azote and 310 of oxygen: this quantity should give more than 

 six ultimate particles of oxygen to each particle of the azote. 

 His symbol gives only five, with the extraordinary proportion of 

 two of azote : — whence comes the second particle of azote is best 

 known to Mr. Dalton himself; 1 cannot make it out, 1 must 

 own. 



In mv Comparative View I represented the atoms of this acid 

 as consisting of one particle of azote and five of oxygen. My 

 definite proportions of the different compounds which those 

 elements are capable of forming, are as follow : 



Nitrous oxide . . . . I and 1. 

 Nitrous gas , . . . 1 and 2. 



Red nitrous acid . . . . 1 and 3. 

 Pale nitrous acid . . . . I and 4. 

 Nitric acid . . . . 1 and 5. 



The variation of the different forces of attraction according 

 to the quantum of oxygen was also stated, which is the most im- 

 portant part of the whole system, and which alone could enable 

 me to account for the following facts ; viz. 



1 and 1 will have no effect on 1 and 2. 

 1 and 2 will not affect . . ) and 3. 



1 and 3 no effect on . . . , 1 and 4 . 

 1 and 4 no effect on . . . . 1 and 5. 

 They will only mix mechanically. 



On 



