224 MEMOIR OF DR. DALTON, AND 



were oxides which had been sulphuretted. The object of my 

 work has been to show the fallacy of this, and that we must 

 give up these sulphuretted oxides, which we admit, without 

 proof, and receive in their place a species of combination, 

 new, without doubt, but well demonstrated. Certainly 

 this combination is in opposition to the ideas of Berthollet ; 

 he wishes to place them in the family of sulphuretted oxides, 

 but it is no less certain, that those which I have announced 

 do exist, and that they have this advantage over sulphuretted 

 oxides, the existence of which is now terminated, that they 

 afford the most natural solution of those thousand and one 

 problems in antimony, the ridiculous nomenclature of which 

 has shown the confusion of our ideas, and covered with 

 obscurity the history of that metal." 



Page 264. " To a lib. of potash you add an ounce of arsenic; 

 it is not saturated, you add two, you add three, it is not yet 

 saturated, and so with more; but in waiting to discover the 

 point of saturation, I repeat to them ; your arsenical potashes 

 are nothing at present but potash, plus one, two, or three of 

 arsenic, but we have not time to prove that this combination 

 will obey, as it no doubt will, the law of proportion, and shall 

 not press you to decide on it. These are results so variable 

 that they destroy your laws of proportions, and render your 

 apothegms illusory. Berthollet is too just not to agree that 

 the series of numbers by which I have sought to represent 

 the solutions of the sulphuret of antimony in its oxide, has not 

 the least relation to that which I. have hitherto called pro- 

 portion in combinations." 



Journal de Physique, 1805, vol. lix., page 321. 



" Sur les Oxidations Metalliques." 



" I ought to explain, says Berthollet, that the proportions 

 of oxygen may vary progressively after the limit or the com- 

 bination becomes possible, until it attains the last degree; 

 and when this does not take place, it is because the conditions 



