pouudd, neutralizing the basts with which it is in combiun* 



tion ; in the same manner as I consider real sulphuric op ni^- 



trie ncid as an acid from knowing, that they exist in cjpmbii* -jiitt j.taff 



nations free or nearly so from water, exerting « similar new* '"' "^ " "^ "' ^ 



Iralixing power* Mr. DaVy may if he pleases suppose sul* 



phuric or nitiid acid to be a compound of an unknowiii 



basis and water, and conclude, that the supposition of the 



existence of these acids free from water is "speculation in 



the strictest sense of the word*'* But no chemist will fnrd 



any difficulty in this. The apparently greater influence of 



tvater on the chemical powers of muriatic acid than the 



Other acids probably arises from the facts with regard to 



the latter being more fully developed. On this subject I 



»m at present engaged in an experimental investigation. 



Mr. Davy proceeds to examine the objections which I haid Isiproba^iVi'^ 

 cyffered to his brothet*s opinion. To the remark, that "L^'^^^'f'.^J 

 there is some improbability in the hypothesis of two acidic 

 fying principles, he replies, that the only legitimate mode of 

 reasoning is induction ; and that we are not to judj^ of Mr* 

 Davy's views by considsring their probability or improbabi- 

 lity a priori, but by a reference to facts. Tiie observation 

 would be just, were Mr. Davy's opinion a theory ; but 

 ^while it is an hypothesis the objection retains its force> for 

 of two hypotheses proposed op any subject, it is fair in con- 

 trasting them to bring into view the probability a priori of 

 the principle of the one compared with that of the other*, 

 The concession that he makes, that there is properly qo 

 acidifying principle, is rather more in point, and I h«ve re- 

 marked in my Elements of Chemistry, in giving a view of 

 the theory of acidity, that the supposition of acidity being u 

 property rather derived from the base of acids than from p^rWs noft«- 

 their common principle is most conformable to Mr. Davy's 

 speculations. Still the similarity of oximuriatic acid to 

 oxigen so as to class them as acidifying principles is very 

 remote; for allowing it to combine directly with any sub» 

 stance, it forms no acid in the common definition of the 

 term, or any substance analogous to acids, but in its sup- 

 posed combination with hidrogen, the subject of dispute; 

 and the acidity of this, and its analogy to the common acids, 

 •re indeed such as to atJord on the other iwmd as striking on 



AnonoLttlv 



