144 ATOMIC PRINCIPLES Ot CHEMISTRY. 



atomic system divided into two parts; one of which relates principally to 

 the theory of cliemical combinations, which 1 have embraced 

 from an extensive comparison of facts and observations fur» 

 nibbed by the writings of others, and from a careful and 

 laborious train of ex})eninental investigation of my own ; the 

 other relates to liis application of the theory to the solution 

 of a few of the more simple and common combinations. On 

 the former of these parts I beg leave to make a few observa- 

 tions r on the latter 1 think it is altogether unnecessary to 

 say any thing, unless it be to correct a iijisrepresentation 

 or two whi<?h Dr. Bostock has accidentally introduced, 

 namely, that oxigen and hidrogen in water are as 85*7 to 

 14'3 in weight, and that these numbers are as 7 to 1 nearly 

 (page 285) ; and that 1 conceive nitrous oxide to be a binary 

 compound (page 290). The weights of oxigen and hi- 

 drogen in water are stated (vid. New Syst. p. 275) to be 

 fe7*4 and 12*6 respectively ; and it is nitrous gas which I 

 maintain to be binary^ and nitrous oxide and nitric acid to 

 be ternary compounds. 

 Meaning of I do not exactly agree with Dr. Bostock as to his remarks 



th« terms, ^^^ ^^^ difference between theory and hypothesis] these 

 Boihesis. terms as far as I can learn from their common use differ 



only in degree. Theory is all or the greatest part of the 

 facts reduced to regular laws; hypothesis is where only a 

 few facts are reduced to laws, and the rest are either irre- 

 ducible, or are yet only in a train, or have their accuracy 

 Jiuspected, I think no one would seriously advance "any 

 hypothfcciis on any subject, that hud not some one or 

 oaore facts previously established in its favour. What is 

 theory to one man may be hypothesis to another. If 

 Newton had lived in an age when no malheinatician bnt 

 himself existed, he might have established his beantil'ul 

 theory of gravitation to his own satisfaction ; but it must 

 have been only an hypothesis to the rest of his contempo- 

 raries. These observations lead me to remark farther, 

 •that my chemical doctrine on combination is not, ** alto- 

 gether hypothetical," according to Dr. Bostock*s own 

 definition. I remember the strong impression which at a 

 very early period of th«'se inquiries was made b}'^ observing 

 the proportion of^xigen to a^ote, as 1,2 and 3, in nitrous 



oxide. 



