170 On the Daltonian Theory of [Sept. 



Number of Weight of an 



atoms. integrant particle. 



1 n + 1 to 5-010 



l?i + 2 w 6*1-12 



1 n + 3 iu 7-274 



1 i + 1 w 9-798 5 



150. 2d hydrate of nitric") 

 acid, or acid of 1 "54 . . J 



151. 3d hydrate of nitric") 

 acid, or acid of 1 -42 . . J 



152. 4th hydrate of nitric! 

 acid, or acid of 1*350 J 



153.Hydrophosphorousacid2 p + 1 w 5 '772 p 



1 51-. Hydrate of boracic acid 1 b + 3 w 9-106 1 



155. Hydrate ofperoxide\ \ c ±. \ w 11*132 r 



of copper J 



156. Hydrate of black \ 

 oxide of iron J 



157. Hydrate of red\ xi + l w 10 . 798 * 



oxide or iron j 



158. Hydrate of deut-7 , t , , „„ ,w >fi( , ?u 

 ■ i J r .- J> 1 r + 1 w . . . . .17 837 



oxide ot tin \ 



by Da I ton. The reader may consult his curious table in his 

 JSfetv System of Chemical Philosophy, Part II. p. 3.55. 



p This is the result of the experiments of Sir Humphry Davy, 

 who, by combining phosphorous acid with ammonia, and dis- 

 tilling off the water, found that the hydrate of phosphorous acid 

 is a compound of 2 integrant particles of phosphorous acid and 

 1 ofwater. {Davy's Elements of Chemical Philosophy, p. 289.) 



i We shall see afterwards that the weight of an integrant 

 particle of boracic acid is about 5*710. Now Davy found 

 hydrate of boracic acid composed of about 57 acid 4- 43 water. 

 This approaches the number in the table; but as it does not 

 quite correspond, little confidence can be put in it. 



r This is the blue substance obtained by precipitating nitrate 

 or sulphate of copper by an alkali. According to Davy, it is 

 composed of 9 peroxide of copper + 1 water. Now 9 : 1 :: 10 

 : 1*111; and 1*111 is very nearly the weight of an integrant 

 particle of water. 



s It appears from my experiments that water combines with 

 black oxide of iron. I state the proportions from analogy merely. 

 The increase of weight in my trial was rather less than equivalent 

 to the proportion of water stated in the table. 



1 This is the orange precipitate obtained from oxysulphate of 

 iron by an alkali. It has been ascertained to be a hydrate, but 

 never analysed. I state the proportions merely from analogy. 



u This the white powder obtained by precipitating the recent 

 solution of tin iu muriatic acid. According to Proust, it is 



