Manchester Memoirs, Vol. lix. (191 5), No. \%. 59 



above as similarly constituted, but with six vegetable 

 atoms. 



Sheets 25 to 28 seem to belong to the same period 

 and were found together, apart from all the other sheets 

 described here. 



Sheet 29. 



Formulae equivalent to CHO (acetic acid, or "vegetable 

 atom ") and C 4 H 3 3 , the latter being a central carbon 

 atom surrounded by three "vegetable atoms." This may 

 represent one of the acids above mentioned, or possibly 

 the atom of sugar, or of wood. Dalton represented sugar 

 on various occasions as a central carbon atom with 5, 8, 

 and 12 "vegetable atoms "around it. 



Sheet 30. 



Formula, entitled " indigo." Equivalent to C 8 H. 2 ON. 

 In his paper on the " Nature and Properties of Indigo" 

 {Mem. y 1824, 9, 427) Dalton arrived at this composition 

 from Crum's analysis, with Dalton's own atomic weights. 



Sheet 31. 



Formula, entitled "oil etc." and described : 



Gay Lussac. 

 777 77"2 

 94 

 13-4" 



" Carb. 

 Oxy. 

 Hyd. 



9-2 



" Olive oil and probably 



Spermaceti oil." 

 " Constitution 



r atom Carbonic oxide. 

 10 atoms olefiant gas." 



This constitution is found in the Laboratory Note- 

 book iv., p. 58 (181 1). Earlier suggested formulae are to 

 to found, but are different from that of this sheet. 



Sheet 32. 



The atoms C 8 H 2 ON arranged as a molecule. Below 

 is written in Dalton's handwriting: 



