1823.] Vegetable and Animal Substances. 351 



dried. A note of interrogation is placed after azote. That 

 doubt will I trust be solved, when I complete my analyses of 

 grains, roots, and leaves, with the view of tracing the origin of 



azote in the bodies of graminivorous animals With regard 



to resin, 1 believe the quantity of its carbon to be somewhat 

 underrated in the table. Though three experiments were made 

 on it, I now perceive that 1 had omitted to retriturate and 

 reignite ; and the carbon of resin is very difficult of oxygenation. 

 Its true composition is probably, carbon, 8 atoms ; hydrogen, 8 ; 

 oxygen, 1. A still more symmetric arrangement would be 

 derived from carbon, 8 atoms ; hydrogen, 9 ; oxygen, 1 . This 

 proportion corresponds to 8 atoms of defiant gas and 1 atom of 

 water ; and I think it is very possibly the true constitution of 

 resin. Had the loss of weight suffered by the contents of the 

 tube, during their ignition, been a few hundredth parts of a 

 grain more, the experimental result would have coincided with 

 this theoretical view. Copal approaches to carbon, 10 atoms ; 

 hydrogen, 7 ; oxygen, 1. Lac may be nearly represented by 

 carbon, 6 atoms ; hydrogen, 4 ; oxygen, 2 ; or 2 atoms of ole- 



fiant gas + 1 atom carbonic oxide Resin of guaiac gives 



carbon, 7 atoms ; hydrogen, 4 ; oxygen, 2." 



" Although the experiments on amber were conducted care- 

 fully with retrituration and reignition, no good atomic configura- 

 tion of it has occurred to me. It approaches to 10 carbon + 

 10 hydrogen + 2 oxygen." 



" Wax is apparently composed of carbon, 13 atoms ; hydro- 

 gen, 11; oxygen, 1 ; or, in other words, of 11 atoms defiant gas 

 + 1 atom carbonic oxide + 1 atom carbon. Had the experi- 

 ment given a very little more hydrogen, we should have had 

 wax as consisting of 12 atoms defiant gas + 1 atom carbonic 

 oxide. This is possibly the true constitution." 



"Caoutchouc seems to consist of carbon, 3 atoms; hydrogen, 2; 

 or it is a sesqui-carburetted hydrogen. The oxygen deduced 

 from experiment is in such small quantity, as to leave a doubt 

 whether it be essential to this body, or imbibed in minute 

 quantity from the air during its consolidation." 



" Splent or slate coal, specific gravity 1*266, abstracting its 

 incombustible ashes, approaches in constitution, to carbon, 

 7 atoms ; hydrogen, 3; oxygen, 2. Cannel coal from Woodhall, 

 near Glasgow, specific gravity 1*228, resembles a compound of 

 carbon, 9 atoms; hydrogen, 3; oxygen, 2. In both of these 

 bodies, there is an excess of carbon beyond the 3 atoins of ole- 

 fiant gas and 2 of carbonic oxide. The former coal has 2 extra 

 atoms of carbon, and the latter, 4 atoms. Hence this coal is 

 found at the Glasgow gas works to yield a very rich burning 



S as \ 



" The elements of indigo may be grouped as follows : carbon, 



16 atoms ; hydrogen, 6 ; oxygen, 2 ; azote, 1 ; or, in other 



