402 MR. R. RIGG'S EXPERIMENTS ON NITROGEN IN VEGETABLE PRODUCTS. 



process, those which are embodied in this paper may be considered as approximating 

 to an average of the whole, as regards both this gaseous element and the incombus- 

 tible matter. 



In conclusion, I would observe that the mode of analysis which I have adopted in 

 the examination of organic compounds, so far as determining the quantity of carbon, 

 hydrogen, oxygen, and residual are concerned, is the one described in the paper on 

 vegetable decomposition to which I have already referred. Respecting the mode of 

 determining the quantity of nitrogen, a very brief account of the plan which I have 

 adopted is given in the Philosophical Magazine for January last ; and by combining 

 these two methods of ultimate analysis, I am enabled, in recapitulation, to detect very 

 minute errors, and therefore to speak with certainty as to the accuracy and value of 

 every experiment. 



