ANALYSIS OF VEGETABLE AND ANEMAL SUBSTANCES. (yQ 



retted hidrdgen they may cont;fin ; and thu? we acquire a 

 certainty, that they no longer consist of any thinsj but dar- 

 boiiic acid and oxigen, the sep/iration of which is to be efr 

 fected by means of potush. 



But this ntcessity of raisiUj; the temperature so high, Farther pie- 

 pbliges us, on the other hand,' to take some precautions for 

 preventing the co«-k from being heated. For this purpose 

 the glass tube is passed thrt^isgh a brick, into which it is 

 luted with clay, which ha? ih<^ advantage, at the same time, 

 of rendering the apparatus fij-m ; and besides, a suiall hol- 

 low cylinder is soldered to the body of the cpcl^^ tp contain 

 water, or ice, which isatill better. 



Thus we have all the necessary data for knowing the pro- Data, 

 portion of the principles of the vegetable substance. We 

 know how much of it has been buMied, for we have its 

 weight to half a milligramrpe, [about eight thousandths of ^ 

 grain]; v.e know how much oxigen was required to convert 

 it into water and carbonic ncid, since the quantity is the dif- 

 feitence between that contained in the hyperosimuriate and 

 that found in the gasses produced : lastly, we know how 

 much carbonic acid has been formed, and can qalculate hovy 

 much water must have Ijeen produced. 



By following the same raetiiod of analysis, we may equally Analysis of 

 determine the proporti-jns of the constituent principles <>f stances^" 

 all animal substances. But as these substances contain ni- 

 trogen ; and nitrous acid gas would be formed, if an excess 

 of hyperoximuriate were emf>loyed for burning {hem ; only 

 such a quantity must be used, as is sufficient to reduce them 

 completely to carbonic acid gas, oxicurburetted hidrogen, 

 and nitrogen, which fire to be analysed in the mercu'- ul 

 eudiometer by the common methods, whence we deduce 

 with precision the piioportions of the principles of the ani- 

 inal substance itself. 



The mode in whi^ph we proceed in the analysis of vegetable Smrll quanti- 



and animal substances bein^ exactly known, we may say ^]^^ '^'^']' 



° - , ' _ . . ^'^s c^sults ao 



what is the quantity we decompose, without fear of diuji- curate. 



nishing the reliance, that may be placed on our results. 



This quantity extended, at most, to 6 dec. [9*27 grs.] If, 



however, the least doubt should arise respecting their exr 



freme accuracy, \jie should remove it by observing, that we 



filled 



