Chemical arid Physical Papers. 43 



RECENT METHODS IN ELEMENTARY ORGANIC 

 ANALYSIS. 



(Abstract.) 



O. S. Groner. Ottawa University. Ottawa. 



TN THE paper a careful study was made of the Dennstedt, Morse 

 and Walker methods of determining carbon, hydrogen and 

 nitrogen in organic compounds. In the Dennstedt method (com- 

 pare Ber. d. Deut. Chem. Ges , vol. 30, p. 1590; vol. 38, p. 3729; 

 vol. 39, p. 1623; Dennstedt's Anleitung zur Vereinfachten Elemen- 

 taranalyse) three applications of chlorplatinic acid were found 

 necessary in order to prepare the quartz properly for the combus- 

 tions. The results on nitrogen, which is determined simultaneously 

 with the carbon and hydrogen by absorbing the nitrogen tetroxide 

 with lead dioxide and weighing as lead nitrate, were low, and there 

 is evidently greater difficulty in obtaining concordant results than 

 by the other two methods. 



The Morse method was carried out as described by the author 

 (Am. Chem. J., vol, 33, p 457; Exercises in Quan, Chemistry, p. 

 457, H. N. Morse). The objectionable feature is that it does not 

 permit of the determination of nitrogen. 



In the history of chemical science no portion is of greater in- 

 terest than the one which concerns itself with the development of 

 our present system of elementary organic analysis. 



Lavoisier was the first chemist to reduce the subject to a quan- 

 titative basis. By his experiments he established the true prin- 

 ciples of combustion, which furnished a basis for the determination 

 of the composition of organic compounds. Working on the prin- 

 ciple that oxygen united with carbon and hydrogen to form per- 

 manent compounds, Lavoisier succeeded in determining the 

 quantitative composition of some organic compounds. His first 

 work was done with crude apparatus, but his results were quite ac- 

 curate, when the process which he employed is taken into consid- 

 eration. Lavoisier improved his methods very rapidly and devised 

 methods which are very similar to those in use at the present time. 

 He succeeded in analyzing substances which were difficult to burn, 

 and obtained good results. 



It would be difficult to estimate too highly the significance of 

 his work. He established the fundamental principles of elementary 



