488 PROCEEDINGS OP THE AMERICAN ACADEMY 



11. ON THE DECOMPOSITION OF WOOD AT HIGH 



TEMPERATURES. 



By Henry B. Hill and Arthur M. Comey. 



Although preliminary experiments had shown that gaseous products 

 of decomposition were formed from wood in considerable quantity only 

 at comparatively high temperatures, it seemed to us of interest to follow 

 the reaction more closely, and to determine quantitatively the extent 

 of the decomposition at various temperatures. Since the investigation 

 was originally undertaken to determine whether this decomposition 

 had any practical importance, it also seemed advisable to select the 

 conditions usually met with in practice, and to heat the wood in a 

 slow current of air rather than in vacuo or in a current of an inert gas. 

 Since volatile products were formed in but small quantities, it was 

 useless to attempt any separation or identification of them other than 

 the discrimination between the carbonic dioxide directly formed and 

 the carbon volatilized in other forms. The carbonic dioxide we de- 

 termined by absorption in a standard solution of baric hydrate, and 

 the volatile carbon by the same method after combustion with copper 

 oxide. The method we employed was as follows. A definite weight 

 of wood in the form of small fragments was introduced into a glass 

 tube and heated in an air-bath to the requisite temperature. Through 

 the tube was then drawn a slow current of air, which had been freed 

 from volatile carbon compounds and carbonic dioxide by passing over 

 red-hot copper oxide and washing with potassic hydrate. A wash- 

 bottle filled with a concentrated solution of baric hydrate, through 

 which the air passed in entering the tube, served to prove the complete 

 removal of the carbonic dioxide. On leaving the tube, the air passed 

 through a measured quantity of a baric hydrate solution of known 

 strength, and the complete absorption of the carbonic dioxide was 

 proved as before by means of a wash-bottle containing a stronger solu- 

 tion of baric hydrate. The air thus freed from carbonic dioxide was 

 led over a small roll of copper gauze heated to redness, and the car- 

 bonic dioxide thus formed absoi'bed as before in a measured quantity 

 of a standard solution of baric hydrate, while a second wash-bottle 

 with baric hydrate served to control the absorption. After the lapse 

 of a sufficient time, the amount of carbonic dioxide directly formed, 

 and that formed by the combustion of the volatile carbon compounds 

 was determined by titration of the baric hydrate solutions with oxalic 



