529 



only answer with such fuels as anthracite, which contains 

 very little hydrogen, but with those it succeeded perfectly. 



Such were the means taken for the organic elementary 

 analysis. The nitrogen was not separately determined, as 

 the results were only required for economic calculations, 

 and the minute trace of nitrogen does not there become impor- 

 tant. Its weight (in all cases very small) is included in the 

 number assigned to oxygen in the results of the analyses. 



The practical analysis was conducted by very strongly 

 igniting a weighed portion of the fuel in a platinum crucible 

 the cover of which fitted so closely as to prevent any sensi- 

 ble combustion of the residual coke. The weight of ashes 

 being known, the pure coke was then found. 



The determination of the reducing power of the fuel by 

 means of litharge, requires very considerable care in prac- 

 tice in order to get satisfactory results. The principal point 

 to be attended to, is to use a roomy crucible, and to apply a 

 quick and strong heat, so that the Mtharge shall at once run 

 thin. When this is done, the results with the same fuel are 

 very uniform, and with different fuels are fully comparable ; 

 although in no case is so much lead got as should be in 

 theory obtained from the conversion of the carbon and 

 hydrogen of the fuel, minus its oxygen, into carbonic acid 

 and water. The deficiency is usually proportional to the 

 quantity of volatile matter in the fuel, and is not in any case 

 large, provided proper care be taken. Hence Dr. Kane 

 considers, and the opinion is also held by Berthier, that the 

 result is so near the truth as to be quite available as a prac- 

 tical and ready measure of the heating power of the fuel. 



The general nature of the inquiry, and the methods em- 

 ployed, having been thus described, it is only necessary to 

 add the numerical results of the analysis. 



In order that the results might represent as far as prac- 

 ticable the average composition of the fuel, in each case 

 rather a large mass was broken up, and its coarse powder 

 2y2 



