418 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



tions involved in the process are as follows : One of the low- 

 er retorts is charged with one hnndred and fifty pounds 

 of ordinary cord-wood, and as soon as gas begins to be 

 evolved which is almost instantly by means of suitably 

 arranged pipes and valves, the w^ood-gas is thrown into the 

 upper retort, in which it comes in contact with the heavy 

 vapors evolved from the petroleum. The two gases thus 

 commingled are then passed over a lengthened heated sur- 

 face, the resultant product being a fixed or permanent gas of 

 any desired illuminating power, leaving little or no residuum. 

 The charcoal resulting from the process is declared to more 

 than pay for the W'Ood employed. 17 Z>, XX., 32. 



SULPHUR I]Sr COAL-GAS. 



To estimate rapidly the amount of this impurity existing 

 in illuminating-gas, Mr. Vernon Harcourt proposes to pass 

 the gas through a flask filled with small pebbles, kept at a 

 low red-heat, by which the sulphur present as bisulphide of 

 carbon is decomposed into sulphuretted hydrogen ; a known 

 volume of the gas is then passed through a solution contain- 

 ing a lead salt of given strength, and the depth of coloration 

 produced is compared Avith a standard set of colors, by w^iich 

 the percentage of sulphur is obtained. Proceedings British 

 Association^ 1875. 



ILLUMINATING-GAS FROM NIGHT-SOIL AND DEAD ANIMALS. 



As the conversion of refuse animal matter into illuminants 

 has often been suggested as a practical method of solving a 

 troublesome sanitary problem, it is of interest to record the 

 experience of Professor Troschel, director of the gas-works 

 at Breslau, in Prussia, with an improved process of this nat- 

 ure lately invented by A. Sinderman. The Sinderman sys- 

 tem, having been favorably reported upon by a committee 

 selected by the city authorities, was introduced upon a work- 

 ing scale, and subjected to a careful investigation as to the 

 quality of gas produced and its cost, and with the following 

 results : The quantity of gas j^roduced from a given weight 

 of material was found to be considerably less than from the 

 same weight of coal, so much so that, for the production of 

 equal quantities, the new works would demand about twice 

 the capacity of the old system with coal. The expense of 



