524 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



tanks) in which grease is rendered. All this material has 

 heretofore been either wasted, or the attempts to utilize it 

 have been so crude and ineffectual as to make the business 

 not worth pursuing. At the present time, about New York, 

 Chicago, Cincinnati, and Baltimore, a large amount of capital 

 is employed, with machinery and skilled labor, by which 

 many thousands of tons of dry, inodorous, nitrogenous mat- 

 ter is prepared and put in the market. It is sold readily at 

 wholesale at about $3 75 for each unit of ammonia in a ton; 

 e. g., such as contains 10 per cent, sells at $37 50 per ton. It 

 is bought by makers of fertilizers to furnish the proper pro- 

 portion of ammonia in their compounds, and preference is 

 said to be given to it over the Peruvian guano, which w r as 

 formerly used for that purpose. In this case the buyer pays 

 for only the actual ammonia contained in the dried meat, 

 while the price for Peruvian guano is uniform, though the 

 quality is variable. 



UTILIZATION OF THE REFUSE FROM SCOURING WOOL. 



For this purpose, according to Chaudet, sulphurous acid is 

 introduced directly into the greasy w T ater resulting from the 

 operation until it is acidified ; it is then allowed to stand for 

 twenty-four hours, when an upper layer of impure fat, a mid- 

 dle one containing compounds of sulphurous acid with soda, 

 potash, and ammonia, and a lower one of earthy sediment, will 

 be found. The residue from the evaporation of the middle 

 layer is to be ignited in a reverberatory furnace, to convert 

 the sulphites into sulphates, which are dissolved out and 

 crystallized. The upper layer is to be pressed through bags 

 while hot, to obtain the fatty acids. 14 C\ 1873, 465. 



DETECTION OF FUCHSINE. 



Fuchsine, one of the so-called coal-tar colors, is sometimes 

 used in the adulteration of w T ine and liquors, and also for 

 tinting bonbons. Being a deleterious substance, its detec- 

 tion is sometimes to be attempted, and the following method 

 has been proposed by Doray. The suspected liquid is to be 

 shaken violently in a flask with a mixture of two parts of 

 benzine and three of carbolic acid. After standing quietly 

 for a few moments, the two liquids of different density sep- 

 arate, the upper layer carrying with it the fuchsine in solu- 



