M. TECHNOLOGY. 523 



pletely disintegrating it. A doughy mass is then formed by 

 stirring slaked lime into the gelatinous liquid, and distilling 

 this, at as low a temperature as possible, in an iron retort, 

 supplied with receivers containing oil of vitriol. When the 

 evolution of gas has ceased, the retort is finally to be heated 

 to redness. The white residual powder in the retort, consist- 

 in^ of carbonate of soda and caustic lime, on treatment with 

 water, affords caustic soda, which may be used to renew the 

 operation. 14 C, CCIX., 156. 



EXTRACTION OF SILK FROM HALF-SILK RAGS, ETC. 



Hitherto only all-silk material has been worked over, but 

 Dr. Wagner claims to have discovered a process for obtaining 

 silk from half-silk material which leaves nothing to be de- 

 sired as to cheapness or rapidity. He also states that the 

 silk extracted does not suffer in quality nor color, and can be 

 rendered suitable for spinning either alone or mixed with 

 new silk, according to the quality of the material from which 

 it is separated. 13 C^Jidy 1, 1873, 855. 



AMMONIA CHLORIDE FROM BOILING ESTABLISHMENTS. 



Terne, in Dingler's Polytechnic Journal, calls attention to 

 a productive source of ammoniacal salts in the refuse from 

 the slaughter-houses. He refers to the immense establish- 

 ments near Chicago, where from 25,000 to 30,000 cattle are 

 sometimes butchered in a single day. The refuse and the 

 useless flesh are placed in a large iron boiler, and boiled un- 

 der a pressure of three or four atmospheres. The fat rises to 

 the top, and beneath is a liquid which might be considered a 

 solution of glue had not the continued boiling under pressure 

 completely destroyed its binding power. These tank waters, 

 although useless for the manufacture of glues, are suggested 

 by Terne as capable of being profitably utilized, since each 

 quart can be made to furnish from seventy-five to one hun- 

 dred grains of chloride of ammonia. 21 A, November 13, 

 18*73,1170. 



UTILIZING WASTE ORGANIC MATERIAL. 



Within the past few years there has grown up a new in- 

 dustry, based upon the saving of blood and other offal of the 

 slaughter-houses, and the "tankings" (or bottoms of the 



