L. TECHNOLOGY. 441 



very fine appearance, the single grains being well formed and 

 plump, but having a grayish tinge from a white powder in 

 the rings of the bodies. Baudimont found that such cochi- 

 neal is adulterated with sulphate of baryta to the amount of 

 twenty per cent. By shaking about fifteen grains of cochi- 

 neal with sixty or seventy of ether, a deposit of baryta soon 

 shows itself. The most remarkable effect of this adulteration, 

 however, is that the product is specifically lighter than the 

 genuine article, in spite of the heavy baryta. The modus 

 operandi explains this seeming paradox. The cochineal is 

 swelled by steaming, and afterwards rolled in precipitated 

 baryta ; it thereby absorbs about eleven per cent, of water, 

 while the genuine contains only from four to six. Baudi- 

 mont ascertained that this manipulation is publicly done by 

 three London establishments, the article being sold under 

 the name of Cochenille plomb'ee or chargee. The consumer is 

 therefore defrauded, since he pays the price of a genuine ar- 

 ticle, and obtains one compounded with water and baryta. 

 13 (7, 1871, v., 330. 



SIZE FOR COTTON YARN. 



The following size is recommended by a German chemist 

 as especially adapted for fine cotton chain yarns : One ounce 

 of gum arabic is dissolved in three ounces of water by boil- 

 ing, and two ounces of wax are added. This mixture is then 

 well stirred, and, when cold, appears as a pale yellow paste, 

 which is to be added, while hot, to a dressing made of five 

 pounds of best wheat flour. This size makes the chain dura- 

 ble and smooth, and never cracks, even during the greatest 

 heat of summer time. 5 (7, xix., 152. 



A CHEAP AND LUSTROUS SIZING. 



Mr. C. Puscher, of Nuremburg, recommends a special kind 

 of sizing for finishing linen and cotton fabrics, and for other 

 purposes, not only on account of its.superior quality, but for 

 its economy, as he thinks one third the ordinary expense can 

 be saved. It is prepared as follows : Into six pounds of cold 

 water one pound of the best quality of wheat flour is stirred, 

 and when well mixed one ounce of aqua ammonia is added, 

 while the mass is at the same time kept in motion. The flour 

 swells considerably, and assumes a pale yellow color. Five 



T2 



