SCIENTIFIC MISCELLANY. 443- 



purified. At least Pliny mentions this; and it also would appear that 

 Charles I had tablecloths made of it, which he also was accustomed to 

 throw into the fire for the same purpose. More recently stockings and 

 handkerchief were made in Elba of asbestos, as gifts to Napoleon I, while 

 living there an exile. From time immemorial the peasantry, where it is 

 found, in various countries, have turned it to economical use as an incom- 

 bustible lampwick, for which purpose its power of capillary attraction ad- 

 mirably qualifies it. 



Common asbestos, more or less fibrous, but of a powdery, brittle quality, 

 is abundant in most countries, and begins to find its way into some of the 

 industrial arts, but largely mixed with other materials. The strong, long, 

 fibrous sorts, varying in color from pure white to dark brown, thus far are 

 only found in sufficient quantity for commerce in the Italian Alps, at eleva- 

 tions of several thousand feet, and often, for much of the year, buried in the 

 snow. They occur in serpentine rocks in irregular veins, usually very nar. 

 row, requiring much heavy labor and blasting to open. Sometimes, but 

 very rarely, masses are found in one lump weighing several hundredweight. 

 More frequently the veins prove very superficial, and give out almost at 

 once. Then, again ; they can be steadily worked for years, as they extend 

 or penetrate into the mountains. Although some of these have been yield- 

 hig as much fibre as there was a demand for since they were first opened in 

 1871-72, recently the increased call has led to the discovery of new produc- 

 tive veins of the very best quality, whicli will increase the outcome from a 

 few scores of tons per annum to several hundreds. But the price, hereto- 

 fore varying from £50 to £100 a ton, according to the quality and condi- 

 tion of the fibre, threatens to grow firmer, owing to the new uses now 

 springing up for it, mostl}^ based on patents, whilst Italian capitalists them- 

 selves begin to see the importance of a mineral, of which Italy has as yet a 

 virtual monopoly, and are preparing to manufacture it on the spot where 

 it is found in those goods which already find a steady and increasing de- 

 mand. 



These are chiefly, steam-packing in the rope or loose form for piston and 

 pump rods, and stuffing boxes, and mill-boards for steam-joints, gaskets, 

 man-hole plates, and a species of felting to cover boilers and steam-j)ipes. 

 The ability of asbestos to resist an elevated temperature, moisture, friction 

 and flame itself, joined to its lubricating quality, specially recommends it 

 for the above purpose. The chief objection with the manufacturer is that, 

 when properly prepared and applied, it lasts too long. As covering for 

 boilers and pipes, it saves 25 per cent, or more of the waste heat ; and in 

 domestic uses in cellars, to prevent loss of heat by radiation, it is found to* 

 reduce the temperature of the cellar 15°, while raising that of the house- 

 abave 10° ; i. e., it saves the furnace or steam heat, and sends it where it is 

 most wanted. 



Asbestos lining or sheathing paper, especially for wooden houses, for ceil- 

 ings, floors and partitions, to prevent the spreading of flames and make 



