42 ON THE TRADE IN CORK BARK. 



' Materia Medica' (VoL II,, p. 2220), there is a wood engraving giving a 

 good idea of this insect. 



The statements of Westwood and Quekett, however (' Pharmaceutical 

 Journal,' Vol. XII., p. 482), that Coccus sinensis produces pe-la, render 

 the above assertions very doubtful. Besides, it is stated that the white 

 substance above referred to is washed away by the dew and rain, whereas 

 pe-la is well known to be insoluble in water. I suspect that Flata 

 liinbata exudes a sugary substance — a kind of manna. Helbig (' Miscel- 

 laneorum Ephemerides,' 1693, p. 459, No. 18) mentioned, a kind 

 of Ceylon manna which, perhaps, owes its origin to this insect. At any 

 rate, it would be highly interesting if those who can give information 

 upon this subject would do so. 



ON THE TRADE IN CORK BARK. 



BY THE EDITOR. 



The trade in the bark of the Quercus Suber is one respecting which 

 there is not much recent detail accessible, and yet it is an important 

 article of commerce, our imports reaching in value nearly a quarter of a 

 million sterling.. The demand for and consumption of cork in England 

 has increased, since the year 1848, three hundred per cent, and is still 

 far beyond the actual means of supply. The average imports of cork- 

 bark are about 5,000 tons annually, nearly all of which is used here. 

 Its price varies, according to quality, from 321. to 35Z. per ton, the 

 Spanish cork fetching the highest price. Of ready-made corks the imports 

 have been steadily on the increase, and two-thirds of those imported are 

 used here, the remainder being re-exported. The average price is a little 

 over Is. of foreign per lb. 



Uses. — Cork is light and porous, readily compressible, and wonderfully 

 elastic. These qualities make it superior to all other substances for 

 stoppers for bottles, in the manufacture of which it is principally made 

 use of. It is also employed as buoys to float nets, the construction of 

 life-boats, cork jackets, cork belts, and other life-preservers, cork mat- 

 trasses, the making of waterproof shoes, the lining of hats, models, false 

 limbs, and for various other purposes. When burned, it forms a light- 

 black substance known as Spanish black. 



The cork mattrasses, although intended originally for the army and 

 navy, are valuable, especially for emigrants, and in other ways. The 

 mattrass consists exclusively of minute " clippings" of cork— a material 

 utterly useless for any other purpose, and, until so applied, regarded as 

 worse than " waste ;" for when accumulated, it became absolutely ne- 



