2l6 PROCEEDINGS OF THE COTTESWOLD CLUB 



manure from the oxide of iron with which it was associated. 

 Experiments showed, however, that the oxide of iron in 

 this so-called basic slag was completely innocuous and all 

 that was necessary to make the phosphoric acid effective 

 as a manure was to reduce the slag to an excessively fine 

 powder. 



The utilization of this waste product as a cheap and 

 unfailing supply of phosphoric acid has been of enormous 

 benefit to Agriculture. Over 400,000 tons of basic slag 

 are yearly available, equal to one-sixth of the total amount 

 of phosphate of hme used in agriculture. 



I will mention just one other curious application of 

 furnace slag; the so-called "slag wool," or silicate cotton. 

 A jet of steam is made to strike upon the stream of 

 molten slag as it flows from the usual spout into the 

 bogies. The steam scatters the slag into shot. As each 

 shot leaves the molten stream it draws out a fine thread, 

 in the same way as if treacle is touched, a fine line can be 

 drawn out. Each fine thread on losing its heat becomes 

 set. The shot drops to the ground, but the thread is 

 sucked into a large tube by an induced current of air 

 caused by the steam jets, and the wool is discharged into 

 a large chamber. It is of a snow-white colour, and 

 attaches itself anywhere, almost as snow will adhere to 

 every tiny twig of a leafless tree. The wool is taken up 

 daily and packed away in bags. It is chiefly used for 

 covering boilers or steam pipes, for which purpose it is 

 peculiarly adapted, being a splendid non-conductor of heat 

 and incombustible. About four tons of this wool are 

 produced per week, and as only J^ cwt. is made from each 

 ton of molten slag operated upon, it will be seen that the 

 process is not a rapid one. 



There is no doubt that very much remains to be done 

 in utilizing both the animal and vegetable products of the 

 sea. Tons and tons of fish are weekly brought into the 

 markets only to be there condemned as unfit for the food 



