Sffi WILLIAM SIEMENS, F.K.S. 365 



economically than fuel, because we can adjust the amount of air 

 necessary for its combustion with the greatest accuracy. We can 

 burn cuke with much more heat than raw coal because it does 

 not fly off of its own accord into smoke. Therefore by simply 

 st'i>uratii)g these two constituents of coal we take each of them at 

 a much greater advantage to ourselves. 



But another element presents itself which is of the greatest 

 importance, and that is the element of the secondary products 

 which modern science has brought to the fore. Not very many 

 years ago perhaps 20 coal tar was almost valueless ; gas 

 companies sold it for one halfpenny a gallon. In like manner 

 ammonia-water was allowed to run waste and to poison the fish 

 in our brooks. I have lately had occasion to estimate the value of 

 these products that were utterly wasted 20 years ago, and I find 

 to my astonishment that they exceed in value all the coal that is 

 used at those works the gas works where they are produced. 

 The total amount of coal used at our gas works is something like 

 nine million tons, which may be valued at four and a half million 

 pounds. The waste products, including the coke, have been 

 valued at seven million pounds sterling in England, showing that 

 their value exceeds by two and a half millions the total value 

 of all the coal consumed in producing the gas. Not only have we, 

 by the use of coal tar, turned to account this enormous amount of 

 waste products, but we have enriched our aits and manufactures 

 by those beautiful colours which now give the art of dyeing a new 

 and enormous development. (Applause.) The ammonia liquor 

 has a national value, because it is the only source from which 

 ammonia can be obtained that can be depended upon for agricul- 

 tural purposes, and there is an unlimited demand for it in that 

 direction. If we can only make up our minds to use fuel in the 

 refined forms of gas and coke, we should have the command of 

 much larger value than they themselves come to in the secondary 

 products. Therefore the point which science and the arts should 

 be directed to chiefly is the prevention of waste. In doing so we 

 should vastly increase not only our national resources but our 

 individual well being. We have an old proverb which says, 

 "Waste not, want not." We have had it in our mouths for 

 hundreds of years, but we are only now beginning to realise it 

 scientifically. (Loud and prolonged applause.) 



