1870.] NATURAL HISTORY SOCIETY. 89 



importance, to derive an encouragement for the spread of scien- 

 tific knowledge throughout all classes of the community, Canada, 

 being a country full of mineral wealth, might look to the educa- 

 tion of the industrious classes as one of the great sources of her 

 future wealth and importance ; and although coal was not one of 

 her mineral treasures, yet we should not fail to see that we are as 

 much interested as consumers of its products, as if we were pro- 

 ducers of it as a mineral. The different varieties of coal — anthra- 

 cite, cannel, albertite, &c., — were then described, and the produc- 

 tion of coal-gas illustrated by a large diagram showing the 

 interior of a gas works. The first product of coal, illuminating 

 gas, being illustrated by a photometer, by which the Montreal 

 gas was declared to be equal to 21 sperm candles, which, he 

 believed, was superior to any in Canada, and equal to most of 

 the large towns of the north of England, the " applied science " 

 was to be found in the choice of suitable admixtures of coal to 

 form the best coke as well as the best and purest gas. The use 

 of gas as fuel, by Siemann's Regenerative Furnaces, was next 

 described ; and this mode was recommended as the most economi- 

 cal for any coal containing much gas; by its aid a new process for 

 the production of soda ash was now being worked with much success 

 in Liverpool. In the necessary purification of gas for illuminat- 

 ing purposes, quantities of tar and ammoniacal liquor are pro- 

 duced ; and by the chemical treatment of the tar especially, new 

 and valuable products are obtained. The benzole so largely em- 

 ployed for the solution and manufacture of rubber compounds is 

 derived from this source, as also the asphalt of our pavements, 

 roofing and tarpaulings. In cookery and perfumery we meet with 

 nitro-benzole under the name of almond flavour, from which is 

 derived aniline, the base of that beautiful series of colours well 

 known as the aniline dyes. Important as these are in a com- 

 mercial point of view, they are surpassed in social importance by 

 the production of carbolic acid, which now stands at the head of 

 our disinfecting agents. From this substance is also obtained a 

 yellow dye, picric acid, which is said to possess explosive proper- 

 ties rivalling gun-cotton and nitro-glycerine. Finally, from the 

 ammonia and sulphur recovered from the process, we have valu- 

 able fertilizing agents which, when returned to the soil, complete 

 the great cycle of vegetable existence. From this brief review of 

 the value of applied science to coal, Dr. Edwards urged the 

 importance of the establishment of schools of technical science 



