218 SECRETS OF EARTH AND SEA 



of sea-coal in London, did not become important until 

 the seventeenth century. It came very gradually into 

 use, and we find that Evelyn (the diarist) in 1661 noted 

 the withering and bad condition of rose-bushes and other 

 plants in London gardens, which be attributed to the 

 pestilential action of the smoke given off by the newly 

 introduced " sea-coal " which was increasingly used as 

 fuel in London houses. The sea-coal was not yet largely, 

 if at all, used in the production of iron ; and Evelyn as a 

 forest-owner and lover of trees, has much to say about the 

 necessity for attention to the cultivation of our forests in 

 connection with the iron industry which then flourished 

 in the Weald of Sussex ; charcoal procured by the slow 

 burning or roasting of wood being the fuel used in the 

 smelting furnaces, whilst the ore was the orange-brown 

 wealden sand. It was during the eighteenth century 

 that what we now call simply " coal " came rapidly into 

 use not only for domestic heating, but for furnaces of 

 all kinds employed in industrial enterprise, and, at a 

 later date, for the earlier and later forms of steam-engines. 

 The smoke of the new coal was everywhere regarded as 

 a terrible nuisance, and a source of injury to both animal 

 and vegetable life. The poisonous action of coal-smoke 

 is not due to the finely divided black particles of carbon 

 of which it largely consists, but to the sulphuric acid 

 derived from the small quantities of sulphur present in 

 coal. It is calculated that more than sixteen million tons 

 of coal are annually used in London alone for heating 

 purposes, and that 480,000 tons of black carbon powder 

 are discharged over London by its chimneys every year, 

 together with very nearly the same weight of poisonous 

 sulphuric acid ! 



What, then, is this " sea-coal " or " coal " of our modern 

 life? We all know its black, glistening appearance, and 

 more or less friable character. Its nature and origin are 



