The Romance of Modern Chemistry

THE VALUE OF THE BY-PRODUCT would have given anything to be rid of. In fact, the utilisation of the hydrochloric acid rapidly became the most profitable part of the manufacture of soda by Leblanc’s method. What was responsible for this sudden transformation, for this striking conversion of waste into wealth ? One of the chief factors was undoubtedly the removal of the duty on paper in 1861, as the reader will agree when the connection between these apparently unconnected events is explained. The removal of the restricting duty gave an immense stimulus to the demand for paper materials. Cotton and linen rags, which had previously served for the manu- facture of paper, were no longer adequate to supply the demand. Other raw materials, straw, wood, and esparto grass, were therefore requisitioned, but these substances had to undergo very drastic treatment before they appeared in the form of paper. Among other things, they required much bleaching, and the source of bleaching materials is hydrochloric acid. Chlorine, prepared from hydrochloric acid, is used for the purpose, either directly or after conversion into bleaching powder. The connec- tion between the paper duty and the fortunes of the soda industry is therefore pretty obvious. The discovery of this valuable outlet for their hydro- chloric acid, and the passing of the Alkali Act in 1863, stimulated the manufacturers to devise improved methods of absorbing the acid; and so efficient is the absorption now that the escaping gases contain less than 0*2 grain of hydrochloric acid per cubic foot. Any one who allows a larger proportion of the acid to escape is liable to a fine. Having seen the good fortune which at length attended the efforts of the alkali trade to get rid of waste product, 276