250 A HISTORY OF THE BOD A MANUFACTURE. 



This manufacture was carried out by Mr. Tennaut's then existing 

 firm, and subsequently by bimself and sons, to an extent which has 

 surpassed that of all other manufacturers engaged in the same business. 



I have already referred to the obstruction to the establishment of the 

 soda manufacture, occasioned by the excise duty on salt. In proof of 

 this I may notice the regulations which at that time prevented the 

 use of bleacher's residua, containing lai-ge quantities of sulphate of soda, 

 for any purpose whatever ; and, consequently, these were then rejec- 

 ted as useless, although now the same material forms the basis of a most 

 important business. As this affords a very striking example, amongst 

 many others, that manufactures, as well as commerce, must be free 

 from fiscal restrictions, if they are to be carried on for the benefit of the 

 many, as contradistinguished from that of the few, I may give some par- 

 ticulars of the manner in which this obstruction operated. 



At the period of the French Revolution, the duty on salt in this 

 country was 10Z. per ton. This was subsequently raised, as a war tax, 

 to 30Z. per ton, or thirty times the value of the salt ; and this rate was 

 continued during the whole period of the war, and until 1823, when the 

 duty was repealed. 



In 1798 an act was passed to allow a drawback of the duty paid on 

 salt used and consumed in making oxy-muriatic acid. This boon was 

 confined to those who used the chlorine produced for bleaching pur- 

 poses, and did not extend to the manufacturers of chloride of lime for 

 sale. It also required that the residua, containing sulphate of soda, 

 should be thrown away, thus effectually preventing its application to 

 the manufacture of soda. These regulations continued until 1814, when 

 the law was altered, and the manufacturers of chloride of lime were 

 allowed a drawback of the salt duty, and the restriction as to the use of 

 the residua was removed. About this time Mr. Tennant's patent for 

 bleaching powder having expired, other parties began to manufacture 

 this article, and attention was directed to the utilisation of the mixed 

 sulphate of soda and sulphate of manganese resulting from this manufac- 

 ture ; and some quantity of carbonate of soda, in the state of crystals, 

 was gradually introduced into the market, the value at that time being 

 about 301. per ton. The process usually employed consisted in drying 

 down the solution of mixed salts, roasting the product, mixed with 

 small coal, so as to decompose the sulphate of maganese, then dissolving 

 out the sulphate of soda, drying down the solution, and fluxing the sul- 

 phate of soda with small coal, adding some iron scales, or scrap iron, 

 near the end of the fluxing. The product contained some quantity 

 of carbonate of soda with sulphide of sodium. It was lixiviated, and car- 

 bonate of soda obtained from it by crystallisation. 



During this period, the late Mr. W. Losh was making crystals of 

 soda by Le Blanc's process, and this gentleman may be considered as the 

 father of the soda trade in this country, although not the first to intro- 

 duce the manufacture of soda-ash, on the large scale, by the special 



