74 IMPURITY AN» MANUFACTURE 0» 801>A. 



in solution in the mother waters, that have furnished carbon* 

 ate of soda. When the barilla is employed for making soap, 

 the same loss is experienced. The soapboiler's lie contains 

 sulphuretsand hidrosulphurets,which diminish its causticity, 

 as they have a weaker affinity for lime than for soda. The 

 consumption of this alkaline substance in pharmacy, and 

 more especially in soap-making, is sufficiently extensive, to 

 turn the attention of chemists and manufacturers to an im- 

 provement in preparing this alkali ; which i& also much 

 employed in dyeing cotton, and in the washhouse. In the 

 latter, the sulphurets and hidrosulphurets in barilla not only 

 render it so much the dearer, but are injurious to the white- 

 Bess of the linen and cotton*. 

 Farther incon- These are not the only inconveniences arising from the 

 maiencas. high degree of heat, to which the soda is exposed in manu- 

 facturing it. A still greater is, that a part of the alkali enters 

 into combination with the earthy substance contained in the 

 ashes, and forms a kindof frit, indecomposable by the action 

 either of water or of acids ; and the quantity of alkali wasted 

 in forming this semivitrified substance is greater than that 

 taken up in the formation of the sulphurets and hidrosul- 

 fJ^stkocTof pkurets. Here no doubt is a great loss of alkali, occasioned 

 ^voidikig ilifisa. ^jy ^^g semivitrification of the ashes of the plants that furn- 

 ish soda ; and which would be avoided by adopting the mode 

 tised in preparing potash ; lixiviating the ashes, evaporating 

 the lixivium to dryness, and selling the alkaline salt in this 

 state of preparation. The consumer would find so much 



Semjos acci* *Tlie siilpbureta contained in unprepared soda frequently occasion 

 <teM in a soap serious accidents in soap, manufactories. In these, where it is custom- 

 fartoiy. ary to keep cawstic he in large covered stone vats, the sulphurets de- 

 compose the water. The hidrogen not absorbed by the hidrognrettcd 

 sulphurets thus fonned occupies the empty part of the vat. Wheu 

 the workman takes off the cover, to dip out the lie, and holds in hi* 

 hand a lamp to hght the inside of the vat, the hidrogen takes fire, and 

 endangers the butldlug. lu a visit I just paid to Marseilles I saw one 

 of these manufactories, that had been destroyed by a violent cxplosiqn 

 of this kind. The hidrogen being mixed with atmospheric air such 

 an explosion took place, that the house was near being thrown dowm 

 The owncv, supposing the manufacturer had maliciously attempted to 

 destroy hishouse, summoned hira before the magistrate ; and the cause 

 is still pending before the first tribunal of the department. 



the 



