392 WATER OF THE SEA« 



Objen-ations easy to assign a reason why it will not answer to employ soap 

 •^ncctine the* ^^^^^' ocean water. The acids united to the lime and magnesia 

 rroinponcnt being more strongly attracted by the alkali of the soap,, quit 

 mseaTx-^te"^ their Connection with those earths, which fall to the bottom, 

 and the useful while the lighter and deserted oil rises to the top. The ac- 

 that fiuid"^*'^ tivity of the alkali of the soap thus oveTConic by the neutra- 

 lizing acid of the water, can be of little service, and the disen- 

 gaged grease immediately thereafter becomes a reJl im- 

 pediment. 



The basis of all hard soap is soda. The alkaline matter of 

 soft soap is potash. This probably happens because the 

 former is prone to effloresce, the latter to deliquesce in the air. 

 The reason of mingling oil, turpentine and tallow with potash is 

 that this salt is too corrosive to be handled nuked or alone. 

 By its causticity /)o/rt«A destroys the skin and flesh of the 

 ■v^asher, and unless carefully employed, will destroy the goods 

 too. But this is not the case with soda; which in conjunc- 

 tion with carbonic acid may be dissolved in water without ex- 

 ercising any caustic effect upon the arms and fingers of the 

 person who uses it. By virtue of this convenient and excellent, 

 quality, the carbonate of soda can not only be used in a lixi- 

 vial form to cleanse goods, but may be employed to alkalize or 

 soften ocean water and to render it fit for w-ashing with. 



It has been ascertained long ago by Professor Home in his 

 expeiiments on bleaching, that neither sea salt nor any other 

 of the yerftctly neutrah salts composed of an acid and an alkali 

 give any hardness to water ; that the common sorts of sea 

 salt make water hard by means only of the heterogeneous salts 

 they retain from the bittern; and that a/Aa/ies by precipitating 

 the earth of salts with an earthy basis and by neutraliiiing their 

 acids, will soften water. 



Ocean water, it has been shewn, besides o. perfect neutral 

 salt; contains a quantity of saline matter with earthy bases. 

 To these latter, it owes its hardness, or quality to decompound 

 soap. Carbonate of soda decomposes these terrene salts and 

 forms with their acids respectively perfect neutral salts. The 

 water thereupon becomes soft, or in other words, fit for wash- 

 ing goods. 



(To be continued.) 



