SOAP 175 



The kind of soap produced depends upon the materials used 

 and the care with which the soap is made. Good results can 

 be obtained only from good material, and then only if care is 

 exercised. When the hydroxide is completely " saponified " 

 there is no free alkali and the soap is suitable for toilet pur- 

 poses. 



Cheap soaps are usually the most expensive, as the free 

 alkali which they contain will destroy fabrics washed with 

 them. 



References : 



1. 1702:200-201. Saponiflcation. 



2. 1703:340-341. Soap. 



3. 1710 : 96-103. Soap and Soap Powders, 

 a. 1701:410-411. Saponification. 



6. 1704 : 226-230. The Manufacture of Soap. 



c. 1705 : 156. Saponification. 



d. 1706:422-423. Soap. 



e. 1707 : 465-467. Soap and its Action on Hard Water. 



f. 1708 : 206-207. Soaps and their Action. 



g. 1709 : 387-389. Soap and Soap Making. 

 h. 1711 : 299-300. Oils and Fats Soap. 

 i. 1712 : 300-302. Soaps and their Action. 

 j. 1713 : 19. Soaps, Medicaments, etc. 



Experiment 67. To Make Soap. 



Apparatus: Ring stand, burner, iron dish. 



Materials : Lard, sodium hydrate, 15 per cent solution, salt. 



a. Take about 60 c.c. of the sodium hydrate solution, in the 

 iron dish, and add about 25 g. of lard. Boil slowly for ten 

 minutes, and then add, gradually, about 15 g. of salt. Con- 

 tinue to boil for a few minutes. Allow the whole to cool, and 

 remove the soap, which will be on top of the mass. Let the 

 cake dry for a few days, and then test its ability to produce 

 suds. 



