690 KERATIN 



' Sanitas ' or other soothing antiseptic powder. Gently 

 rubbed over slight burns or scalds, soap prevents access 

 of air and relieves irritation. In chronic eczema, soft 

 soap, from its lubricant and alkaline properties, is often 

 useful. For such cases a convenient dressing is made 

 with equal parts soft soap and glycerin, half a part of 

 zinc oxide, and six or eight parts water. For eczema and 

 other itching skin diseases, M'Call Anderson prescribed 

 equal parts of soft soap, oil of cade, and rectified spirit. 

 As a stimulant for bruises and strains, or for producing 

 counter-irritation in sore-throat, six ounces of hard soap, 

 cut into small pieces, are macerated with six fluid ounces 

 of dilute liquor ammonise and one pint each of alcohol 

 (60 per cent.), and linseed oil ; two or three ounces of 

 camphor are sometimes added. Soap and water is much 

 used for clysters. As internal antacids, soaps are less 

 effectual than alkaline carbonates or bicarbonates, but are 

 occasionally administered in poisoning by acids and metallic 

 salts. Soap and water causes emesis in dogs. Soaps are 

 used as excipients for boluses, and as constituents of lini- 

 ments and plasters. 



KERATIN 



A mucilaginous solution which, when dry, is a yellow gum- 

 like substance, insoluble in gastric juice, but soluble 

 in the intestinal juices, and used for coating boluses 

 or pills which are required to pass through the 

 stomach unchanged, and to undergo solution in the 

 intestines. 



Keratin is prepared by digesting horn-turnings with acidi- 

 fied pepsin solution, so long as they yield any soluble 

 matters. The residue is then digested in solution of am- 

 monia or acetic acid, and evaporated. Keratin requires 

 to be redissolved before use. The ammonia solution is 

 generally used, but the acetic acid solution is suitable for 

 those drugs which might be decomposed by ammonia. 

 The medicines, made into bolus in the usual way, are 

 generally thinly covered with cacao butter, and then 



