156 CHAPTER 17. 



308. Demulcents. 



Demulcents have a purely local action. When taken internally they 

 form a coating, so far as they reach in an undiluted form, to the mucous 

 linings, and protect them from irritation. In sore throat, for instance, 

 in ourselves, we readily recognise the benefits of demulcents in protecting 

 the mucous lining of the throat from the irritating effects of cold raw 

 air. They are also serviceable in preventing acrid secretions from coming 

 in contact with delicate and irritable surfaces. Hence they are given in 

 cases of diarrhoea. 



Demulcents are made either of linseed boiled to a jelly and mixed with 

 the food, or by pouring boiling water on the seeds in the proportion of 

 one pint of water to an ounce of seed. The latter must be left to stand 

 till cold, when a thick solution will be obtained. 



Another and perhaps better preparation is made by throwing the lin- 

 seed by a handful at a time into boiling water. Each handful then gets 

 well scalded at once. 



309. External dressings. 



External dressings in cases of wounds are useful in protecting the parts 

 from the irritating effects of the air, of flies, &c. ; and secondly in lower- 

 ing the temperature of superficial inflamed parts. 



For the first-named purpose cotton wool or strips of cotton dipped 

 in collodion, or a rag wetted with Goulard lotion or cold water answer 

 well. Carbolic acid made into a paste with chalk, or collodion applied 

 over the part with a camel's hair brush will often be found useful in 

 forming an artificial eschar over a sore. For the second-named purpose 

 a rag kept wet with water or with a refrigerating lotion may be used. 



To prevent attacks of flies, which in, hot weather are especially apt to 

 be troublesome, the parts may be lightly smeared with spirits of tar, 

 naphtha, petroleum, or diluted carbolic acid. In hot climates much of 

 the success in treatment of wounds and sores depends on keeping off 

 flies. Maggots in a wound will be best got rid of by dressings of equal 

 parts of spirits of turpentine and oil. 



Under the head of external dressings are also included the applications 

 used for mange, ringworm, lice, &c. These will be given under the heads 

 of the diseases to which they respectively refer. 



Digestive dressings, for which some recipes will be found in the next 

 paragraph, are also much employed ; but the benefit derived from their 

 use is questionable. 



310. Digestive liniments. 



Turpentine Liniment is much employed as a rubefacient, and as a 

 digestive on abraded surfaces. It is usually made as under. 

 Oil of turpentime . 1 part. 

 QUve oil . , .4 parts. 



