ACTIONS AND USES 687 



giving off irritating vapours of acrolein. Cautiously added 

 to a mixture of equal measures of nitric and sulphuric acids 

 it produces nitro-glycerin C 3 H 5 (N0 3 ) 3 . 



ACTIONS AND USES. Glycerin undiluted irritates the 

 mucous membranes, and even the skin by abstracting 

 water. Hence its laxative effect, whether when swallowed 

 or used as an enema. Dogs are purged by 1 J ounces. Large 

 doses are toxic in animals, causing restlessness, quickened 

 pulse, and respiration, and later tremors and convulsions, 

 ending in coma and death by paralysis of respiration. 

 They break down the red globules and cause haemoglobinuria. 

 especially if injected subcutaneously. Externally, it is 

 antiseptic, and destroys fleas and other skin parasites. 

 Mixed with water, starch, or other bland materials, it is 

 demulcent and emollient. It is the basis of the emollient, 

 antiseptic, and astringent group of glycerina. It is a 

 solvent for fixed alkalies, for alkaloids and their salts, 

 vegetable acids, iodine, bromine, salicin, etc., a frequent 

 constituent of ointments and lotions, and a convenient men- 

 struum for the administration of nauseous medicines. 



It is absorbed fairly rapidly from the intestine and is 

 oxidised in the tissues, but is of little value as a nutrient. 

 Small doses are eliminated by the kidneys, larger by the 

 bowels, producing slight laxative effects, increased by com- 

 bination with castor oil. As a laxative enema it is not more 

 effectual than oil, or soap and water ; indeed, Friedberger 

 states that it has no effect on dogs. Given shortly before 

 meals it has been prescribed to check undue gastric fermen- 

 tation, acidity, and flatulence, both in calves and dogs. 

 It neither evaporates, nor becomes rancid, and is readily 

 miscible with water, spirit, oils, and other drugs, forming 

 with them emollient, antiseptic, or astringent dressings, used 

 to soften, supple, or soothe dry, rough, scurfy, or irritated 

 skin surfaces. It is the basis of many applications for 

 blisters and burns, for cracked heels, and various forms 

 and stages of eczema. Doses, horses and cattle, j. to 

 gij. ; dogs, 3ss. to 3j. 



Glycerin of starch is made by stirring and heating gently 

 one of starch, one and a half of water, and six and a half of 

 glycerin, and is used for aphthous and other eruptions about 



