ANTISEPTICS. 79 



disagreeable odour and high price. Three preparations of iodoform 

 are used in surgery, viz. saturated solution in ether, a lo per cent, 

 emulsion in glycerine, and a lo to 20 per cent, ointment in vaseline. 

 The glycerine emulsion is useful in the treatment of abscesses, tuber- 

 culous cavities, and contused wounds, like those caused by carriage 

 poles, etc. Gauze and wadding impregnated with iodoform are 

 largely used as antiseptic dressings. They contain 10, 20, and 30 per 

 cent, of iodoform. Iodoform wadding is used to fill the cavities of 

 wounds, and in dressings applied after operation on the vagina. 



Di = odoform contains 95 per cent, of iodine, whilst iodoform 

 contains only 69 per cent. It is a yellow material, insoluble in water, 

 slightly soluble in alcohol, but very soluble in most hydrocarbons. 

 It keeps well in darkness, is very sensitive to the action of light, and 

 is without odour. It is one of the most active promoters of healing 

 known, though of very slight microbicide power. 



Salol contains about 40 per cent, of carbolic acid, occurs in powder 

 form, like iodoform, and has the advantage of possessing no smell. It 

 is sometimes used for preparing gauze and wadding. 



Cresyl or creolin is very widely used as an antiseptic in veterinary 

 surgery. Being miscible in all proportions with water, alcohol, and 

 glycerine, very slightly toxic, and not attacking either the operator's 

 instruments or hands, it is largely employed. A 3 to 5 per cent, 

 solution is used for disinfecting instruments, infected wounds, and the 

 skin before operation, A i per cent, solution is prepared for disinfect- 

 ing deep wounds, mucous membranes, the uterus, etc. It has, how- 

 ever, the drawback of rendering instruments slippery, and its milky 

 solution prevents their being seen. A 10 per cent, alcoholic solu- 

 tion and a 10 per cent, ointment prepared with vaseline are largely 

 used. 



Formalin consists of a 40 per cent, aqueous solution of formaldehyde. 

 Diluted with four to five hundred parts of water, it becomes a useful 

 disinfectant for the hands, seat of operation, and accidental wounds. 

 Strong solutions are irritant and caustic. Tannoform, glutol and 

 amyloform are compounds of formaldehyde with tannic acid, gelatine, 

 and starch respectively. They form useful dry dressings for open 

 wounds, but are of greatest service when preceded by the application 

 of a liquid disinfectant. 



Chinosol is a yellow, crystalline powder, derived from coal tar. A 

 solution of one part in forty thousand prevents bacterial development, 

 and a grain dissolved in six drachms of water is said to be equal in 

 antiseptic power to a 2.3 per cent, solution of carbolic acid. Solutions 

 for surgical purposes vary in strength between i in 1200 and i in 60. 



