264 ESSENTIALS OF BACTERIOLOGY 



This will produce enough gas for disinfection of 1000 cubic 

 feet. 



Solid formaldehyd in the form of candles is useful for small 

 rooms, and some health boards employ it exclusively. 



Sulphur dioxid, or sulphurous acid gas, is a germicide and 

 insecticide, and is much used in 'disinfecting ships after yellow 

 fever and malaria. It is obtained by burning sulphur in a pan 

 over water, and about 3 pounds to 1000 cubic feet are 

 necessary. 



Copper sulphate, i part to 1,000,000 of water, is effective 

 in destroying algae, and is useful in large reservoirs as a tem- 

 porary disinfectant. 



Alcohol, iodin, chlorin, potassium permanganate, hydrogen 

 dioxid, the salts of silver, lead, and zinc, salicylic acid, boric acid, 

 anilin dyes (methyl-violet and methylene-Uue) , naphthalin, and 

 creosols are a few of the substances in use as antiseptics and 

 germicides in surgery. Their power varies with the strength 

 of the solution and all have limitations. 



In surgical operations more dependence is placed today 

 on securing and maintaining a germ-free or aseptic condition 

 than on the attempt to destroy germ life by chemicals. The 

 irritation of antiseptics in some instances prevents the natural 

 body defenses (phagocytes) from acting, and in abdominal 

 operations, where no pus has been encountered, the blood- 

 serum is sufficient or normal salt solution is alone used. 



Sterilization of Hands, etc. It has been shown by elaborate 

 experiments that the skin, the hair, and clothing harbor many 

 bacteria, some of a pathogenic nature. The surgeon who is 

 anxious to secure good results should carefully attend to his 

 toilet; the use of operating gowns, rubber gloves, operating 

 shoes, face guards is now universal. The toilet of the hands 

 of the surgeon is as important as that of the field of operation, 

 but with the use of rubber gloves the painstaking directions as 

 to the employment of a half-dozen or more cleansing agents 

 and germicides are no longer followed. 



Soap is an efficient germicide, the lye being in most cases 

 powerful enough to prevent the growth of germs. 



