APPENDIX 397 



CHEMICAL SOLUTIONS. 



Bichloride of mercury is usually sold in the form of antiseptic tablets. As a 

 disinfectant for the infectious diseases it is usually used in a strength of i-iooo. 

 The solution should be made in a wooden or earthenware vessel. As bichloride 

 forms inert albuminates it should not be used in the disinfection of sputum, faeces 

 or any albuminous excreta. It must be remembered that bichloride is a mordant 

 so that any stains in soiled clothing will remain permanent. For disinfection of 

 clothing the material should be left in i-iooo bichloride for one hour. Dishes 

 for food should never be disinfected in bichloride on account of the danger from 

 poisoning. Floors and walls may be disinfected with i-iooo bichloride applied 

 with a mop. Allow the solution to dry on the floor or walls. 



Formalin. A 5% solution of commercial formalin in water (50 c.c. formalin 

 950 c.c. water) makes a satisfactory disinfectant for soiled clothing. It is also 

 valuable for albuminous material. The disinfectant must act in a strength of 5% 

 so that if one pint of faeces is to be disinfected we should add one pint of a 10% for- 

 malin solution and allow it to act for one hour. 



Carbolic Acid. It is soluble in water to the extent of about 5% and in such 

 strength it is an efficient disinfectant. The solution should be made with hot water. 



In standardizing disinfectants carbolic acid is used as the standard. It how- 

 ever is expensive and there is often difficulty in making up satisfactory solutions. 

 More efficient and more convenient is the Liquor cresolis comp. U. S. P. This may 

 be prepared by mixing up equal parts of cresol and soft soap as noted on page 12. 

 This has a value according to tests made in the Hygenic Laboratory of 3, making 

 it in tests without organic matter three times as efficient as carbolic acid. Under 

 similar conditions lysol had a value of 2.12 creolin 3.25 and trikresol of 2.62. 



Equal parts of a 5% solution of Liq. Cresol. Comp. and the faeces, urine 

 or sputum to be disinfected is satisfactory for disinfection provided the mixture 

 is allowed to stand for one hour. Liq. Cresol. Comp. (5%) is an excellent 

 disinfectant for contaminated bedclothing, etc. It is also most suitable for the 

 disinfection of floors and walls. 



Lime. It must be remembered that air-slaked lime is inert as a disinfectant. 

 For disinfecting faeces freshly prepared milk of lime is excellent. It is made by 

 mixing unslaked lime with four times its volume of water. An equal quantity 

 should be added to the faeces to be disinfected. 



Chlorinated Lime. This can be purchased in air-tight containers and when the 

 package is opened it should give off a powerful odor of chlorine. 



For a working disinfectant solution add i pound to 4 gallons of water. 

 This is satisfactory for mopping floors and for disinfecting faeces, sputum and urine, 

 equal parts of the excreta and disinfecting solution being mixed and allowed to stand 

 for one hour. For disinfection of drinking water one teaspoonful of Jchlorinated 

 lime to i pint of water makes a stock disinfectant. For use one teaspoonful of 

 this stock solution is added to 2 gallons of the drinking water to be disinfected. 

 Let stand at least 1/2 hour. 



INSECTICIDES. 



The following notes are taken chiefly from the U. S. P. H. Service directions. 

 SULPHUR DIOXIDE obtained as described above destroys all animal life. 



