Three cans of blood serum; same germs, results: No growth. Three cans of same germs on blood serum; result no growth. 4 Staph. Phyog. Aur. Open Temperature 70 degrees. Humidity 86 per cent. (4) 7,500 cubic feet. 1,125 c. c. 234 2 22 234 66 32 22 Wind, S. Rain, Trace. Sunshine 20 per cent. Closed 11:30 A. M. Opened 5:30 P. M. Eight cans of blood serum inoculated with B. Diph., Typhoid, Coli Com. and Staph. Pyog. Aur. Result: Covered with 3-4 thicknesses of bed sheets and pillow cases. Inclined agar tubes with streak cultures. (1) high; Diph. Typhoid Staph. Pyog. Aur. low Controls grew to the top of the agar in the tubes to 1 in. from top. Controls all became turbid, showing growth. • O meaning all bacteria killed. 72 hours. Six dry swabs with infection of B. Diph., Staph., and Strep., incubated in natural bouillon 72 hours; result: no growth. The agar tubes were used for the purpose of determining the penetration of the gas into small and confined places, and if it was present in sufficient quantities to destroy germ life. From the foregoing experiments one can at once see the value of formaldehyde as a disinfectant. Surface disinfection is complete. Where thick mattresses have been soaked with infectious material, it is recommended that they be sprayed with the solution and then folded together and left to lay for some time afterward. Penetration through fabrics occurs to a very great extent, but when too thick nothing short of a vacuum disinfection cylinder, with previous exhaustion of the air and then the admission of formaldehyde gas, would force it to the innermost parts. In the course of hundreds of domestic house disinfections after contagious diseases, it is very seldom that a recurrence of disease is noted. When an entire house is disinfected there is no possibility of a recurrence, as is amply demonstrated by the reports of the Chicago Health Department disinfecting corps. Oftentimes disinfections are requested and performed before a case has really passed through the second or convalescing stage, and if then done disinfection is mere folly. A case should have absolutely recovered before the attempt at general disinfection is undertaken. Disinfection after smallpox has proven that formaldehyde gas is all that can be expected of it as a disinfectant. The cases after which it was performed ranged from the mildest to the severest types, with no recurrence of a single case in any of the premises where the work was done. This method was demonstrated at the meeting of the American Medical Association in June, 1899, since which it has been very ably championed by many experimenters, and the system inaugurated by many health boards and quarantine stations, and also adopted for the disinfection of railway coaches by many of the great lines running into Chicago. A large number of coaches can be disinfected in one day. School boards are also using the method for the disinfection of schools, and in the last year the Board of Education of Chicago has applied the system in infected rooms and school houses, thereby checking an epidemic which seemed to have its origin in those schools. The advantages of this system of disinfection are many- A TEST OF FORMALDEHYDE DISINFECTION. FROM PHOTOGRAPHS. A, C, F, G, H, K-Tubes exposed with open mouths. B, D, E, I, J-Tubes closed cotton plugs. (Health Department Bulletin, May, 1899.) Second-No burden or cumbersome generators have to be carried out, but the sprinkler and supplies can be carried in an ordinary hand satchel, and with an extra supply bottle enough can be taken at the start for three or four disinfections. Third-Nothing is destroyed in the houses disinfected, as usually occurred after the old sulphur fumigation. Fourth-Each room becomes its own source of disinfection. Sixth-It does not require hours of waiting on the part of the operator for the solution to evaporate, as is necessary when generators are used. Entire disinfection is made as nearly perfect as can possibly be done; any person can thoroughly disinfect his own house, and it is the belief of the writer that the question of domestic disinfection has been solved. CHAS. W. BEHм, Bachnologist Chicago Health Department. |