SOME EXPERIMENTS WITH DISINFECTANTS 9 



4. One set of cultivations and one of sputunn were placed in the 

 centre of a thick mattress, which had been opened up for 

 the purpose and re-closed. 



Control experiments were at the same time carried out. 



After 3 hours' exposure, the slips of glass were transferred direct into 

 bouillon tubes, without any intermediary process, and incubated at 

 37° C. Within 24 hours, growth occurred in all the control tubes, as 

 also in all the tubes from the 4th set ; while the tubes from the ist, 2nd 

 and 3rd sets remained sterile after 10 days' incubation. The sputum, 

 from exposures Nos. i and 3, were each mixed up with a small quantity 

 of bouillon, and inoculated into guinea-pigs — the sputum from No. 4 

 being rejected owing to the negative results from the cultivations 

 similarly exposed. After an interval often weeks, both guinea-pigs were 

 killed, and in neither case was there the faintest trace of a tubercular 

 lesion. 



Conclusions. — From these experiments, conducted as they were under 

 conditions which severely tested the powers of the apparatus, it will 

 be seen that Lingner's disinfecting apparatus gives trustworthy results in 

 the disinfection of dwelling-rooms, and, as shown by the result of sets 3 

 and 4, the penetrating power of the disengaged vapour, although not 

 sufificient for mattresses or other thick goods, is apparently quite effective 

 for lighter articles of bedding and clothing. 



In the working of the apparatus, I found it advantageous, in order to 

 obtain an immediate and full effect, to begin with very hot water in 

 the boiler. It is also essential to see that all the four jets are working 

 freely. 



2.— The "Alformant" Lamp. 



The Alformant Lamp had also been employed for some years in the 

 Public Health Department of the city, its use being confined to certain 

 cases where its convenience was an inducement. It was, therefore, 

 suggested by Professor Hay that I should also test its efficiency, the 

 more so as its makers ascribed to it a high disinfecting power, and the 

 lamp was widely advertised and used. 



This method of evolving formaldehyde gas consists in the heating of 

 paraform, one of the polymeric forms of formaldehyde, which first melts 

 and then breaks up into the two molecules of formaldhyde gas. The 



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