to QUATERCENTENARY STUDIES IN PATHOLOGY 



lamp is cheap and light, and of very simple construction, consisting of a 

 receptacle or basin for holding the paraform, or, as they are commonly 

 called, the "formaline tablets," with a small methylated spirit lamp 

 beneath. The disadvantages of the method are that the gas is given off 

 without moisture, and tends to polymerize readily, especially on cool, dry 

 days. The gas is also given off rather slowly, and with little force, so 

 that it permeates slowly to all the crevices and corners of a room. The 

 room to be disinfected must have all cracks and crevices carefully 

 sealed up. 



Dr. Kenwood, in a paper read at Leeds, in 1897, stated that he had 

 succeeded, by means of the lamp, in sterilizing swabs infected with B. 

 diphtheriae, using 21 tabloids in a room of 2,004 cubic feet, with a four 

 hours' exposure. More recent experiments, under varied conditions, 

 seem to have given very mixed results, and Kenwood now advocates 

 using 25 tablets per 1,000 cubic feet, if disinfection is to be ensured. 

 Allan, in 1898, in a series of comparative experiments with sulphur 

 dioxide and formaldehyde, conducted in two ordinary dwelling-rooms, 

 used 10 tablets for each 1,000 cubic feet, as recommended by the makers, 

 and got satisfactory results. He found (i) that it was not so much a 

 question of time as of initial volume of gas liberated, and suggested 

 using a large number of lamps rather than a large number of tablets in 

 one lamp ; (2) that the gas had no great power of penetration ; and (3) 

 that the generating apparatus should be as near to the floor as possible. 



The following experiment was conducted with the view of comparing 

 the Alformant lamp method with the Lingner method. In order that 

 the comparison might be as fair as possible, the house used in experi- 

 ment I was employed, and the same conditions were adhered to, viz., 

 merely stopping up the chimney. In order that the initial volume of the 

 gas should be as large as possible, I used two lamps, with 30 tablets in 

 each, giving approximately 24 tablets per 1,000 cubic feet. The relative 

 humidity of the air before starting was 86 per cent. ; the inside 

 temperature was 56° F. The organisms used in this experiment were (i) 

 actively sporing Bacillus anthracis, (2) 24 hours' culture on agar of 

 Staphylococcus pyogenes aureus, (3) Bacillus typhosus, and (4) Bacillus 

 coli communis. 



Technique. — Small pieces of glass, i in. long by J in. broad, were 

 sterilized in the hot air chamber. Emulsions of the different cultures 



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