184 BACTERIOLOGY. 



chamber should be washed out from time to time with 

 hot water, to remove any deposit there may be. 



From Trioxymethylene by Schering's System. This sys- 

 tem consists in heating the solid polymer of formalde- 

 hyde (trioxymethylene) in a lamp specially constructed 

 for the purpose by the Chemische Fabrik auf Actien, 

 in Berlin. The trioxymethylene is used in the form of 

 compressed tablets or pastilles, as being more convenient 

 for use. Each pastille contains the equivalent of 100 

 per cent, of formaldehyde gas, according to the manu- 

 facturers, and weighs 1 gramme. 



The mode of using the apparatus is very simple: 

 The disinfector is placed upon a sheet of iron on the 

 floor of the room to be disinfected. From 100 to 250 

 pastilles can be evaporated at a time in the apparatus. 

 For the production of greater quantities of formalde- 

 hyde vapor several of these outfits may be used 

 together. The lamp is filled with ordinary or wood 

 alcohol, about twice as many cubic centimetres of the 

 alcohol being employed as there are pastilles to be evap- 

 orated. The wicks should project but little above the 

 necks of the burners, or the apparatus may get too hot 

 and ignite the pastilles. The vessel is charged with 

 formalin pastilles and the disinfector placed over the 

 lighted spirit lamp. The lamp is then allowed to burn 

 out in the closed room. One hundred pastilles are con- 

 sidered to be sufficient for the disinfection of 1000 cubic 

 feet of space. Lately, a small steam boiler has been 

 added to the apparatus, for the purpose of furnishing 

 sufficient moisture with the gas. The results obtained 

 by us in superficial disinfection, when from 150 to 200 

 pastilles have been used to each 1000 cubic feet, have 

 been good. The great advantage of the method is in the 



