PRACTICAL DISIXFECTIOX AND STERILIZATION 



125 



FIG. 65 



formaldehyde is prevented. A further action of the intense heat in the 

 copper tube on the solution is to partially convert the methyl-alcohol 

 contained in commercial formalin into formaldehyde gas by partial 

 oxidation, thereby preventing the formation of methyl and increasing 

 the amount of formaldehyde. 



The apparatus consists of a closed receiver of copper holding about 

 a gallon, a coil of copper pipe attached at one end to the bottom of the 

 receiver, and, like the preceding apparatus and that made by Lentz, 

 at the other, by means of a suitable connection (rubber tube with gutta- 

 percha or metallic mouth-piece), with the room or apartment to be 

 disinfected, and a heating lamp (Swedish lamp or Bunsen burner). In 

 operation the desired quantity of formalin 

 is placed in the receiver and the receiver is 

 closed. The lamp is lighted and the coil 

 brought to a red heat. The valve is then 

 opened and the solution contained in the 

 receiver is allowed to pass down and into Q= 

 the coil in a fine stream. Upon coming in 

 contact with the heated metal the formal- 

 dehyde solution is instantly decomposed, 

 and the liberated gas is further purified as 

 it progresses through the incandescent coil. 

 The apparatus is liable to get out of order, 

 in that the valve is apt to become clogged 

 and so stop the flow of formalin until freed 

 by a wire supplied for the purpose. 



In the new form (Fig. 65) the formalin 

 is first boiled in the large chamber and 

 passes as vapor through the tube connect- 

 ing B and C. In C it is superheated and 

 passes out the tube D into the room. In' 

 this apparatus there is nothing to get out 

 of order, and it operates quickly. Up to 

 the present time this is the most practical 

 apparatus we have met with, when the initial cost, about $25, is not 

 an objection. In all forms of apparatus where formalin is used the large 

 receiving chamber should be washed out from time to time with hot 

 water, to remove any deposit there may be. 



Trioxymethylene by Schering's System. This system consists in heat- 

 ing the solid polymer of formaldehyde (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 com- 

 pressed tablets or pastilles, as being more convenient for use. Each 

 pastille contains the equivalent of 100 per cent, of formaldehyde gas, 

 according to the manufacturers, and weighs 1 gram. 



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. 



Formaldehyde apparatus. 



