! 6 2 >R- MADD OX'S APPARA TUS 



air is produced by placing a lighted lamp under the 

 funnel, as shown in the drawing. 



When the apparatus is to be used vertically, the 

 extra brass tube (Fig. 78) is to be slipped over the 

 end, and the whole is to be supported by one of the 

 retort-holders of the laboratory, or in any convenient 

 way, and beneath the open end of the little funnel is 

 to be placed a lighted oil or spirit lamp, in order that 

 a current of air may be generated. Its position 

 above the surface of the ground may vary from a few 

 to many inches or feet, according to choice. Dr. 

 Maddox thinks about 3 feet the proper height. If it 

 be desired to test the efficacy of various vapours or 

 fluids as disinfectants for the purpose of destroying 

 the living germs, an extra nozzle (Fig. 77) made 

 as a flat box having a small nozzle projecting from 

 the cover, looking towards the thin glass, can be 

 screwed on the ordinary one. "If this narrow box, 

 which should be platinized inside, be packed with 

 fine cotton wool, damped at one part with any article, 

 as creosote, tincture of the muriate of iron, or solution 

 of quinine, or a particle of hypochlorite of lime 

 placed at one part, the particles from the air may be 

 supposed to be entrapped amongst the fibres ; but 

 the cotton-wool should, before use, be soaked in 

 absolute alcohol for half an hour, and squeezed dry 

 between heated plates of glass ; or gun-cotton might 

 be used if thought more free from error. The wool 

 from opposite the nozzle might, in each case, be 



