PUTEEFACTION AND INFECTION. 



79 



extrusion, as regards foreign matter, brought into play 

 by water in crystallizing, the thought occurred to me of 

 examining the liquid derived from the fusion of the 

 most transparent ice. At my request, therefore, my 

 assistant arranged the following apparatus for me; — 



Fio. 3. 



Through the plate of an air-pump (fig. 3) passed air- 

 tight the shank of a large funnel. A small glass bulb, 

 B, furnished with a glass stopcock, was attached to the 

 shank of the funnel below. Prior to being put together 

 all parts of the apparatus had been scrupulously cleansed. 

 5 



