44 



SILOS, ENSILAGE AND SILAGE. 



closes on hinges, while into the sides are inserted two 

 panes of glass facing each other. The top is perforated 

 in the middle by a hole 2 inches in diameter, closed air 

 tight by a sheet of India rubber. This sheet is pierced 

 in the middle by a pin, and through the pin-hole is 

 passed the shank of a long pipette, ending above in a 

 small funnel. A circular tin collar, 2 inches in diam- 

 eter and 1 1-2 inches deep, surrounds the pipette, the 

 space between both being packed with cotton wool 

 moistened with glycerine. Thus the pipette, in moving 

 tip and down, is not only firmly clasped by the India- 



rubber, but it also passes 

 through a stuffing-box of 

 sticky cotton-wool. The 

 width of the aperture 

 closed by the India-rubber 

 secures the free lateral play 

 of the lower end of the 

 k pipette. Into two other 

 smaller apertures in the 

 top of the chamber are in- 

 serted, air-tight, the open 

 ends of two narrow tubes, 

 intended to connect the 

 interior space with the at- 

 mospheric. The tubes are 

 bent several times up and 

 down, so as to intercept 

 and retain the particles car- 



by Such feeble CUr- 



sterilized putresciWe solutions to the air j. Q phancrPQ of fpTYl- 



without producing putrefaction." 



perature might cause to set in between the outer and the 

 inner air. 



" The bottom of the box is pierced with two rows of 

 holes, six in a row, in which are fixed, air-tight, twelve 



* " Floating Matter of tlie Air," p. 132. D. Appleton and Co. 



FIG 3> 



"Tyndall's closed chamber for exposing ried 



