1895.] MICROSCOPICAL JOUKJ>rAL. 291 



plate set into tlie wooden standard wliicli is necessary 

 for breaking the tube in the wooden machine. The plate 

 marked (h) is that upon which the striking bar finally 

 rests ; at (i) is noted the attachment for lowering the ap- 

 pliance into the water. The rubber cork (j) is held in 

 position by a swinging clamp. 



In the wooden machine the standard is necessarily 

 somewhat longer, say 2 ft. x 2 in. x 1 in. in measurement. 

 In this appliance the striking bar (b) furnishes the sink- 

 ing weight. It thus should be comparatively heavy. 

 The measurements may be 25 in. x li in. x 5 in. 



In the accompanying plate of sketches, (c) represents 

 a collecting vessel containing a proper amount of water 

 when filled. The depth to which the water fills the ves- 

 sel depends upon the completeness of the vacuum. 



In filling, because of the sudden equilization of air pres- 

 sure and the capillarity of the bore, there will always re- 

 main a certain amount of water in the tube. This is an 

 important matter in the sampling, as, in connection with 

 the air space in the vessel, the possibility of contamina- 

 tion of air and water after the sample is taken is over- 

 come. 



Sketch (B) represents a copper sterilization box for 

 steam sterilizing the sealed tubes on the exterior. The 

 box also serves as a transportation case allowing easy 

 and safe carriage of several collecting vessels. Of course 

 all the test tubes are thoroughly dry sterilized previous 

 to the formation of the vacuum, the rubber corks and 

 glass filling tubes being previously immersed in bichlo- 

 ride solution and alcohol bath. As cultures ought to be 

 made very soon after the taking of the samples, the ca- 

 pillary water in the intake tube serves all the purposes 

 of prevention from external contaminations. If, how- 

 ever, it is wished to keep the samples longer, the intake 

 tube is available for flame-sealing as used in other meth- 

 ods. 



