XI 



to be easily applied to the reservoir of fluid, is placed 

 upon the central tube, the unattached end and the out- 

 flow tube of the stopcock being wrapped in paper; cot- 

 ton wool corks are placed in the neck of the pipette- 

 bulbs; the overflow tubes from the pipettes are connected 

 by india rubber tubes with the branches (m m 1 ) of the 

 tube in the Erlenmeyer flask (E) and the bent tube (n) 

 in this, is corked with cotton wool. 



By unscrewing the clamp attaching the pipettes to 

 the stand, and unhooking the pedal rods from the beam 

 of the stopcock, the measuring apparatus thus arranged 

 with the Erlenmeyer flask, can be placed in the auto- 

 clave. 



After sterilisation the apparatus is again fixed to the 

 stand, the pedals hooked on and the rubber lube atlached 

 to the reservoir of fluid. 



By the pedal action it will be noticed that as one 

 pipette fills, the other is emptied, though it is so arrang- 

 ed that the tilling process shall not be completed un- 

 til after the contents of the other pipette have been en- 

 tirely discharged, and, that when the beam of the stopcock 

 is in a horizontal position there can be neither inflow 

 nor outflow of fluid in any direction. 



Further comment on the use of the apparatus for non- 

 sterile fluids is unnecessary. 



1) The apparatus can be obtained From : Cornelius Knudsen's mckaniskc Etablisse- 

 niciil, Copenhagen. 



