XI 



The measuring apparatus is attached by a support 

 (g) and moveable clamp to the iron stand (h). This ar- 

 rangement makes it possible to alter the distance between 

 the outflow tube of the stopcock and the white enamel- 

 led metal plate (i). The latter forms the table of the 

 apparatus and is supported by a metal bar fixed to the 

 stand (h). 



The stand can be fastened to any table by means of 

 the two screw clamps (k) and the rigidity of the whole 

 is ensured by its passing through the enamelled plate (i) to 

 the floor. 



To allow for the apparatus being fixed to tables of 

 different height, the lower portion of the stand and the 

 brass rods from the pedals to the stopcock are so made 

 that they can be shortened or lengthened accordingly. 



The form of pipette proposed by Kern 1 ) might be pre- 

 ferred by some to that mentioned above. Kern's pipette 

 (provided it is carefully made) has this advantage, that 

 there is no overflow or possible waste of fluid, but on the 

 other hand the quantity of fluid delivered is not always 

 the same, air bubbles of different size frequently collect 

 under the float closing the pipette, and if a viscid fluid 

 (serum, blood etc.) is used, the float will very often ad- 

 here to the side of the pipette and prevent this being 

 emptied. 



For these reasons, the above named pipette has been 

 designed; owing to the small bore of the upper portion, 

 the waste of fluid will be practically nil, and the form- 

 ation of air bubbles prevented by the sharp angle bend. 



If the apparatus is to be used for sterile fluid, it is 

 arranged for sterilisation in the following way: an India 

 rubber tube of required length and of such a width as 



!) Kern, F. ,,Kine automatische Messpipette fur keimfreie Fliissigkeiten" Centralblatt 

 fi'ir Bakteriol u. Parasitk. 1899. Bd XXV. p. 75. 



