ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



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through the band B, driven by a water-motor, A, to the wheel C. The 

 rotary movement is converted into a swinging one through the rods 

 E, G, J. To J can be fixed, by means of a clamp, any vessel, such as an 

 Erlenmeyer's flask ; this swings in a water bath, L ; the level of the 

 water is so arranged that about one third of the vessel is immersed. 

 The water is kept at the desired temperature by means of a gas thermo- 





Fig. 123. 



regulator. The number of oscillations is given by the turns of the 

 motor, and these can be regulated within certain limits. 



Different kinds of oscillation may be imparted by setting the rod E 

 in different holes at I), and these movements may be further graduated 

 through the intermediary of the block F, to which the rods E, G, J 

 are connected directly, and with the wheel C and the piece H indirectly. 



