134 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



carrying everything upon it, moves np ami down, by a rack and 

 pinion, on the upright bar from the base, as shown in the fig. The 



Fig. 10. 



chimney and reservoir are nickel plated and the other ports of 

 brass. 



Live-Cell. — This cell (fig. 20) is of unknown authorship, but is 

 claimed to be convenient when it is desired to keep the water cool in 

 which any living objects are being examined. It dispenses with the 

 alum cell, which is an objectionable adjunct, affecting as it does both 

 illumination and definition. The inner circular cell (open at the top 

 for the reception of the objects) is distinct from the outer rectangular 

 cell, but has six minute holes in its circumference. These allow of 

 a constant interchange between the water in the inner and outer cells, 

 and that in the latter can of course be supplied at any desired tem- 

 perature. Unless the holes are very small, there will of course be a 

 danger of the minuter organisms making their escape into the outer 

 celir 



The cell would seem to be likely to be more useful for lantern 



