13G 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



ring (those used for Cod's patent soda-water bottles serve excellently) 

 complete the requirements. 



To put the parts together, slip the sheaths, oue on to each cud of 

 the glass slide, with their two little screw arms i)rojccting towards 

 each other. Now cut a small piece out of the circumference of the 

 indiaruhber ring, and place it ou the slide between the sheaths, with 

 the opening towards one of the long sides of the slide. Place ou the 

 top of the ring the short piece of glass, aud slide the sheaths towards 

 each other, till the small screws project over its ends. Then, by 

 turning down the screws, the ring is compressed between the two 

 pieces of glass, and a perfectly water-tight cell results. By using rings 

 of diiierent thickness, cells of every convenient depth may be obtained. 



When finished working, the whole can be taken to pieces in an 

 instant and cleaned. If a well-polished piece of glass, free from 

 flaws, be chosen for the upper plate, its thickness will not be found 

 to interfere very materially with the performance of any power 

 below 1/2 in. 



Jung's Compressorium.* — During some histological investigations 

 on Hydra, &c., H. Jung was often obliged, in order to isolate the 



Fio. 23 



Jftyi^y^ZuL 



cells, tissues, &c., to adopt the process of " beating." This, however, 

 he found an exceedingly tiresome process, -especially when it has to be 



* Zeitschr. f. Wiss. Mikr., i. (188i) pp. 248-50 (1 fig.). 



