324 Scientific Intelligence. 
microscope, designed and used with much success by Mr. D.S 
Holman is constructed to retain the greatest quantity of mate- 
rial under the smallest cover glass, and is designed to be used with 
the highest powers of the microscope for studying the Bacteria, 
Vibriones nad other very low forms of life. : 
e slide consists, as will be seen from the cuts, of a central 
polished cavity, about which is a similar polished bevel ; and from 
the bevel outward extends a 
small cut, the object of which 
is to afford an abundance of bs 
wou come so great, from 
the evaporation of the liquid 
within, as to cause the destruc- 
The bevel is usually } in. in j 
diameter (the cut is } of natural size); the small canal is cut 
through the inner edge of the bevel or annular space, outward, 
for the purpose named above. : 
It is found upon enclosing the animaleule, &c., that they will 
We have repeatedly had the opportunity of witnessing the use 
of this slide, and are convinced that nothing of the kind has yet 
IIL Astronomy. 
1. Extract from the Address of Mr. De La Rur before the rere! 
matical and Physical Section of the British Association of — 
he was President.-Passing to the subject of comets, Mr. De. 
Rue gave an explanation of Prof. Zéllner’s eS theory which, 
e 
