REPORTS FROM THE SECTIONS. ; 261 
@ preparation of the haustellium (proboscis) of this insect, and also 
a series of drawings of the same magnified about 30 diameters. 
The Crarrman called the attention of the meeting to a box of 
polishing powder, sold under the title “ Oriental Polish,” which on 
examination proved to be a diatomaceous deposit of the purest 
character, fully 90 per cent. being the siliceous loricee of diato- 
ce, 
Mr. Pepiey exhibited the curious wheel-like plates which form . 
the calcareous skeleton of the chirodota, from specimens found in 
Double 2 
Dr. Morris showed sponge spicules and diatoms from Sydney 
water ; and Mr. H. Paterson, a preparation of the fumes of 
mercury. 
_ Mr. W. MacDonnetu exhibited one of Seibert’s 50th inch 
Immersion lenses, and resolved some difficult tests with a Zeiss’ 
25th inch immersion lens, the microscope in this case being one of 
Swift’s upon the improved Hartnach model. 
MONDAY, 10 JUNE, 1878. 
The Rev. George Martin in the Chair. 
The minutes of the previous meeting were read and confirmed. 
Mr. Hirsr exhibited a reduced diagram of a photograph of 
MONDAY, 8 JULY, 1878. 
The Rey. G. Martin in the Chair. 
lefts: B | ‘obliquity of light may be 
_ By this means any degree of obliquity nay 
obtained, the axis upon which it is worked being central with the 
object under examination. To such an extent can this motion be 
carried, that the mirror ma be used asa condenser for the 
