228 
of the inquiry he would communicate on a future occasion. 
Mr. John Graham remarked that much information on the 
effects of small and continued doses of arsenic might probably 
be gained in Manchester, where arsenical preparations were 
used in so many different manufactures. Dr. Roscoe stated 
that he should feel much obliged if the members could give 
him opportunity of examining any case of the action of 
arsenic upon the human body. 
ftllCROSCOFICAL SECTION. 
March 19 th, 1860. 
A communication was read from Mr. John Hepworth, of 
Crofts Bank, accompanying a box of mounted specimens of 
various kinds of cotton and other fibrous materials. 
Mr. Hepworth states that “ the average breadth of the 
cotton cell is about v^th of an inch, except near its attach- 
ment, where it gradually tapers to about —oVoth of an inch. 
“ The ultimate fibre of which the cell wall is composed is 
longitudinal, and inclined in a spiral direction round the tube 
( ? this might arise from position) ; it is rarely seen, and 
never, Mr. Hepworth thinks, e.xcept with polarised light and 
good definition. The cell wall in most specimens appears 
homogeneous.” 
Mr. Dancer presented a bottle of water from his Marine 
Aquarium, containing large Rotifers and other Marine Infu- 
soria. 
Mr. Brittain exhibited a specimen of a new mode of 
mounting large objects in Canada Balsam. 
