41 
MICROSCOPICAL SECTION. 
15th December, 1862. 
Mr. J. G. Lynde, F.G.S., M. Inst. C. E., in the chair. 
Mr. Alfred Fryer was elected a member of the Section. 
Captain Moodie, of the R.M.S.S. “Canada,” presented 
two soundings taken off Nova Scotia. Captain Thomas 
Millard, of the barque “First of May,” presented speci- 
mens of anchor mud from Montego Bay and the harbours of 
Kingston and Fort Royal, Jamaica; also a sounding from 
the banks of Newfoundland. 
The Chairman stated that he was led to pursue Dr. 
Roberts’s suggestions on the use of magenta dye in examining 
tissues. From experiments made since the last meeting of 
the Section, he finds that the dye has no power to colour 
living tissue, whether animal or vegetable, but that as soon 
as life is extinct the action of the dye commences. He is 
continuing the experiments, which are of a most interesting 
character, and he hopes to lay the result before the next 
meeting of the Section. 
Mr. Leigh considered it probable that so long as vital 
action continued, ordinary endosmosis could not take place. 
Mr. Mosley said that Mr. Hepworth had frequently tried 
magenta for injections, and the results were not satisfactory, 
as the colouring matter diffuses itself through the whole of 
the tissues, giving an appearance of dyed flesh rather than 
that of injected preparations. This appears to confirm the 
preceding observations, and to account for the accumulation 
of colour where the integument is thickest, by means of which 
Dr. Roberts discovered the spot on the red blood discs, as 
announced at the previous meeting. 
Mr. Leigh drew the attention of the Section to the adul- 
teration of size as a cause of mildew in cotton goods. 
Mr. Watson named the investigations made by Mr. 
Thompson about twenty-five years ago, as to the cause of 
mildew in madder purple-printed cottons shipped to hot 
climates. It was attributed to the starch employed in finish- 
ing the goods, which, acted upon by moisture, heat, and 
