50 PROCEEDINGS OF SOCIETIES. 
should show no colouring ring; should it do so, the whole must 
be rejected. Supposing the precipitation to be complete or very 
nearly so, shake vigorously for half an hour, and allow to stand 
till quite cold; the shaking must then be reuewed, and the bottle 
filled up with cold water. 
After allowing the precipitate to settle for a day, draw off the 
clear supernatant fluid with a syphon. Repeat the washing till 
the clear fluid gives little or no precipitate with chloride of barium. 
So much water must be left with the fluid that at last it must 
measure 40 fluid oz. For the injection fluid take 240z. of the 
above coloured fluid, and 3 oz. of good gelatine, allow these to 
remain together all night, then dissolve by the heat of a water 
bath, after which it should be strained through fine muslin. On 
injecting, the ordinary precautions for a gelatine injection are 
alone necessary. 
Professor Williamson stated that, owing to the unexpected 
absence of his esteemed friend, Mr. Sidebotham, he had been 
suddenly called upon to give the members of the society an 
address at the opening of the session. With so short a warning 
it was not an easy task; still, as a few stimulating words might 
lead to extra exertion, he would make a few remarks on the 
present position of the microscopic observers. Their numbers in 
Manchester were necessarily small compared with London. Per- 
haps there were not twenty microscopists in this city really at 
work; few were able to devote the time to the energetic and 
laborious efforts which original investigation required, and of 
these fewer had the talent or even the ambition to undertake what 
requires weeks, months, nay, often years of arduous toil. The 
hindrances are increased by the fact, that there is rarely a definite 
end sufficiently certain of attainment in the way of a new dis- 
covery, calculated to repay the expenditure of labour. 
Hence, in a small society like ours, we cannot expect great or 
brilliant results. But further, the present is not an epoch like 
that when Ehrenberg revolutionised an entire branch of science, 
or when Grew laid the foundations of vegetable physiology, and 
Malpighi that of the animal kingdom. ‘These men revealed en- 
tirely new fields of inquiry. But though no such new worlds of 
histology are opened out to us, there are such a multitude of 
secondary details requiring elucidation, that we cannot take up a 
plant or insect without stumbling upon a multiplicity of problems 
awaiting investigation. One shrewd observer, when eating his 
orange, discovers upon them some brown scales. He follows up 
the inquiry they suggest, and the result is an elaborate paper on 
the coccus of the orange. 
Even where members are not prepared for original researches 
they still may do excellent service by examining the ground gone 
over by other men, whose views require corroboration before their 
somewhat startling conclusions can be unhesiiatingly received. 
He would refer to such inquiries as Dr. Hicks’s on the conversion 
of the protoplasm of the Volvox into free-moying Amebe, and to 
ee a 
