108 
red and blue being the predominant colours. A few granules of 
starch, seen by the aid of the polariscope, and several long ellip- 
tical bodies, similar to the pollen of the lily, were noticed. After 
this dust from the atmosphere had been kept quiet for three or 
four days, animalculse made their appearance in considerable 
numbers, the monads being the most numerous. Amongst these 
were noticed some comparatively large specimens of Paramecium 
amelia , in company with some very active Rotifers ; but after a 
few days the animal life rapidly decreased, and in twelve days no 
animalculse could be detected. 
Hairs of animals . — Very few of these were noticed, with the 
exception of wool ; of this both white and coloured specimens 
were mixed up along with the filaments of cotton. 
After each examination as much of the drop of water as could 
be collected by the pipette w r as returned to the bottle, in order 
to ascertain if any new development of animal or vegetable life 
would take place, and the stopper of the bottle was replaced as 
quickly as possible to prevent the admission of the particles from 
the air in the room ; and I am tolerably certain that the objects 
named in this paper are those which the bottle contained when 
Dr. Smith brought it to me. 
The particles floating in the atmosphere will differ in character 
according to the season of the year, the direction of the wind, and 
the locality in which they are collected, and, as might be expected, 
are much less in quantity after rain. 
The small amount of fluid now remaining in the bottle emits 
the peculiar odour of mildew, and at present the fungoid matter 
appears inactive. 
For the purpose of obtaining a rough approximation of the 
number of spores or germs of organic matter contained in the 
fluid received from Dr. Smith, I measured a quantity by the 
pipette, and found it contained 150 drops of the size used in each 
examination. Now, I have previously stated that in each drop 
there were about 250,000 of these spores, and as there were 150 
drops, the sum total reaches the startling number of 371 millions, 
and these, exclusive of other substances, were collected from 2 495 
litres of the air of this city 1 — a quantity which wmuld be respired 
in about ten hours by a man of ordinary size when actively 
employed. I have to add that there w r as a marked absence of 
particles of carbon amongst the collected matter. 
MICROSCOPICAL ANU NATURAL HISTORY SECTION. 
February 2477«, 1868. J. B. Dancer, F.R.A.S., President of 
the Section, in the chair. 
Mr. Sidebotham sent two beautifully finished water-colour 
drawings, accompanied by the following note : 
“ I send you a couple of drawings of the dry-rot fungus 
Merulius lachrymans, remarkably fine. Mr. Lynde, our treasurer, 
1 Behind Dr. It. Angus Smith’s laboratory. 
