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Bacilli: B. luteus, and B. eta. Yeast: Torula alba. Moulds: Penicillium glaucum and
an undetermined species.
Fresh air.—Five litres, incubated in gelatin at 20° C., yielded 27 colonies, of which
12 were bacteria, 4 yeasts, and 11 moulds.
Five litres, incubated in agar-agar at 37° C., yielded seven colonies, viz., two
bacteria, four streptothrix, and one mould.
The species identified from this 10 litres were as follows :—Micrococci: Sarcina flava,
staphylococcus epidermidis albus, and M. lactis. Bacilli: B. ochraceus, B. helvolus,
B. lactis innocuus, and an undetermined species. Yeasts: Torula alba, torula rosea, and
an undetermined species. Streptothrix: Str. Forsteri. Moulds: Penicillium glaucum
and an allied species. Also an undetermined species of mould.
IV.—On April 4th similiar samples were taken of the air in the tunnels between the Bank
and Lancaster Gate stations. The air was aspirated only while the train was travelling in the
tunnels, not while it was stopping at the stations. The time was 11.45 a.m. The tunnel
temperature was 67° F., and the barometer stood at 30.27 in. The tunnel air contained .082 per
cent, carbon dioxide, and the organic matter was .0010.
Corresponding fresh air samples were then taken under a tree on the grass in Kensingtongardens
at 12.10 p.m. A circle of children who assembled to witness the proceedings were kept
as much as possible to leeward. It was a fine, sunny day, with a moderate W. wind. Temperature
51° F. Barometer 30.2 in. There was 037 per cent, carbon dioxide in the air, and the organic
matter was .0006.
The results were as follows—
Tunnel air.—Five litres, incubated in gelatin at 20° C., yielded 18 colonies, viz.,
10 bacteria and 8 moulds.
Five litres incubated in agar-agar at 37° C. yielded only two colonies, viz., a coccus
and a streptothrix.
The species identified in this 10 litres of air were the following—Micrococci:.
Sarcina lutea, staphylococcus pyogenes albus, staphylococcus cereus flavus and albus,
M. rosettaceus, M. concentricus and an undetermined species. Streptothrix: Str. Forsteri.
Moulds: Penicillium glaucum, aspergillus glaucus, and a mould of undetermined
genus.
Fresh air.—Five litres incubated in gelatin at 20° C. yielded 18 colonies, of which
7 were bacteria and 11 moulds.
Five litres incubated in agar-agar at 37° C. yielded no colonies at all; the plate
remained permanently sterile.
The species identified in the gelatin plate were the following—Micrococci: Staphylococcus
cereus flavus, and micrococcus coronatus. Bacilli: B. vaculatus, B. helvolus,
B. lactis innocuus. Yeast: Torula rosea. Moulds: Penicillium glaucum, a mucor and
at least two species of which I was unable to determine the genus.
V.—Samples were taken in a non-smoking carriage, towards the rear of the train. The
time was 2.45 p.m. The carriage was half empty. The temperature in the carriage was 68° F.,
and the barometer stood at 30.5 in. The carbon dioxide amounted to .111 per cent, and the
organic matter was .0027.
Fresh air samples were then taken in Hyde Park, far out on the grass, and remote from any
people, about 9 inches above the ground. It was a dull, cloudy, cold day, with a light E. wind.
The temperature was 45° F., and the barometer stood at 30.43 in. There was .036 per cent.
carbon dioxide in the air, and the organic matter was .0018.
The results were as follows—
Air of railway carriage.—Five litres incubated in gelatin at 20° C. yielded 27
colonies, made up of 13 bacteria, 1 streptothrix, 1 yeast and 12 moulds.
Five litres incubated in agar-agar at 37° C. yielded 9 colonies, viz., 8 bacteria and
1 streptothrix.
The following species were identified in this 10 litres of air—Micrococci: Sarcina
lutea, sarcina flava, staphylococcus cereus albus and flavus, M. candicanSj M. citreus,
M. lactis, and M. flavus. Bacilli: B. xerosis, B. lactis innocuus, and an undetermined
species. Yeast: Saccharomyces cerevisiie. Streptothrix: Streptothrix Forsteri and
streptothrix chromogenes. Moulds: Penicillium glaucum, aspergillus glaucus, and
aspergillus flavus.
Fresh air.—Five litres incubated in gelatin at 20° C. yielded 17 colonies, of
which 3 were bacteria, 1 a yeast, and 13 moulds.
Five litres incubated in agar-agar at 37° C. yielded only 1 colony, a mould.
The species identified in this 10 litres of air were as follows—Micrococcus: M. lactis.
Bacilli: B. luteus. Yeast: Torula alba. Moulds : Penicillium glaucum, aspergillus
glaucus, numerous colonies of black moulds, of which I could not determine the genus,
and at least three other species.
VI.—On April 11th samples were taken on the down platform of the Bank Station, at
5.10 p.m. It was one of the busiest times of the day; the City men were hurrying home. The
platform was crowded, and loaded trains were going off at short intervals. The samples were
taken at the west end of the platform, where there were few people, but a strong draught was
blowing directly from the crowd to the apparatus. Temperature 67° F., barometer 30.12 in. The
carbon dioxide was .103 per cent., and the organic matter was .0012.
Fresh air samples were taken previously, at 4.50 p.m., on the steps of the Royal Exchange,