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just inside the railings. A small crowd of people collected around, and had to be moved on by the
police. There was a light shifting N. wind. It had been raining, and was still just spitting
with rain, and was warmer after a cold morning. The temperature was 55° F., and the barometer
was 30.05 in. The organic matter was .0023.
The results were as follows—
Air on station platform—Five litres incubated in gelatin at 20° C. yielded 41
colonies made up of 30 bacteria, 7 streptothrix, one yeast, and 3 moulds.
Five litres incubated in agar-agar at 37° C. yielded 16 colonies, viz., 14 bacterial and
2 streptothrix colonies.
The organisms identified from this 10 litres of air were as follows—Micrococci: Sarcina
lutea, sarcina flava, staphylococcus cereus albus and flavus, M. candicans, M. aurantiacus,
M. lactis and M. flavus. Bacilli: B. helvolus and B. fulvus. Yeast: Torula alba. Streptothrix:
Str. Forsteri, Str. chromogenes, Str. albido-flava and an undetermined species. Moulds:
Penicillium glaucum, aspergillus glaucus and aspergillus flavus.
Fresh air.—Five litres incubated in gelatin at 20° C. yielded 44 colonies, of which 40
were bacteria and 4 moulds.
Five litres incubated in agar-agar at 37° C. yielded 5 colonies, viz., 4 bacteria and
1 mould.
The species identified from this 10 litres of air were the following—Micrococci: Sarcina
lutea, sarcina flava, staphylococcus cereus albus and flavus, diplococcus citreus conglomeratus,
M. candicans, M. lactis, M. citreus, M. albicans tardissimus, M. aurantiacus and M. concentricus,
Bacilli: B. lactis innocuus, B. luteus, B. subochraceus, B. latericius, B. arborescens
and an undetermined species. Moulds: Penicillium glaucum, aspergillus flavus and an
undetermined species.
VII.—On May 23rd samples were taken on the up platform at Shepherd's Bush station at
11.40 a.m. A moderate amount of traffic was going on, but the samples were not taken at a very
crowded part of the platform. Temperature 68° F. Barometer 30.46 in. The carbon dioxide was
.094 per cent, and the organic matter .0010.
Fresh air samples were taken in the porch at the exit from the lifts in a small street at the side
of the station. They were taken at a spot freely exposed to the street air, but two or three lifts full of
people came up during the process. It was a dull, damp day, and there had been a good deal of rain
during the preceding night and up to 8 a.m. Temperature, 60° F. Barometer, 304 in. Light W.
wind. The carbon dioxide in the air was .054 per cent, and the organic matter .0014.
The results were as follows—
Platform air.—Five litres incubated in gelatin at 20° C. yielded 112 colonies, viz.,
106 bacteria, 4 streptothrix and 2 moulds.
Five litres incubated in agar-agar at 37° C. yielded 1 colony only, a bacterium.
The species identified from this 10 litres of air was as follows—Micrococci: Sarcina
alba, staphylococcus cereus flavus, M. cremoides, M. candicans, M. coronatus, M. flavus,
M. citreus, M. rosettaceus, M. albicans tardissimus, M. concentricus and M. roseus. Bacilli:
B. latericius, B. ochraceus, B. helvolus, B. luteus and B. carneus. Streptothrix: Str.
chromogenes and albido-flava. Moulds: Two species of penicillium—penicillium glaucum
and another.
Fresh airFive litres incubated in gelatin at 20° C. yielded 93 colonies, viz., 87
bacteria, 1 streptothrix, 1 yeast and 4 moulds.
Five litres incubated in agar-agar at 37° yielded 1 colony only—a mould.
The species identified from this 10 litres of air were the following—Micrococci: Sarcina
alba, staphylococcus cereus flavus and albus, M. rosettaceus, M. aurantiacus, M. flavus and
diplococcus citreus conglomeratus, with an undetermined species. Bacilli: B. latericius,
B. erythromyxa, B. helvolus, B. fulvus, B. lactis innocuus, B. aeris minutissimus, and an
undetermined species. Yeast: Torula alba. Streptothrix: Str. albido-flava and an
undetermined species. Moulds: Penicillium glaucum, aspergillus glaucus, and a mould of
undetermined genus.
VIII.—On May 27th samples were taken at 11.20 a.m. in a non-smoking carriage about the
middle of a train as it was travelling from the Bank to the British Museum station. The carriage
was full, but not crowded. Temperature in carriage 72° F., barometer 30 22 in. The carbon dioxide
in the carriage air was .134 per cent., and the organic matter was .0016.
Fresh air samples were taken at 11.45 a.m. in the open space in front of the British Museum.
It was a fine bright day, with a few clouds and a moderate west wind. It had been fine warm
weather, without rain for four days previously. The temperature was 66° F., and the barometer
stood at 30.10 in. The carbon dioxide percentage was .040, and the organic matter .0016.
The results were as follows—
Carriage air.—Five litres incubated in gelatin at 20° C. yielded 103 colonies, viz.,
90 bacteria, 1 yeast and 12 moulds.
Five litres incubated in agar-agar at 37° C. yielded 4 colonies, all bacterial.
The following species were identified in this 10 litres of air—Micrococci: Sarcina lutea,
sarcina flava, sarcina alba, staphylococcus cereus albus and flavus, M. candicans, M. coronatus,
M. citreus, M. flavus, M. aurantiacus, M. rosettaceus and M. albicans tardissimus.
Bacilli: B. luteus and B. lactis innocuus. Yeast: Torula alba. Moulds: Penicillium
glaucum and a closely allied species, aspergillus glaucus and a species of mucor.
Fresh air.— Five litres, incubated in gelatin at 20° C., yielded 17 colonies, viz., 13 bacteria,
1 streptothrix and 3 moulds.