88 



BACTERIA IN THE AIR 



times more bacteria than the air of a typical above-ground bake- 

 house.* 



Dr Scott Tebb has also made a somewhat parallel examination 

 of the air of London streets as compared with the railway tube of 

 the City and South London railway.f As the result of a large 

 number of investigations carried out in a similar way to the writer's 

 examinations in bakehouses, the following figures were arrived at : — • 



(ui.) Thirdly, some of the results of the investigations of Graham 

 Smith into the condition of the atmosphere of the House of Commons 

 may be mentioned.:}: He used a modification of Frankland's method of 

 filtering the air to be examined (4'5 litres in each case) through glass 

 wool. An air-pump and a rubber tube of 10 feet in length were 

 used for drawing the air through, and gelatine was used as the 

 medium, the cultures being incubated at 20° C. for five days or 

 longer. The results may be expressed in tabular form in three 

 series : — 



Experiments on Outside Air, IStli July. 



Position. 



No. of 



Bacteria and Moulds 



per litre. 



No. of Moulds 



only 



per litre. 



1. Terrace (ground level) . 



2. „ (10 feet from ground) 



3. „ (20 feet from ground) 



4. Clock Tower (half-way up) . 

 6. „ (top) . 



6. Peers' Inner Co 



7. Star Court 



.^ourt 



4-2 

 2-9 

 3-3 

 1-5 

 1-3 

 4-2 

 6-0 



1-1 

 1-1 

 2-0 

 0-2 

 0-6 

 0-6 

 1-3 



Similar experiments were performed in the House itself during a 



* Seport ore Bakehouses in Finsbury (Newman), 1902, p. 51. 



t Report of Public Analyst ofSouthwarJc on Condition of Air on City and South 

 London Railway, 1903. W. Scott Tebb, M.D. 

 t Jour. ofHyg., 1903, pp. 498-513. 



