SEWER GAS AND DISEASE 365 



There has always been considerable discussion on the 

 exact relation of " sewer-gas " to disease. It is generally 

 held that sewer-gas is at least a predisposing cause to 

 enteric fever, diphtheria and tonsillitis. Some have 

 considered that the specific organisms are present in the 

 emanations from sewers, and this may occasionally be 

 the case. Thus Horrocks, 1 in some experiments performed 

 at Gibraltar, by pouring sewage artificially infected with 

 typhoid culture down drains, showed that specific bacteria 

 present in sewage may be ejected into the air of ventilation 

 pipes, inspection chambers, drains and sewers by (a) the 

 bursting of bubbles at the surface of the sewage, (6) the 

 separation of dried particles from the walls of pipes, 

 chambers and sewers, and probably by (c) the ejection of 

 minute droplets from flowing sewage. " Sewer- gas " may 

 also lower vitality and increase susceptibility. Thus Alessi 

 found that animals exposed to drain emanations are at 

 first more susceptible to infection, but after a month or 

 so acquire tolerance and are no more susceptible than 

 animals kept under ordinary conditions. Exposure to 

 the gaseous emanations from putrefying matter is stated 

 by Trillat to increase the virulence of pathogenic bacteria. 

 There is no evidence that sewer-men or those employed at 

 sewage-works suffer from ill-health. 



Action of heat, germicides, etc. The B. typhosus in broth 

 culture is killed by a temperature of 53-54 C. in half an 

 hour, and of 56-60 C. in ten minutes. It is readily 

 destroyed by antiseptics. (See Table, Chap. XXII.) 



Semple and Grieg (loc. cit.) found bright sunlight to be 

 germicidal in from two to six hours. 



Wines and spirits have some germicidal action on the 

 typhoid bacillus. Champagne destroys the bacillus in 

 ten minutes, white wines in fifteen to twenty minutes, 

 red wines in thirty minutes or thereabouts. If diluted 



1 Journ. Roy. San. Inst., May 1907, j>. 176. 



