212 Dr. A. Carpenter on 



on sewage farms, there is an end of their role as disease germs. 

 But if the sewers are sewers of deposit some germs may settle in 

 the pipes; they may fructify there, and their Hving, growing spores 

 be carried away by the currents of air and then discharged to 

 the possible danger of the people. They are not, however, the 

 necessary parts of a sewer system, but are the accidents of 

 defect. I have not the least doubt myself that a stinking 

 grating is not dangerous, from the circumstances I have men- 

 tioned. It is an undoubted fact that the panic in the House of 

 Commons, by which the Metropolitan Board of Works was 

 brought into being, was produced by stinks from the bed of the 

 Thames. It was the healthiest year that London had experienced 

 for a long time, as far as enthetic disease was concerned, at 

 least, if statistics prove anything, and yet the Thames smelt so 

 badly, that our senators could not carry on their work in the 

 committee rooms of the House of Commons. 



Stinking sewers should not be allowed to exist, but to my 

 mind it is better to have the open grids in the streets than to 

 convey the mischief, which is possible, into positions preventing 

 our getting the knowledge that the sewers require to be scoured. 

 Every line of sewer should be well scoured in the crown of 

 its arch as well as at the bottom, and after the scouring, 

 thoroughly flushed by a body of water that fills its calibre 

 completely. The flushing which I see going on in our town 

 from a two- or three inch tube, is all but useless for the pur- 

 pose required, except where there is a stoppago, which produces 

 a head of water and fills up the sewer. Sewers of comparatively 

 small size, in exactly straight sections, so that they may have 

 the lamp test applied, which can be flushed by the sudden 

 discharge of a large body of water at frequent intervals, when 

 the temperature of the sewer rises above a certain point, will 

 remove the colonies of disease germs. They do grow on the 

 sides and invert of the arch of sewers, as certainly as they may 

 be mala to grow in tubes contaiuiag pare solution of gelatine. 

 If the ventilation is tardy, so as to allow of fructification, the 

 colonies give off their spores, and tliese may possibly light upon 

 a passer by, who happens to be infective, and upon whose mucous 

 membrane the organism happens to fall. I say this is a possible 

 contingency but it will rarely happen. These germs are of 

 two kinds : the one is a living, growing orpjanism ; I may 

 compare it to the barley which has been made to sprout in 

 preparation for malting. If this organism be planted on a 

 mucous surface ready for its reception it may take root, repro- 

 duce its kind, and set up its own form of disease ; but, likj 

 the white corpuscles in human blood, exposure to pure air fur 

 a very short period indeed is fatal to it. The fact is made 

 out in the operation called transfusion. If the blood in its 



