278 LIFE AND EXPERIENCES CHAP. 



vessels which were placed in an underground chamber 

 excavated in the Speaker's garden. As soon as one 

 of these is filled, air pressure is automatically put on, 

 and the whole of the contents of the vessel pass through 

 a pipe directly into the main sewer, so that there is 

 absolutely no connection between the main sewer on the 

 Embankment and the drains of the Palace of Westmin- 

 ster. As regards the sewers, all risk of contamination 

 of the air from outside sources is now avoided. 



In addition to this, many improvements were made 

 in the ventilation of the Palace at my suggestion, 

 especially with regard to the filtration of the air, 

 and I made experiments on the composition of the 

 air entering the building before and after filtration 

 through cotton-wool. I determined the number of 

 micro-organisms present, and showed that a con- 

 siderable diminution of these organisms occurred by 

 the filtration of the air. The Speaker, Mr. Peel, 

 was much interested in these experiments, and I 

 exhibited to him the results we obtained. I may 

 add that my late friend Carnelley, whose premature 

 death science had subsequently to deplore, made 

 some interesting observations on the number of 

 organisms present in the air of the main sewer in the 

 building, and, corroborating the results of other 

 experimenters, he found the somewhat remarkable fact 

 that in the sewer air the number of microbes is very 

 much smaller than in the air of the street above, 

 doubtless due to the fact that, the surface of the sewer 

 being moist, the microbes remain in the liquid, 

 whereas in the street, the air being dried, the 

 microbes float about in the dust. 



As regards my Parliamentary efforts in the cause of 

 technical education an account has already been given 

 in Chapter VIII. 



