130 The Essentials of House Sanitation — 



about what I may call the effluvia pipe. I don't at all agree 

 with the fitting of these pipes. I was very much struck with 

 an observation from a gentleman of experience, that he thought 

 that effluvia pipes were made merely to satisfy the imagination 

 of the householder and not for any practical purpose, because 

 he was informed by a gentleman well versed in chemistry that 

 noxious gases have not the power to ascend, and that they are 

 weightier than the air. If this be a fact, I think it would 

 answer Mr. Brown's question, where does the noxious vapour 

 go to when it gets up to the top .? I may safely tell him that 

 it never reaches the top. On that account I think that these 

 effluvia pipes might be done away with. I am very glad to 

 find sanitary matters taking the attention of the public so 

 much. 



Professor Everett — A great many speakers have expressed 

 the opinion that the open gratings in the streets might with 

 advantage be employed as outlets to ventilate the sewer. The 

 proper pian I think would be not to have air coming in slowly 

 all along the line. Let the air come in at a great distance so 

 that there will be a good rush all along the pipe. We often 

 have to make a compromise between what is best in theory and 

 what is inferior. Some of Mr. Gray's devices would be very 

 good if they were in the hands of sensible and trustworthy 

 people, but I am afraid that some of them, though they would 

 be excellent for skilful and careful hands, are hardly fit to bear 

 the rough usage of ordinary household work, 



Mr. J. Thompson — If tall chimney ventilators are necessary, 

 the draught in them would be improved by erecting furnaces in 

 which the ashpit material could be consumed by using it as fuel 

 lor generating steam, increasing draught, and purifying foul gas 

 as it passes from sewer through fire to chimney. The steam 

 could be disposed of to advantage, while the ashes or slag 

 might be used in making mortar, and a saving would be 

 effected in the removal of ashpit material owing to shorter 

 cartage. 



Professor FitzGerald — I might now call upon Mr. Gray 

 to reply, but there are a couple of points upon which I wish to 



