in Melbourne. 181 



found to be a growing practice to build houses with drains 

 and pipes of this kind ; and the double offence of wasting 

 water and turning the street into a cesspit, or the cesspit 

 into the street, was common and familiar. The labour was 

 in finding out the cases, and in watching the offenders after- 

 wards to see that they did not recur to the practice, as was 

 often done. 



But still greater difficulties were presented by a refine- 

 ment which stood in loco parentis to the practice just 

 described. I allude to the filtration system, of which 

 Dr. Tracy was the apostle. This gentleman (and others who 

 adopted the plan) professed, and no doubt believed, that it 

 fulfilled all the required conditions. How they could 

 possibly arrive at such a conclusion it is difficult to conceive ; 

 and it may be doubted if many who adopted the method 

 troubled themselves with any view at all. But Dr. Tracy 

 publicly recommended it as efficacious, and spent much 

 money in fitting up his own ; and it was also introduced 

 into a public institution where he holds a prominent posi- 

 tion. The existence of filters, examples of which were 

 tolerated for a time, encouraged the construction of others, 

 and what was still worse, furnished to many persons a 

 pretext for flushing, under the pretence of filtering. 



In view of all these and other difficulties that beset the 

 •endeavour to stop these practices, the City Health Committee 

 did me the honor to desire an investigation and report upon 

 the several branches of the subject. The experiments made 

 and observations recorded while carrying out these instruc- 

 tions are embodied in the present paper. 



After conference with the health officer, I visited, at 

 different times, several places that required examination in 

 connection with this subject, in order to select and obtain 

 the necessary samples for analysis. 



Instead of limiting myself to the examination of a number 

 of samples to be furnished to me, I preferred visiting the 

 places myself, and when doing so, took a large number of 

 samples, and made such use of each as I deemed judicious 

 for the advancement of the objects in view, viz. : — 



First. The determination of the efficiency or non-efficiency 

 of the filtering system of cesspit draining ; and secondly, 

 the detection of sanitary evils which, not being detectable 

 by ordinary methods, did not come under the common 

 description of nuisances. 



I do not therefore confine myself here to the bare state- 



