188 Air and Water Poisoning 



The suspended organic matter as shown on microscopic 

 examination consisted entirely of those plants and animals 

 which live in pure water, viz. : — Monads, rotifers. 



Desmids, micrasterias furcata and pinnatifida, stauras- 

 trum gracile, paradoxum and orbiculare, arthrodesmus incus, 

 ■docidium qy. truncatum, &c. 



Their were no fungi or confervae of any kind, and the 

 absence of all animalcules of the kolpod group was also 

 marked. 



I proceed now to collate these results, and to consider how 

 far they afford material for arriving at definite conclusions 

 relative, first to the efficacy or value of the filtration cess- 

 pits (the principal question submitted to me), and after- 

 wards to some points bearing on the relation of the present 

 system of drains and cesspits to the public health, as illus- 

 trated by this investigation. 



Two filters were examined, and one of them (the largest) 

 was sampled several times. It was also opened, that its 

 internal arrangements might be seen, and their condition 

 and operation noted, as I had reason to doubt whether, in 

 the strict sense of the term, it was a filter at all, or only a 

 strainer. The suspicion that it was chemically inoperative, 

 and mechanically incomplete, was fully borne out. Pieces of 

 solid matter, meat, were seen proceeding from it, and one of 

 them which, when moist, was as large as a filbert was pre- 

 served. It appeared that the current of water had worked 

 •channels through the whole body of the .filter. These 

 channels were many in number, and the water flowing 

 tlnrough, carried with it portions of the charcoal of which 

 the filter was in part composed, and there was a layer of 

 this charcoal on the top of the upper grating, outside the 

 filter, which was said to be composed of 6 cwt. animal char- 

 coal, 12 bags wood charcoal, and 1 load of oyster-shells, 

 with a layer of road-metal at top and bottom, the whole 

 enclosed by the two iron gratings. A stick was inserted 

 and easily stirred about for a depth of a foot in the filter, 

 showing its disintegration. The cesspit in connection with 

 this filter (the lower one) received, in addition to the con- 

 tents of the closets, the washings of the kitchen. I was in- 

 formed that the present filter (III) was relaid 18 months before 

 the examination, and that when it was then opened the 

 cesspit only contained 3| feet deep of solid matter, repre- 

 senting the excreta of sixty or seventy persons ! At the 

 time of the present inspection the rough test of taking 



