182 REPORT 1871. 



face of lower lands with a view to its further purification. The sewage as it 

 passed off the fii'st surface was observed to be far from clear to the eye, and 

 it was not perfectly so when leaving the second surface. When it was ulti- 

 mately discharged at the outfall it was still cloudy, but this was partly 

 accounted for by the heavy rains of the previous day. The analyses of sam- 

 ples of efiluent water taken at different points, hereafter referred to, will show 

 the extent of purification effected. 



Though the land had not been drained, it gave indications of a natural 

 capabihty of drainage in the escape of the sewage from the sides of the car- 

 riers or drains, which are from 10 to 14 inches deep. The line of saturation 

 was clearly shown in those shallow cuts to be nearly identical with their 

 depth, and the liquid was seen oozing out of the land at some parts in a 

 clarified condition, and at others accompanied by a slimy matter, some spe- 

 cimens of which have been microscopically examined by Mr. M. C. Cooke, 

 M.A., whose report is here given. 



Microscoiiical Examination of Slime and Mud from Bottom and Sides of 

 Carriers at Earhwood Farm. 



The fluid specimen of deposit sent to me for microscopical examination was the 

 only one in a fit condition to report upon as to " the insects and animalcule to be 

 found therein." Obviously dried mud would give no satisfactory result as to living 

 animals, since the majority of them wovddbe dead and shrivelled beyond all power 

 of determination. 



I have examined the wet deposit by the aid of the microscope, and find it to 

 contain a few Diatoms belonging to several genera and species, but in a compara- 

 tively small proportion to the volmne of material. The Desmidiaceaj were also 

 represented by a species of Closterimn, of which I detected but a few individuals. 

 Confervoid threads were also but sparingly scattered through the mass. Altogether 

 there was_ a smaller percentage of unicellular Algse than I expected to have 

 found. Living vegetable matter was comparatively rare. 



The animal inhabitants of the mud were numerous, especially of certain Muds. 

 There were _ a few examples of that common Thysanurous insect, Achorutes aqva- 

 ticus, sometimes so plentifid in the liquid draining from heaps of manm-e. The 

 larvfe and pupaj of small Diptera I am unable to name in those stages, hut their 

 proportion was not large. OiEuglena viridis there was no lack ; and any stagnant 

 puddle, especially in the neighbourhood of farmyards, would have yielded an equal 

 proportion. Infusorians were scarce ; a few solitary individuals of Vorticella mi- 

 crostoma, and one or two specimens of Paramecitim, were about all that I observed. 

 But there was one gi-onp of animal organisms most abundantly represented, and 

 these were the Annelids. When the mud was exposed to the light and sun, the 

 surface became active with these creatm-es ; about the diameter of a piece of 

 cotton-thread, and from half an inch or less to nearly 2 inches in length, they 

 wa-iggled over the_ whole surface. Some white, others pink, and a few of a deep 

 blood-red were mingled together like eels, wriggling and scriggling in every drop 

 that coidd be taken up and placed on a slide for examination. Skins without in- 

 habitants were almost as plentiful ; and it seemed to be impossible to get a drop of 

 the material in the field of the microscope without either the worms themselves or 

 empty sk-ins. (Signed) M. 0. Cooke, M.A. 



It appears to the Committee that the existence of the exuded matter de- 

 scribed by Mr Cooke is mainly, if not whoUy, due to the fact that the subsoil 

 is kept in a saturated condition by the want of underdraining ; and they desii'e 

 to add their behef that with land thus saturated with sewage certain atmo- 

 spheric conditions exist which may be attended by malaria more or less in- 

 jurious to health. It need hardly be said that if the efiluent liquid passing 

 from a sewage-farm at a time when vegetation is in a luxuriant state, and 

 waen evaporation is more than ordinarily active (which was the case when 



