58 A Solution of the Sewage Problem. [January, 



Bills, on the 15th and 25th of March, 1870. He states 

 that, taking the condition of the sewage put upon the land 

 at Croydon, Norwood, Beddington, Rugby, Carlisle, and 

 Worthing, the average proportions of matter in solution in 

 the sewage, before it was put upon the land, was 32*77 

 grains. As it ran from the land it contained 34*3 grains, 

 there being an increase in the solid matter after flowing 

 through the land. The necessary conditions for irrigation, 

 which he admits are not always present, are porous soil and 

 good subsoil drainage. Frozen soil will not allow the 

 sewage to sink, and a heavy rainfall will prevent it; and Dr. 

 Letheby's experience has shown him that the land acts upon 

 the sewage only at the time of active vegetation, " but that 

 during the time of the dormant state of the vegetation the 

 sewage runs off that land pretty nearly as it goes on it." 

 He shows that, besides the acre of land for every 100 people, 

 there must be another acre in reserve when that cannot be 

 doing its work. The chief objections he considers to be, in 

 the first place, the saturation of the soil with excrementitious 

 matter, which is constantly giving off — sometimes to a great 

 extent, at other times not so much — "effluvia capable of pro- 

 ducing disease. Secondly, "the subsoil water is always 

 charged with decomposing matters, the residue of the 

 sewage ; and we know from the investigations recently of 

 Dr. Pettinkoffer, who has examined into the question in 

 England and Germany, and almost all over the world, that 

 there is no more fruitful source of disease than a subsoil 

 water charged with offensive matters, and altering in its 

 level. The soil becomes filled with offensive gases, and he 

 traces cholera and typhoid fever to these emanations, and 

 he attributes epidemics to these emanations. Again, we 

 have subsoil water which runs into the neighbouring wells, 

 and whenever there is subsoil irrigation the neighbouring 

 wells are offensive." ..." There is another objection, which 

 I look upon as the most serious of all : parasitic diseases in 

 the human body are always derived from parasitic diseases 

 in the flesh of the animals we eat. I hold in my hand 

 a report from the most experienced man in this subject, — 

 I may say in the world, — Dr. Cobbold. It treats of the 

 more . than probable, the certain, introduction of serious 

 parasitic disease among the community, if sewage be put 

 upon land as a means of utilising it." 



These are the objections to the utility of the process of 

 irrigation merely as a means of disposal of the sewage, — and 

 they are very great, — whilst as we before observed, as to the 

 equally important question of utilisation, its claims are very 

 small indeed. 



