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TJic Country Gentlonafi's Magazine 



under unfavourable circumstances. I can 

 easily conceive, unless the ammonia were 

 fixed in the drying processes, the full quan- 

 tity would not be estimated. Beside this 

 there can be no doubt that both the phosphates 

 and the nitrogenous matter would be in the 

 best form for the plant assimilation. It must 

 also be taken into account that a dry system 

 can be adopted anywhere, and be in reach 

 of every farmer, whereas any system of or- 

 dinary sewage treatment can only be done 

 in large towns, tlie carriage from which is an 

 important item to contend with, and may be 

 sufficiently costly to bar its use. 



THE BRITISH ASSOCIATION AND SEWAGE 

 IRRIGATION. 



The latest addition to our knowledge in 

 this direction has been the report of the 

 Committee of the British Association for the 

 Advancement of Science, made at Brighton. 

 Four years ago the Association made a grant 

 of ^lo to investigate the subject. The next 

 year ^^50 were voted, which was supple- 

 mented by grants from various corporate 

 bodies to the value of ;^i53o. The com- 

 mittee begin by reporting their funds as ex- 

 hausted, although the end of their labours 

 was not reached. After touching upon the 

 system of filtration through charcoal of the 

 ]\Iessrs Weare, the effluent water of which is 

 described as diluted sewage, they note Gen. 

 Scott's plan of making a cement from sewage 

 n:iatter and its precipitants by burning them 

 together, thus getting rid of the manurial 

 element quickly, but to the nation at a costly 

 waste. The effluent water here again is said 

 to be diluted sewage. Whitthead's process 

 is more fully descanted on and reported 

 favourably. It consists essentially of the 

 precipitation of the sewage by excessive ad- 

 ditions of mixed phosphate of lime and milk of 

 lime. The process is rapid, the suspended 

 matter as well as much of the organic 

 nitrogen being precipitated. Of course the 

 precipitate containing so much phosphate 

 would be valuable, and if it contains, as 

 asserted, 3 per cent, of ammonia, it is still 

 more so. Here again the effluent water is 

 not pure. In the discussion which followed, 



one learned professor described the report as 

 valueless, and disputed the calculations of 

 the Committee. Another declared they had 

 done nothing, and that no practical result 

 had been given such as would be of any 

 value to the country. It appears that the 

 cost of the phosphates before employment is 

 about ;^4 per ton, and the increase in value 

 after having been made into manure is not 

 more than los. In all their reports much 

 stress has been laid upon sewage irrigation, 

 and doubtless over the extremely limited area 

 over which it is practicable its application 

 will be attended with excellent results. Mr 

 Hope, whose farm at Romford promises to be- 

 come a rival to the famed one at Tiptree, states 

 he has grown So tons of rye-grass per acre, 

 and will soon obtain 100 tons, being able to 

 keep four cows per acre : whereas in the best 

 parts of Cheshire it required two acres at the 

 least to keep one. Professor Corfield as- 

 serted that of the whole nitrogen escaping with 

 the water 40 per cent, went off with the crop, 

 10 per cent, was lost in the drainage, and the 

 remaining 50 per cent, was left in the soil, 

 furnishing food to the plants after the sewage- 

 water was discontinued. Should this state- 

 ment prove correct, it sufficiently indicates 

 the vast importance of sewage irrigation, 

 whilst it shews the great national loss we 

 yearly sustain by allowing even the effluent 

 water of these systems to pollute our rivers. 



DEALING WITH SEWAGE PROFITABLY. 



From what I have said I think it will be 

 evident to every farmer that no system of 

 treating town sewage at present known will 

 make it fcr sc of economical value to him. 

 The best that can be said in its favour is that 

 it may be a good base to which to add am- 

 monia and phosphates from cheaper sources. 

 There can be no doubt that the really valu- 

 able constituents of town sewage are held in 

 solution not suspension, and that these are 

 lost to the community. It is much to be re- 

 gretted that so enormous a waste should be 

 going on at our doors. I trust before many 

 years the combined talent of the chemist and 

 engineer may discover some means of getting 

 over the difficulty which modern fashion has 



