406 KEPOET— 1891. 



The operations at the farm for the last year show a profit 

 of £54 OS. 8d., and it is expected that better results will be 

 obtained when the supply of sewage increases, and more land 

 is prepared for treatment. 



Of all modes of disposing of sewage in a healthy and profit- 

 able manner, none can compare with filtration through and 

 irrigation over the land. As each year passes the tendency 

 seems more and more to favour this method. It is only neces- 

 sary to refer to the recent Sanitary Congress at Brighton, and 

 the able paper on the purifying qualities of the earth, read 

 at it by Dr. Vivian Poore, to be convinced of this fact. 



Charges have been made against sewage farms as being 

 injurious to health; but when the sewage is delivered in 

 moderate quantities, and before important putrefactive 

 changes have occurred, no danger need be feared. The 

 milk and butter from cows fed on sewage-raised food com- 

 pare favourably with other samples, while vegetables grown on 

 sewage farms are of excellent quality. When the members of 

 the Association visit our farm they will see for themselves that 

 cattle thrive amazingly on the grass raised by sewage off 

 common sandhills. These sandhills, which were perfectly 

 worthless, will in time produce large quantities of excellent 

 crops, although at present it cannot be contended that the 

 filtration is as effectively performed as would be the case in 

 good mould. 



The following analysis, made for us at the Colonial Labora- 

 tory, Wellington, by Mr. Skey, shows that in the passage of 

 the sewage through the sand a certain amount of ammonia 

 has escaped conversion, which would not have happened in 

 better land : — 



Analysis. 



1. Sewage. — Colourless and turbid, with tlie odour of putrefaction. 



2. EfHuent water after No. 1 had been passed through the paddocks, 

 and as discharged into the estuary. 



The following results were obtained upon them as computed in 

 grains per gallon : — 



No. 1. No. 2. 



Ammonia .. .. .. 0-16 .. 0-02 



Organic matter* . . . . . . 10-21 . . 4-21 



Mineral saltsf .. .. .. lO'Sl .. 10-12 



21-13 14-35 



* No. 1 containing nitrogen 0-51gr. ; No. 2, 0-lGgr. 

 t No. 1 contains 0-21gr. of phosphoric acid and 0-76gr. of potash ; 

 No. 2 contains traces of this acid only, and 0-31gr. of potash. 



The precise nature of the rest of the mineral substances in these 

 waters has not been determined, but as far as was shown by qualitative 

 analysis they appeared to consist in each case mainly of alkaline chlorides 

 and sulphates. 



These results show that the sewage has been very largely deprived 



