m 



HEPORT — 1875. 



Breton's Farm. 

 Sewage. — From April 1874 to March. 1875 (botli inclusive). 



In 100,000 parts. 



Ammonia 3'32 



Total Nitrogen (in solution and suspension) . . 5-56 



Chlorine 13-00 



Nitrogen as Nitrates none. 



Efflttent wateb. — In 100,000 parts, 



April, July, October, January, 



May, August, November, February, 



June. September. December. March. 



Ammonia 0-006 0-112 0-004 0-004 



Nitrogen as Nitrates .... 0-78 0-27 0-26 0-56 



Nitrogen not as Nitrates . . 0-13 0-15 0-04 0-06 



Chlorine 10-35 11-45 11-00 9-80 



Total Nitrogen 0-91 0-42 0-30 0-62 



It is to be remarked, in the first place, that the result thus obtained for the 

 total nitrogen of the sewage is very near to the average results already ob- 

 tained ; thus in the year 1871-72 the average was 5-529, and in 1872-73 it 

 was 5-151 per 100,000. And as regards the effluent waters, the total nitro- 

 gen is below the average in all cases, and the purification, as shown by the 

 smaller amount of nitrogen not as nitrates, is more perfect during the last two 

 quarters ; this may be due to the consolidation of the earth around the drain- 

 age pipes ; but the Committee would not now express a decided opinion on 

 this point, as they intend to institute a series of experiments to investigate 

 the changes which go on in sewage and effluent water when kept for some 

 time. 



As 509,139 tons of sewage were utilized on the farm, the total amount 

 of nitrogen supplied was (according to the analysis of the mixed sample) 

 28-38 tons. Last year, from the data obtained from the two previous years, 

 the total amount was taken at 27 tons ; but this year an increase was ex- 

 pected from the fact that more houses have been connected with the sewers. 



The total amount of nitrogen recovered in the crops is estimated at 20,166 

 pounds, or 31-8 per cent, of the nitrogen supplied; in former years the per- 

 centages estimated were as follows : — 



1871-72 41-76 per cent. 



1872-73 26-00 „ 



1873-74 37-60 „ 



The amount this year is exactly the mean of the amounts for the last two 

 years. 



It should be understood that in these calculations no deduction is made 

 for the amount of nitrogen that there would be in the normal unsewaged 

 produce; in other words, the figures show the relation of the nitrogen in 

 the total produce (not in the increase only) to that estimated to be supplied 

 in the sewage. 



The Committee will be able to continue their investigations, owing to the 

 generous liberality of a Member of the Association, and more complete 

 observations arc now going on again systematically at Breton's Farm. 



