ON THE TREATMENT AND UTILIZATION OP SEWAGE. 417 



In the Ecport of the Committee presented at Liverpool it was stated, on 

 the authority of information furnished by the local authorities, that 



(1) The population of Romford was " about 8000 ;" 



(2) That the refuse of about 7000 persons was discharged entirely into 



the sewers ; 



(3) That the whole population is within the area provided with under- 



ground sewers. 



As the Committee had some doubts as to the correctness of these statements, 

 it was thought advisable to have a census of the town, with particulars of 

 sewage connexions, &c. made, and the results will be found in Table VIII. 



Samples of soil were very carefully taken on April 30th, 1873, in presence 

 of Messrs. Corfield, Gilbert, Grantham, Hope, and Williamson, at the same part 

 of the farm as on the previous occasion (July 15th, 1870), when no sewage had 

 been applied to that part of the farm. These samples were mixed, and an 

 average sample was analyzed by Dr. Eussell with the following results : — 



Examination of Soil from Breton's Farm, Sample taJcen April 2,0th, 1873. 



Soil, after drying by exposure to the air, consists of, in 100 parts : — 



Stones too large to pass through holes of a sieve 3-8S millims. 35-77 



Moisture driven off at 100^ C 3-40 



Soil passing through sieve 60'S3 



100-00 

 In 100 parts of the original soil there is : — 



Insoluble in strong hydrochloric acid 55'02 



Loss on ignition (inchides water driven off at 100^ C.) . . 6-65 



Phosphoric Acid (P- 0') 0-058 



Chlorine 0-002 



Ammonia 0-016 



Nitrogen as Nitrates &c 0-00029 



The second part of the above Table represents the percentage amounts (cal- 

 culated from the original soil) of the more important constituents of the G4-23 

 parts of undried soil. Comparing these results -nith those given in the Com- 

 mittee's Second Keport, it will be seen that the phosphoric acid in the soil has 

 increased from 0-01 to 0-058 per cent., that the loss on ignition of the soil 

 is much greater (leaving water out of the question), that the amount of am- 

 monia has been increased from an inappreciable quantity to 0-OlG per cent., 

 and that the amount of nitrates has been also increased. The amount of total 

 nitrogen in the 64-23 parts of soil was estimated by the soda-lime process 

 with the following result : — 



■■o 



Total Nitrogen determined by the Soda-lime Process, 



1st experiment ' 0-191 per cent. Nitrogen. 



2nd experiment 0-187 „ „ 



Mean 0-189 per cent. Nitrogen 



in soil without stones ; therefore in original soil (stones included) 

 = 0-121 per cent. Nitrogen. 



There is therefore no doubt that the quality of the soil has been conside- 

 rably improved by the sewaging, and that a good deal, both of the nitrogen 

 and phosphoric acid, is retained in it, 



1873. 2 E 



