147 



treated with the surface irrigation will not be wholly 

 overlooked, so that a larger portion of the three thousand 

 dollars' worth of plant food contained in the annual flow 

 from this institution may be used. 



This valuation is shown in the following calculation 

 contributed by J. Q. Evans, a member of this committee: — 

 At our request samples of this sewage were taken 

 and analyzed by Dr. Guessman, and a review of the fig- 

 ures are most interesting. All the sewage from this 

 Hospital containing one thousand people, together with 

 the water from the sinks and washrooms amounts to one 

 hundred and fifty thousand gallons daily. 



This sewage contains in million partes, nitrogen, 28 

 parts; potash, 33 parts; phosphoric acid, 12 parts. 



An estimate for a day's run shows that 33.6 lbs. of nitro- 

 gen, 39.6 lbs. of potash, and 14.1 lbs. phoshoric acid are 

 each day carried away in the sewage from this institu- 

 tion ; while in a year there is the enormous loss of 12,226 

 lbs. of nitrogen, worth at 15 cents per pound — $1,839.60, 

 14,445 lbs. potash worth at 5^ cents per pound— 1794.47, 

 5,256 lbs. phosphoric acid worth at 7 cents per pound — 

 f 367.92, a total value of over $3,000 of plant food in the 

 sewage. Compared with one of the best known brands 

 of commercial fertilizer, this sewage for one year con- 

 tains more nitrogen than is found in 200 tons ; more 

 potash than is found in 100 tons ; and more phosphoric 

 acid than is found in 20 tons of such commercial fertilizer.- 

 It will be noted that this sewage is especially rich in 

 nitrogen, and to this is undoubtedly due the lodging of 

 grass crops ; excess of nitrogen causing a rank growth of 

 a soft nature, while the small amount of phosphoric acid 

 mighG fail to produce a full amount of grain in proportion 

 to the straw in such crops. 



One of the difficulties to a better use of this sewage 

 has been the naturally moist condition of the soil, which 

 is of a heavy clayey character, the water not leaching 

 down readily. Dr. Page is at present engaged on a field 



