FERTILIZERS. 



763 



former was found to be much more effective as a fertilizer. This is due to the higher 

 percentaiie of nitrogen in the etiluent. The average nitrogen content of the crude 

 sewage at different periods was as follows: 



Nitrogen content of mide senrnje diiriiig (lill'ertnl ni(»iths<. 

 [Parts per 100,000.] 



The richer sewage in >hirrh was due to addition of night soil. In the septic tank 

 the sew'age lost 3 per cent of its nitrogen during the tirst 16'hours, and 4 per cent more 

 in the next 8 hours during December; 10 per cent and 4 per cent, respectively, during 

 January; and 19 and 3 per cent, respectively, in February. With the stronger sewage 

 of INIarch the loss of nitrogen amounted to 22 per cent during the half month. Sim- 

 ilar losses occurred when the etHuent from the septic tank was passed through contact 

 beds, varying from 5 to 40 per cent of the original nitrogen of the sewage. The aver- 

 age composition of the sewage as it left the septic tank was as follows: 



FertUlz'uKj conNlllitents in e(f1ue)it from septic tan/:. 

 [Parts per 100,000.] 



Nitrogen 



Pho.sphorie acid 

 Potash 



4.07 

 1.92 

 1.47 



January. 



3.42 

 1.72 

 1.37 



"If the irrigation rate be assumed as 4,000 gal. per acre per day this sewage would 

 supply 1.5 lbs. nitrogen, 0.73 lb. phosphoric acid, and 0.57 U). potash." 



Influence of the nature of the exterior medium on the mineral composi- 

 tion of plants, A. Hebert and G. Truffaut {Bui. Soc. Chiin. Paris, S. ser., 29 

 {190.i), No. ii4, ])p. 1235-1239). — The authors have already reported investigations 

 (E. S. R., 9, pp. 451, 755; 12, p. 851) from which they concluded that a rational 

 basis for fertilizing was furnished by chemical analysis of typical jjlants grown under 

 normal i-onditions and the determination of the fertilizing constituents furnished 1»y 

 the soil. They here report ash analyses of dracpena, chrysanthemum, cyclamen, 

 and mint grown on fertilized and unfertilized soil, which seem to Ijear out this 

 conclusion in that the mineral composition of the fertilized plants was not as a rule 

 appreciably different from that of the unfertilized plants. 



The authors therefore conclude that for a given species of plant grown on a given 

 soil the use of a complete fertilizer increases the yield but does not affect the mineral 

 compo.sition. However, a special fertilizer like sodium chlorid or nitrate may 

 increase the assimilation of the jirincipal element which the compounds contain 

 without disturbing to any great extent the relative proi)ortions of the other mineral 

 constituents. 



Influence of the nature of the exterior medium on the organic composition 

 of plants, A. Hebert and E. Charabot {Bui. Soc. C'liim. I'aris, 3. ser:, 29 {1903), 

 No. 24, pp. 1239-1247). — Experiments similar to those noted a1)ove were made to 

 determine the influence of various salts of sodium, i)otassium, iron, and manganese 



