234 EXPERIMENT STATION RECORD. 



"Soils containing 1,000 lbs., or over, of phosphoric aciil jK-r acr(», in the npper 4 

 in. of soil, have enongh of this ingredient for large cnjps. ... As the anionnt of 

 this ingredient, in the surface soil, falls materially below 1,000 lbs. per acre, the 

 demand for phosphates is apparent in proportion to the deficiency, provided all other 

 essential conditions for large yields are present. 



"The supply of potash seems to be ample everywhere in the State and we have no 

 evidence that any of our soils require the use of fertilizers containing potash to 

 increase the yields. The results do not indicate the minimum amount of potash in 

 the soil that is adequate for good crops. 



"Nitrogenous fertilizers increase the yields of most of the soils in the State, and 

 where nitrogen is added by growing cowpeas, velvet beans, vetch, and melilotus, 

 which also add organic matter to a soil and improve its texture, results of the most 

 satisfactorj^ kind are obtained. 



"Some of our soil work also indicates that, where the amount of phosphoric acid 

 in a soil is abnormally high, the cotton plant will use several times as much of this 

 ingredient as it needs for normal development. This is probably true of other sub- 

 stances as well. . . . 



"Lime, in large amounts, undoubtedly influences the texture of a soil; it may also 

 have to do with the solubility of the plant food in a soil, but, with good texture, 

 soils will produce well even though the amount of lime present is small. The brown 

 loam soils do not contain much lime, and yet, in proportion to the amount of plant 

 food present, they are probably the most productive lands we have. The texture of 

 these soils is good." 



The construction and use of graded and level embankments and terraces to prevent 

 washing of soils is explained. The reclaiming of washed lands, the value and use of 

 stable manure and restorative crops, and the use of commercial fertilizers are also 

 discussed. 



Bacteriological studies of drinking- water, F. D. Chester {Delaware Sta. Rpt. 

 1900, jyp. 66-76, fgit. ii). — On account of a serious outbreak of typhoid fever in the 

 city of Wilmington attention was directed to a spring from which many people 

 obtained drinking water, and water from this source was analyzed and tested for the 

 presence of pathogenic bacteria. Two organisms were isolated, one a variety of coli 

 bacillus, and another belonging to the hemorrhagic septicfemia or swine-plague group. 

 Details are given concerning the cultural and morphological characters of these 2 organ- 

 isms. Since the organism of the hog-cholera group is closely related to the typhus 

 bacillus, its presence in the water is considered as indicating a faecal contamination. 



"Water from farm homesteads, F. T. Shutt ( Canada Expt. Farms RpU. 1900, pp. 

 191-194). — Tabulated analyses are given of 41 samples of well waters examined 

 during the year. 



FEETILIZERS. 



Basic superphosphate, its preparation and use as a manure, J. Hughes 

 {Jour. Soc. C'hem. Ind., 20 {1901), No. 4, pp. 325-332).— The history of the manu- 

 facture and use of superphosphates is briefly reviewed; tests of the solubility of vari- 

 ous phosphates in weak citric acid (1 part to 1,000 parts of water) are reported; and 

 the preparation of basic superphosphate by mixing slaked lime (15 parts) with 

 ordinary superphosphate (85 parts) is described. The results of tests of the solu- 

 bility of the product in water, weak citric acid, and ammonium citrate (2.5 per cent 

 solution) are given. None of the phosphoric acid was soluble in water, but from 12 

 to 13 per cent was soluble in the weak citric acid (1:1,000) and about 10 per cent 

 in ammonium citrate, being more soluble in these reagents than basic slag. The basic 

 superphosphate is claimed to be especially suited to acid soils or those deficient in 

 lime. 



