378 



SCIENCE 



[N. S. Vol. LII. No. 1347 



are applying our sulphur fertilizers at the 

 wrong place in the rotation when we use them 

 with the cereal grains which require little sul- 

 phur. Top dressing in legumes would be the 

 logical time in the rotation to provide the sul- 

 phur when it is known to be deficient in 

 amount. 



While the results obtained by Eeimer are 

 certain not to be duplicated on certain types 

 of soils in the eastern United States, as for 

 instance on soils deficient in lime, or on acid 

 soils, the results indicate that it is worth while 

 to test out the value of sulphur generally 

 through the country. The fact that the early 

 users of gypsum over a century ago had similar 

 results with soils in Pennsylvania and Vir- 

 ginia should encourage renewed experimenta- 

 tion with sulphur fertilizers, under conditions 

 that preclude confusing one limiting factor 

 with another. As already suggested, the early 

 failures were probably caused by the soils be- 

 ing deficient in phosphorus rather than sul- 

 phur in some cases, or deficient in both at once, 

 or at any rate not in sulphur alone. 



We know enough now to make our tests 

 crucial as to which element or elements limit 

 production. The only way we can know the 

 facts will be by actual tests. The system of 

 soil fertility upon which our vast expenditure 

 for fertilizers is based should be examined and 

 tested with open unprejudiced minds. The 

 tests of sulphur containing fertilizers should 

 be made over wide areas in the eastern United 

 States, for there must be many soils in which 

 sulphur is deficient for optimum nutrition of 

 high sulphur-requiring plants. In many cases 

 where superphosphate has been used with suc- 

 cess, it may be the sulphur, rather than the 

 phosphorus that is the valuable element. In 

 such cases substitution of the cheaper gypsum 

 might yield as satisfactory results as the more 

 expensive fertilizer. 



American agriculture would be vastly bene- 

 fitted by extensive experimentation along the 

 lines suggested, with strictly controlled condi- 

 tions under which alone can we have a proper 

 interpretation of results. With our expendi- 

 ture for fertilizers much in excess of a hun- 

 dred million dollars annually, it is highly im- 



portant that our fertilizer practise should be 

 put upon a rational basis at the earliest pos- 

 sible moment. 



Charles A. Shull 

 XJNrvERsiTY OP Kentucky, 

 Lexington, Kt. 



ERIC DOOLITTLE 



Eric Doolittle, Flower professor of astron- 

 omy and director of the Plower Astronomical 

 Observatory died September 21, 1920. In 

 1917 he was called upon to organize and con- 

 duct the U. S. Shipping Board Navigation 

 School at Philadelphia. In attempting to 

 teach the large number of men suddenly thrust 

 upon him and to attend to the correspondence, 

 registration and other necessary details with- 

 out assistance, none being provided or iimne- 

 diately available, he greatly overtaxed his 

 strength and collapsed under a slight stroke. 

 Although later he was able to resume his 

 university duties, he never fully recovered 

 and did but little observing thereafter. In 

 May, 1920, he became ill again. When his 

 condition became serious he was removed to 

 the University Hospital on June 24, at which 

 place he died. 



Professor Doolittle was born in Indiana in 

 1870. In 1876 his father, C. L. Doolittle, 

 became professor of mathematics and astron- 

 omy at Lehigh University. The son gradu- 

 ated there as a civil engineer. After prac- 

 tising this profession for a year he was 

 instructor in mathematics at Lehigh for a 

 year and at the University of Iowa for two 

 years. After spending a year in graduate 

 work in astronomy at the University of Chi- 

 cago, he became instructor in astronomy at 

 the University of Pennsylvania in 1896, where 

 his father has been called in the meantime 

 as professor of astronomy. 



The Flower Observatory was established in 

 1896. Eric Doolittle was placed in charge of 

 the new 18-inch refractor with its superb 

 Brashear lens. The telescope was made with 

 a long focus, 30 feet, for double star observa- 

 tion. He immediately began his observations 

 of double stars. He used the telescope almost 



