AiGlsT 21, I1I03.] 



SCIENCE. 



247 



ing the heiu]) seed in bluestoue solution will 

 kill the rape seeds, but not the hemp. Water 

 heated to 140° F. appears not to hurt hemp 

 seeds, but the rape seeds are destroyed by 

 this temperature. It is found that the rape 

 seeds maintain their vitality for at least thir- 

 teen years in the soil. Professor Garman in- 

 sists upon it that by the use of improved 

 machinery the rape seeds may be largely re- 

 moved from the hemp seed. The application 

 of lime, salt, etc., to the soil is found to have 

 no value. 



THE STUDY OF GALLS. 



Some time ago a notice was made in these 

 columns of a book of Edward Connold, of 



(Jails.' It is the intention of Professor Cook 

 to continue this work, enlarging the scope of 

 his inquiries until he has material enough for 

 an extended publication. We may, therefore, 

 confidently expect an American volume com- 

 parable to Connold's British volume referred 

 to above. 



Charles E. Bessey. 

 I'xivEK.siTY OF Nebraska. 



' (lliAPHWS OF THERilODYSXillCS: 

 Messrs. Bates and Welborn, in the Sibley 

 Journal of Engineering , present an interest- 

 ing study of the relations of five gas-engine 

 type-cycles and graphically exhibit their char- 

 acteristics in three-dimension diagrams which 



C'liaracteristies of Cycles 



England, entitled 'British Vegetable Oalls,' 

 and the suggestion was made that in America 

 this field of inquiry is practically uninvaded. 

 We are glad to know that Professor M. T. 

 ("ook, of DePauw University, has been giving 

 attention to these structures for some time. 

 We have before us two bulletins issued by the 

 Oliio State University devoted to ' Galls, and 

 Insects Producing Them," by Professor Cook. 

 This article is a preliminary publication 

 which promises a much more extended publi- 

 cation in the future. The article as at present 

 published includes ' Morphology of Leaf 

 Galls,' 'Apical Bud Galls," 'Lateral Bud 

 Galls.' ' Stem Galls ' and ' Development of 



strikingly illustrate the text.* A common 

 compression line is assumed and the same 

 amount of work is performed by each cycle; 

 all performing similar work with similar heat- 

 sujiply, under these conditions, as indicated 

 by Rontgcn's theorem. 



All heat-engines employing a perfect gas as 

 working substance, in a cycle composed of a 

 pair of adiabatics crossed by a pair of isodia- 



* Sibley Journal of Mechanical Engineering, 

 •Iiuie, 1903, p. 372. Vide ' Tlieriiial Lines on 

 Isometric Planes,' Siblcg Jourmil, February. 1000, 

 l>v K. II. T.; 'Graphic Diagrams and Glyptic 

 .Models,- ./(iiir. l-rii„kHn liisl.. .T;UHi:iiy. ISnC. l>y 

 I!. H. T. 



