BOTAN!C.'^; 



EXPERIMENT STATION RECORD. 



Vol. 43. Abstract Number. No. 9. 



RECENT WORK IN AGRICULTURAL SCIENCE. 



AGRICTJLTTTRAL CHEMISTRY— AGROTECHNY. 



Chemical reading courses {Jonr. Indus, and Engin. Chem., 12 (1920), No3. 

 7, pp. 701-705; 8, pp. 806-812). — This report of a coiumittee of the American 

 Chemical Society appointed to prepare suitable lists of chemical texts for libra- 

 ries consists of selected lists of boolis covering different phases of chemistry, with 

 brief comment as to the scope of the books recommended. The subjects and 

 compilers of the different lists are as follows : Elementary or Introductory Chem- 

 istry and Household Chemistry, by L. C. Newell ; General and Physical Chem- 

 istry, Inorganic and Analytical Chemistry, and Organic and Biological Chem- 

 istry, by A. M. Patterson ; and Industrial Inorganic Chemistry, Industrial Or- 

 ganic Chemistry, and Techno-Chemical Analysis, by W. Segerblom. 



Optical properties of a series of heptitols, E. T. Whebby (Jour. Biol. 

 Chem., 42 (1920), No. S, pp. S77-S82). 



Sedoheptose, a new sugar from Sedum spectabile, n, F. B. La Forge 

 (Jour. Biol. Chem., 1,2 (1920), No. 3, pp. S67-374). 



The absorption spectra of the nitric esters of glycerol, E. Q. Adams 

 (Jour. Amer. Chem. Soc, 42 (1920), No. 7, pp. 1321-1327, figs. 3). 



Volemite, F. B. La Forge (Jour. Biol. Chem., 42 (1920), No. 3, pp. 375, 376). 



Acidity of ash-free and of commercial gelatin solutions, H. E. Patten 

 and T. O. Keixems (Jour. Biol. Chem., 42 (1920), No. 3, pp. 363-366, fig. i).— A 

 continuation of the study previously noted (E. S. R., 41, p. 11). 



Cockle-bur oil, a new seed oil, L. B. Rhodes (Jour. Amer. Chem. Soc., 42 

 (1920), No. 7, pp. 1507, 1508). — The kernels of a variety of cockle-bur known as 

 the clot-bur (Xanthium echinatum) yielded on heavy pressure in the cold be- 

 tween steel plates 29.89 per cent of a light yellow oil, of a pleasant odor and 

 taste. The following constants were obtained : Specific gravity at 15.5° C. 

 0.9251, refractive index at 15.5° 1.4773, Zeiss butyrometer at 20° 1.4771, refrac- 

 tometer at 40° 1.4691, solidification point — 18°, iodin number (Hanus) 140.8, 

 saponification number 190.2, Reichert-Meissl number 0.233, Hehner number 89.7, 

 acetyl value 10.6, and melting point of the fatty acids -f 19°. 



Samples of raw linseed oil and cockle-bur oil under the same drying condi- 

 tions required four and five days, respectively, to reach the same degree of 

 dryness. The meal remaining from the extraction of the oil was found to be 

 highly toxic. 



Pappea seeds of South Africa as a source of oiU (Bui. Imp. Inst. [Lon- 

 don'\, 17 (1919), No. 4, pp. 488-491). — The seeds of Pappea capensis, the fruit of 

 which is known as the South African prune, were found to contain 7.4 per cent 

 of moisture and to yield 47.8 per cent of a viscous oil of golden yellow color. 

 The analytical constants of the oil were as follows: Specific gravity at 15° C. 

 0.915, solidifying point of fatty acids 39.5° C, acid value 13.1, saponification 



801 



