RECENT WORK IN AGRICULTURAL SCIENCE. 



AGRICULTURAL CHEMISTRY— AGROTECHNY. 



Practical physiological chemistry, P. B. Hawk (Philadelphia : P. Blakts- 

 ton's Son & Co., 1918, 6. cd., rev. and < nl., pp. XIY+661, pis. 6, figs. 185).— This 

 is the sixth edition of the volume previously noted (E. S. R., 35, p. 311). The 

 chapters on metabolism, blood analysis, gastric digestion, and quantitative 

 analysis of urine have been expanded, and a new chapter on acidosis has been 

 introduced. In the quantitative section. Van Slyke's procedure has been 

 adopted as the sole method for the determination of acetone bodies in the 

 urine, and the use of urease for the determination of urea. Several new 

 illustrations have been added. 



The globulins of the jack bean, Canavalia ensiformis, J. B. Stmnee (-lour. 

 Biol. Chcm., 37 (1919), Wo. 1, pp. 137-142, pi. 1).— By subject in:: Jack beans t.. 

 dialysis the author lias separated three globulins in place of the two found by 

 Jones and Johns (E. S. R., 37, p. 8). Bisphenoid crystals, to which the name 

 concanavalin A has boon given, are precipitated first: a noncrystallizahle globu- 

 lin, canavalin, separates next as spheroids; and finally a small amount of 

 material crystallizes in the form of i dlea This last has been named con- 

 canavalin B. By filtering off the precipiiai. b as they appear, a partial separa- 

 tion of the globulins can be made, but a more comp mration is brought 

 about by the use of salt solutions. Canavalin is readily soluble in 1 per cent 

 sodium chlorid solution, concanavalin B slowly soluble in 10 per cent salt solu- 

 tion, and concanavalin A Insoluble in any but concentrated salt solutions. 



All three globulins are said to give the usual protein color ami precipitation 

 tests when purified. 



New reflux condenser. J. J. Ba.tpa (Jour. Indus, and Engin, Chem., 11 {1919), 

 Xn. 1. p. 52. fig. J). — A modified type of reflux condenser is described which is 



said to be very satisfactory, eS] ially in those cases in which the rofiuxing 



liquid has a comparatively high boiling point. 



The modification consists of a vapor conduit forming a part of the condenser 

 through which the vapors pass and are led Into the upper part of the condensing 

 coil. At the lower end of the coil is a trap by means of which is provided 

 regular and undisturbed flow into the receiver. 



Absorption pipettes, E. Van Axstine (Jour. Indus, and Engin. Chcm.. 11 

 (1919), A'o. 1. pp. 51. 52. fig. 1). — An absorption apparatus to be used with the 

 Parr carbon apparatus for determining both carbonates and total carbon in 

 soils is described and illustrated, in which the use of glass beads or class rods 

 is dispensed with by means of a siphoning device enabling tin 1 L-a< to come in 

 close contact with the absorbing liquids. It is stated that it is not necessary 

 to shake the apparatus to insure rapid action, as must lie done when bulbs 

 without beads or rods are used, yet absorption is as rapid as with either. 



The wet process for the determination of carbon. YV. STF.rr (Binrhrm. 

 Ztsrhr., 87 {1918), No. 5- J. pp. U5-U2, flfj. 7 V— Pertain improvements in the 

 wet method of estimating carbon are suggested. These include slight modifi- 

 cations in the apparatus and more careful purification of the reagents era- 



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