THE ALUMNI JOURNAL, 



247 



molecule being at all affected. A new glucoside 



is thus produced very similar to amygdalin of 



the formula: 



C G H,. CH. CH 



I 

 0. C c H n O, 



He calls this glucoside " amvgdonitrile glu- 

 coside. " It closely resembles amygdalin in 

 chemical behavior, but diners very much in 

 physical properties. To prepare it, 10 grms. of 

 finely powdered amygdalin are mixed with cpcc. 

 of a solution, in which i part of well washed 

 and air-dried brewers' yeast is mixed with 20 

 parts of water and kept at 35 for 20 hours. To 

 prevent secondary fermentation reactions .8 

 grammes toluol is added. The mixture is then 

 kept in an incubator at 35 for a week. The 

 details of purification must be left for reference 

 to the original paper (Ber. xxviii. 151 1 ). The 

 pure glucoside begins to decompose at 140 , 

 and is completely melted at 147 to 149 . Its 

 specific rotation is 



20° 



[a] = — 26.9 

 d 



It has a bitter taste, much stronger than amyg- 

 dalin; it is easily soluble in cold water, alcohol, 

 and acetone, and can thus be easily separated 

 from amygdalin. It dissolves in 20 parts of hot 

 acetic ether and in 2.000 parts of chloroform, 

 which forms a useful menstruum to re-crystallize 

 it from. Fehling's solution is not altered by it. 

 Emulsin rapidly decomposes it into] benzoic 

 aldehyde, hydrocyanic acid and one molecule 

 of glucose.— Br. Col. Dr., Aug.. '95, pg. 171. 



The Purity of Balsam of Copaiba.— Accor d- 

 ing to Enell (Nord. Farm. Tidskr.), a sample 

 of copaiba balsam is pure so long as it passes 

 the following tests : ( 1 ) A mixture of 4 cc. of 

 acetic ester and two drops of concentrated sul- 

 phuric acid are added to six or eight drops of 

 the sample ; no red or violet color should be 

 developed in 15 minutes. If no distinct color is 

 formed, a few drops of water are added, and the 

 whole shaken ; no red sediment should appear. 

 ( 2 ) When heated in a porcelain capsule no odor 

 of turpentine should be perceptible. (3 ) A sam- 

 ple should be heated carefully to 150 C, and 

 one gramme of the residual resin is heated with 

 5cc. of ammonia ^neither a viscous slime nor a 

 solid mass should result, even after standing for 

 24 hours in a closed vessel. (4) Two parts of 

 copaiba and one of ammonia are warmed in a 

 test tube, The mixture should be clear, even 

 after cooling on ice for 15 minutes.— Apotheker 

 Zeitung. 



PLANT CONSTITUENTS. 



BY HENRY KK.KMEK, I'll. G. 



The formation and localization of the 

 different plant constituents, their relation 

 to each other and their functions in the 

 vegetable economy have been subject to 

 much thought and experiment, and at 

 the same time, of some rather absurd 

 speculation. It is of the highest practical 

 importance to us all that the constituents 

 of the plants be determined and that their 

 localization, formation and functions be 

 perfectly understood. Plant chemists 

 have been at work a great many years 

 with their analyses, and botanists are now 

 ascertaining to some extent, by means of 

 the microscope, in what portions of the 

 plant the various constituents are con- 

 tained. At the same time plant physiol- 

 ogists have been endeavoring to deter- 

 mine the elements necessary as food for 

 the plant and their influence in the 

 formation and transformation of food and 

 tissues. 



At the outset of the discussion of this 

 subject, we must understand that there 

 are two great schools of plant physiolog- 

 ists, which are distinguished from each 

 other, principally by their methods of 

 work. The one originated by Sachs 

 when his text-book was written, and his 

 views are to-day quite closely followed 

 by nearly all writers of text-books em- 

 bracing this subject. In this school there 

 is much speculation and conjecture; there 

 are many who express the hope of being 

 able to trace the courses of the changes 

 connected with "plant metabolism" in 

 such a manner as to prove by actual 

 weight and measurement the great prin- 

 ciple of the conservation of energy. We 

 find quite a number of authors of great 

 abilities who have tried to give some hy- 

 potheses which might explain the exact 

 nature of the changes by which the 

 rhythm, of destructive and constructive 

 metabolism is kept up in the living pro- 



