August 30, 1912] 



SCIENCE 



269 



opment of organic chemistry during the 

 last twenty years, and especially along phy- 

 tochemical lines, that in the not distant 

 future all of the more important plant 

 compounds will have been products of the 

 laboratory. That there is ground for such 

 a statement is borne out by what has al- 

 ready been done. The investigations of 

 Loew, Butleroff, Kiliani, Emil Fischer and 

 Wohl on the carbohydrates are so familiar 

 to every one that it is only necessary to 

 briefly refer to them at this time. The 

 aldehyde condensation reaction by Loew 

 and Butleroff, the building up of the sugars 

 by Kiliani and the down-building by "Wohl 

 make the synthesis of the hexoses an estab- 

 lished fact and the synthesis of the bioses 

 at least a possibility in the near future. 



The briefest phyto-synthetie review 

 would be incomplete without referring to 

 the most recent work of Emil Fischer and 

 his pupils on the so-called polypeptides. 

 Here is a group of complex substances be- 

 longing to the albumins of both the plant 

 and the animal world, a group of com- 

 pounds whose synthesis has, until recently, 

 been regarded by many as beyond human 

 possibility. Nevertheless, Fischer has built 

 up the complex polypeptides until the arti- 

 ficial molecules are equal in size to the 

 albumins themselves, leaving the synthesis 

 of these complex chemical substances no 

 longer in the list of vain possibilities. 



Of scarcely less importance in the phyto- 

 chemical world than the carbohydrates, the 

 alkaloids and the albumins, are the resins 

 and terpenes. Wallach has presented a 

 satisfactory constitutional formula for 

 pinene, but the resins are still classed with 

 substances of unknown constitution. Not- 

 withstanding the fact that less is known 

 concerning the chemical nature of the resins 

 than perhaps any other group of organic 

 compounds, they are doubtless the oldest 

 organic compounds known to man. They 



played an Important part in the chemical 

 industries in the early history of mankind. 

 They were used in almost every phase of 

 early human life, as lacs, varnishes, balsams, 

 perfumes, pomades and in the art of em- 

 balming. They were described by the early 

 alchemists as substances insoluble in water, 

 generally soluble in alcohol, and for the most 

 part non-crystallizable. They are the re- 

 sult of secretive plant fluids, exuding from 

 plants and hardening in the air. They 

 could not be separated into their constitu- 

 ents by any means known to the early 

 chemists, and were therefore regarded as 

 single substances. As a rule, however, they 

 are mixtures of two or more complex sub- 

 stances, a gum and some volatile oil ©r 

 terpene. They were known as gum resins 

 or natural balsams and with the terpenes 

 as oleoresins. As a result of their non- 

 crystalline nature they were generally ex- 

 cluded from the list of substances worthy 

 of investigation. 



That there is a close chemical relation- 

 ship between the resins and the terpenes, 

 there can be no doubt, notwithstanding the 

 fact that there is comparatively little ex- 

 perimental evidence to prove the assertion. 

 One of the reasons usually given for the 

 assumption is based on the fact that the 

 resins and terpenes generally occur to- 

 gether in plants. This is by no means 

 important evidence, for it frequently hap- 

 pens that entirely different groups of or- 

 ganic compoimds are intimately associated 

 with each other in both plant and animal 

 life. 



Notwithstanding the fact that consider- 

 able general industrial work has been done 

 on the resins, especially those of the pine 

 family, yet no one has been able to deter- 

 mine with certainty the molecular constitu- 

 tion of any of them, not even of abietie 

 acid, the most common and the most impor- 

 tant of all of the resin acids. Not only are 



