174 THE JOURNAL OF BOTANY 



te be caused, not by Vanilla itself , but by the use of Oil of Cashew 

 to improve the colour etc. of the pods. This Cashew oil is the 

 irritant. 



Again, a considerable number of the rarer and more beautiful 

 woods, such as are used for fine furniture, pianos, etc., and in the 

 making of umbrella-handles and walking-sticks, or the particularly 

 hard woods used for shuttles, are well known to have an irritating 

 effect on the skin of the workers ; and where much turning is involved, 

 the fine dust created may affect the eyes and nose. Thus Satin- 

 wood (both the East and West Indian varieties), produces a rash 

 which closely resembles Primula poisoning. The arms and face are 

 affected, and it is generally accompanied by head-ache. The infiamma- 

 tion is apt to be acute and erysipeloid : the eyes may be completely 

 closed up, and the attack terminates by the desquamation of the 

 affected skin. It has been demonstrated that the poisonous sub- 

 stance is an alkaloid, which has been called chloroxt/lonine. The 

 following are some of the woods described as causing irritation : — 

 Satin-wood {Chloroxylon Swieteiiia, £ackhousia cifriodora, 

 Xanthoxyluni carihwum); Teak {Tectona (jrandis); various Ebonies 

 {Diospyros CJdoroxylori, D. Eberium, etc.); Rosewood {Dalberyia 

 latifolia) ; Olive- Wood {Elceodendron ausirale, E. orientale) ; 

 Box {Buxus sempervirens) ; Coco-wood (Liya vera) ; Partridge- 

 wood (Andira i iter mis). 



These industrial cases are important because of the questions they 

 involve of compensation for industrial disease, and are often extremely 

 puzzling to a practitioner who is new to the work [cf. lieport of the 

 Departmental Commission on Compensation for Industrial Diseases, 

 1907, § 887. Also, Kobinson, Annual Report of II.R.C. Inspector 

 of Factories, l^Ol]. 



The essential botanical interest of the subject seems to centre in 

 the fact that the poisonous substances are apparently normal pro- 

 ducts of metabolism in the plants concerned, and that the toxic effect 

 produced may only be noticed by accident of some economic associa- 

 tion with the plants, by which a large number of persons are brought 

 into contact with them or their products. This casual relationhip 

 perhaps accounts for the seemingly irregular and sporadic occurrence 

 of poisonous members of a genus : the reason for this being that only 

 certain members are of economic value, and consequently handled in 

 large quantities. It would be entering too far into debatable ground 

 even to attempt to discuss the possible significance of these poisons in 

 the ordinary metabohsm of the plant producing them. The sub- 

 stances themselves are so varied, including organic acids {e.g. the 

 cell-sap of the leaves of Laportea gigas contains '224 % free acetic 

 acid), alkaloids, phenols, glucosides, terpenes, etc. Their functions 

 also are in many cases conjectural ; suggestions ranging from osmotic 

 substances or plastic materials to solvents, neutralizing agents, and 

 the protection of the plant from attack by animals or insects. 



Questions as to the secondary biological utilization of such com- 

 pounds by the plant can only be answered by accurate observations 

 on the attack and repulsion of animals or insects by the ])lant in 

 question. To take a simple illustration, the ''stinging hairs" of the 



