1901.] Spurge (Euphorbia hiberna, L.) on Salmonoid Fishes. 49 



branches of science, I have been obliged to seek assistance from special- 

 ists in the different departments, and I wish to acknowledge my 

 indebtedness. Mr. Robertson, Lecturer in Botany at St. Andrews 

 University, has aided me with the botanical literature on the subject, 

 and the keen interest he took in the progress of the research was dis- 

 played in many valuable suggestions. To Dr. Fraser Harris, Lecturer 

 in Physiology at the same University, I am even more indebted, since 

 he freely gave his advice as to the best methods of conducting the 

 physiological experiments which the research necessitated, and very 

 kindly revised the manuscript. My indebtedness to the chemists will 

 be displayed later, but I must here thank Professor Mcintosh, F.E.S., 

 for his kindly encouragement and the facilities he gave me for my 

 work at the Gatty Marine Laboratory. 



Description of the Plant and its Chemical Composition. 



Euphorbia hiberna, L., or the Irish Spurge, is a member of the large 

 order Euphorbiacea?, which gives to medicine such well-known drugs 

 and poisons as croton oil, cascarilla, and castor oil. It is a hardy 

 perennial weed, growing to the height of about 2 feet, with dull 

 greenish leaves and inflorescences of an orange-yellow colour. Its 

 area of distribution is mostly on the Continent in France, Switzerland, 

 and Italy, but it is also found in the South of England and South of 

 Ireland. Its reputation is well known, for in all reference works, 

 botanical or pharmacological, where it is mentioned, one finds the 

 statement that it is used in Ireland to poison fishes. 



The fresh plant is almost odourless, but the expressed juice from the 

 laticif erous vessels and the emulsion formed in water have a very faint,, 

 pungent, and slightly aromatic odour. In this respect it differs some- 

 what from the officinal Euphorbia (E. resinifera, Berg), a native of 

 Northern Africa, which is said to have a powerfully irritating acrid 

 odour. In the latter, according to Fliickiger,* who examined the dried 

 exported drug, this acridity is due to amorphous indifferent resin. It 

 is probable that the fresh extract — with which alone we are concerned 

 in E. hiberna — would differ somewhat from the analysis given by him. 

 Thus he found no volatile oil on distilling the drug with water, 

 whereas a small quantity of some volatile substance was obtained from 

 E. hiberna by the same means. Again, he declares that no emulsion is 

 formed in water by the drug obtained from E. resinifera. On the other 

 hand, an emulsion characterises the fresh aqueous extract of E. hiberna. 

 Fliickiger's analysis would seem, therefore, to apply to the oxidation- 

 products of the original substances in E. resinifera, and is hardly com- 

 parable with that of E. hiberna to be presently given. 



In one respect E. resinifera differs essentially from E. hiberna : in the 



* ' Pkarrnacognosie des Pflanzenreiches,' p. 194 ; ' Pharmacographia,' p 504. 



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