LANDMARKS OF BOTANICAL HISTORY GREENE 49 



ENSIS is mentioned by Theophrastus as one of the worthiest among 

 them, because as if ignoring the common beliefs about magical 

 effects he gave himself to the investigation of the properties of 

 plants. He seems to have been the original proponent of the 

 doctrine that the good or bad effects of a medicine may depend 

 upon the temperament of the individual patient; a proposition 

 which has met with some acceptance, at least outside the pro- 

 fession, if one may judge by its having been long since crystallized 

 into a proverb, that what is medicine to one, may be poison to 

 another. The idea is revolutionary, though without yet having 

 brought about much of a revolution. To this same Thrasyas is 

 ascribed the compounding of that vegetable poison, so frequently 

 in use with the ancients, which never failed to bring a speedy and 

 absolutely painless death. 1 Theophrastus devotes two chapters 

 to an account of the pharmacological researches of this Thrasyas, 

 and those o his eminently successful disciple Alexius, and of those of 

 a third of the same school of intelligent and really scientific rhizo- 

 tomi, Eudemus of Chios. One and another of these men, living at 

 periods so remote as barely to fall short of being prehistoric, tested 

 in their own persons the adaptability of the human system to the 

 harmless use of drastic and poisonous vegetable substances. Be- 

 ginning with small doses and increasing them gradually, it was 

 ascertained that one might after a time consume without bad 

 results such a quantity of hellebore, for example, as under ordinary 

 conditions might have proven fatal. Using at first earthen pots 

 and pans in the probing of questions about possible or probable 

 antidotes to certain poisons, they would proceed, under the light 

 gained by such experiments, to the using of their own stomachs as 

 the crucibles. 2 And the reports of these instructive and daring 

 experiments, together with the names of the men who made them, 

 were either written and subscribed to at the time or else handed 

 down by tradition to the time of Theophrastus who gave them per- 

 manent record. 



Among the earlier rhizotomi there was a famous one named 

 CLEIDEMUS, who wrote upon the subject of electrical storms so as 

 to have been quoted by Aristotle in his Meteorology. 3 He also in- 

 vestigated diseases of plants, especially of the fig-tree, olive-tree, and 

 vine. Cleidemus is therefore the earliest of vegetable pathologists. 

 And what may be more interestingly significant is this, that Theo- 



1 Theophrastus, Hist. Plant., Book ix, ch. 17. 



2 Ibid., ch.'iS. 



3 Aristotle, Meteor., Book i, ch. 2. 



