INTRODUCTION 205 



study of cultivated plants, and this is the early literature on medicine. 

 Prominent are the books of the physician Can Cun-kin i it S or 

 Can Ki K 18, who is supposed to have lived under the Later Han at 

 the end of the second century A.D. A goodly number of cultivated plants 

 is mentioned in his book Kin kwei yil han yao Ho fail lun & S 3i 3& 

 3c ~}3 Ift or abbreviated Kin kwei yao lio. 1 This is a very interesting 

 hand-book of dietetics giving detailed rules as to the avoidance of 

 certain foods at certain times or in certain combinations, poisonous 

 effects of articles of diet, and prescriptions to counteract this poison. 

 Neither this nor any other medical writer gives descriptions of plants 

 or notes regarding their introduction; they are simply enumerated in 

 the text of the prescriptions. But it is readily seen that, if such a work 

 can be exactly dated, it has a chronological value in determining whether 

 a given plant was known at that period. Thus Can Ki mentions, of 

 plants that interest us in this investigation, the walnut, the pome- 

 granate, the coriander, and Allium scorodoprasum (hu swan). Unfortu- 

 nately, however, we do not know that we possess his work in its 

 original shape, and Chinese scholars admit that it has suffered from inter- 

 polations which it is no longer possible to unravel. The data of such 

 a work must be utilized with care whenever points of chronology are 

 emphasized. It was rather tempting to add to the original prescrip- 

 tions of Can Ki, and there is no doubt that the subsequent editions 

 have blended primeval text with later comments. The earliest com- 

 mentary is by Wan Su-ho : $t %R of the Tsin. Now, if we note that 

 the plants in question are otherwise not mentioned under the Han, but 

 in other books are recorded only several centuries later, we can hardly 

 refrain from entertaining serious doubts as to Can Ki's acquaintance 

 with them. A critical bibliographical study of early Chinese medical 

 literature is an earnest desideratum. 



A. DE CANDOLLE'S monumental work on the "Origin of Cultivated 

 Plants " is still the only comprehensive book on this subject that we 

 have. It was a masterpiece for his time, and still merits being made 

 the basis and starting-point for any investigation of this kind. De Can- 

 dolle possessed a really critical and historical spirit, which cannot be 

 said of other botanists who tried to follow him on the path of his- 

 torical research; and the history of many cultivated plants has been 

 outlined by him perfectly well and exactly. Of many others, our con- 

 ceptions are now somewhat different. Above all, it must be said that 



1 Reprinted in the Yii tswan $ tsun kin kien of 1739 (WYLIE, Notes on Chinese 

 Literature, p. 101). A good edition of this and the other works of the same author on 

 the basis of a Sung edition is contained in the medical Ts'un-Su, the / t'uti en mo 

 ts'uan Su, published by the Ce-kian Su ku. 



