28 BOTANICON SINICUM. 
and the Pen ts‘ao (see note 6), to assemble in the eapital.—In 
the biography of ## 3% Lou Hou (Ts‘ien Han shu, 92) it is said 
that, when he was yet but a boy, he knew by heart the ee, 
J king (treatise on medicine), the Pen ts‘ao and several thousands i 
of medical prescriptions. Thus there can be no doubt that at that — 
time there existed a Pen ts‘ao. 3 
Ja Shi tsi (an author of the Tang period, 7th century), and | 
before him the 4 2%, Tsi lu, a work of the Liang dynasty (6th — 
century), speak of the Shen nung pen ts‘ao in 3 books; suggesting — 
that it was probably committed to writing during the Han — 
dynasty, for there occur in the book names of places in China — 
referring to the time of the After Han (25—221 A. D.). Ace — 
cording to these authorities Chang Ki or Hua Tv? may be the | 
authors of it. But Chang Yi si (who quotes the above state- — 
ments) does not agree with this opinion. He admits an early 
existence of the Pen ts‘ao king and adduces the Huai nan tsz’ 
(2nd century B. C.), which records that Emperor Shen nung in | 
the space of one day tasted the plants and experimented on their — 
eficacy. He found among them 70 to be poisonous, This was — 
the beginning of medical urt in China. ; q 
Chang Yii si continues: In remote times, when the art of © 
writing was not yet known, science was transmitted from gene- 
ration to generation by oral tradition, and what was called Pen 4 
ts‘ao then was not a written book. From the period of the Han | 
dynasties (B. C, 202—A. D. 221) medical art began to develop. — 
Chang Ki and Hua T‘o’ largely contributed to the diffusion and — 
completion of medical knowledge, commented an previous writings, — 
and added new information, arranging the whole into a system. — 
This was probably the time when the Materia medica of Shen 
nung first appeared as a written treatise. 
Kou Tsung shi (about 1115 A. D.) says: In the History of the 
Han dynasty it is stated that it is not certain who first compiled — 
the Pen ts‘ao. The Shi pen (written befure the Han period) and © 
the Huai nan tsz’ duly record that Shen nung tasted plants and 
examined their medical virtues, but they do not speak of a Pen 
