- 206 NATURE AND LIFE. 
condition of the botanical and zoological knowledge of their 
day, became the guide of experiments in healing, under the 
influence of which the first books relating to substances 
having medicinal qualities were written, among others the 
treatises of Scribonius, Largus, and of Dioscorides. That 
of Scribonius bears the title, ‘‘ On the Composition of Medi- 
cines.” It is dedicated to a freedman of the Emperor 
Claudius. The author had collected its materials in the 
different campaigns in which he had been attached as army 
physician to the Roman legions. Dioscorides also, who 
lived under Nero, was connected with the army in the 
capacity of a doctor, and collected in the countries he 
traversed a great number of substances taken from the 
three natural kingdoms. Returning to Rome, he made a 
selection of those which seemed to him to possess some 
efficacy in medicine, and described them in the Greek 
language in an important book, which gives us the most 
exact idea of the materia medica of the ancients, and which 
continued to bea classic until the sixteenth century. This 
book had the same vogue as those of Aristotle had; but 
we Shall find that this kind of submissiveness to an ancient 
master has not stood in the way of progress. 
Galen, the most learned and systematic among ancient 
physicians, gives a new form and impulse to therapeutics. 
Coming a little later than Dioscorides, he aimed to point 
out the best use that could be made of the weapons col- 
lected in the arsenal of pharmacy by the latter. The doc- 
tor of Pergamus had faith in the need of prescribing many 
remedies as firm as the conviction of Hippocrates that Na- 
ture should be permitted to act almost by herself in dis- 
eases. He substituted for the expectant methods the use 
of an abundance of drugs, and suggested the invention of 
those complicated mixtures known under the name of elec- 
tuaries. Galenism is the origin of polypharmacy. It was 
supposed, under the control of those notions to which this 

