sidered alcohol at length, it is not necessary to devote much space to the other narcotics, opium among the rest. The two processes of evolution—i.e. against alcohol and opium—must have proceeded on very similar lines, except in so far that immunity against opium was probably much more easily and quickly achieved than immunity against alcohol, for the reasons that a much smaller divergence from the ancestral type apparently suffices to protect against the latter, and because poisonous preparations of opium are much more easily manufactured than like preparations of alcohol—as is natural since opium is a "toxin," a substance that protects the organism producing it from other organisms to which it is liable to become a prey. It must therefore have been from the time it was first used as an intoxicant, the cause of a much severer process of selection than was alcohol when first used.
The Greeks of the time of Hippocrates were acquainted with the medicinal use of opium,[1] and early imparted their knowledge to the Arabs,[2] who in turn introduced the poppy with the knowledge of its medicinal properties to India and China,[3] to the latter country later than to the former, but yet as early as the eighth century. But not till very long afterwards, not till five hundred years or more had elapsed, was the unfortunate discovery made that it might be used like alcohol to produce pleasurable sensations. For some hundreds of years its use as a narcotic has been prevalent in certain parts of India, whence at the beginning of the last century the Chinese acquired the knowledge and the habit of using it, as a consequence of which the famous import trade with India sprang up. The Burmese have had far less experience of the drug, indeed they have used it extensively only within the memory of living
