INTRODUCTION. 
xliii 
excluded because of their inertness. In tropical countries, where a fervid 
sun, a humid air, and a teeming soil give extraordinary energy to vegetable 
life, the natives of those regions often recognise the existence of potent 
herbs unknown to the European practitioner. No doubt such virtues aro 
often as fabulous and imaginary as those of indigenous plants long since 
rejected by the sagacity of European practice. But we are not altogether 
to despise the experience of nations less advanced in knowledge than our- 
selves, or to suppose, because they may ascribe imaginary virtues to some 
of their officinal substances, as has been abundantly done by ourselves in 
former days, that therefore the remedial properties of the plants are not 
worthy of serious investigation or that their medical knowledge is beneath 
our notice because they are unacquainted with the terms of modern science. 
It is not much above 20 years since an English officer in India was cured of 
gonorrhoea by his native servant, after the skill of regular European practi- 
tioners had been exhausted. The remedy employed was Cubebs, the import- 
ance of which was previously unknown, and the rationale of whose action is 
to this day beyond the discovery of physiologists. It is of undoubted value 
in urethral catarrh : and who shall say that there are not hundreds of equally 
powerful remedies still remaining to be discovered. * * * and it 
must be sufficiently apparent to all unprejudiced minds, that the resources 
of the vegetable kingdom, far from being exhausted, have hardly yet been 
called into existence. It is presumptuous for the theorist to assert that he 
already poss sees a romedy for all the maladies that flesh is heir to ; it is 
mere idleness in the routine practitioner, carried away by the attraction of 
spacious generalities, to fancy that one tonic is as good as another tonic, or 
one purgative as another purgative. In reality the true cause of the differ- 
ent actions of medicines upon the human body is admitted by the highest 
authorities to be wholly unknown ; and surely this is in itself the best of all 
reasons why we should not assume that we already possess against disease 
all the remedies which nature affords ; on the contrary it should stimulate us 
to reiterated enquiries into the peculiar action of new remedial agents. * * 
* “And they (i.e., European practitioners) find the medicines which are 
powerful in Europe, comparatively inactive in other climates. The heat of a 
country, its humidity, particular localities, food, and the social habits of a 
people will predispose them to varieties of disease for which the drugs of 
Europe offer no sufficient remedy, and will render that which is relied upon 
in one country unworthy of dependence in another. Thus the Cinchona bark 
of ,Peru, important as it is in Europe, is, we are told, rejected by the people 
among whom it grows, becauso it is found too stimulating and heating for 
their excitable constitutions. And speaking of Ipecacuanha, Dr. Von Maritus, 
who so carefully examined practically the Materia Medica of Brazil, asserts 
“ nullumest dubiura quin Emetics in terris zonne fervidae subjects effectus 
producent mnlto magis salutares quam in regionibus frigidioribus.” 
“ This last observation seems to indicate, that if emetic plants are so 
much more common in hot than cold countries, it is because there is so much 
greater a necessity for them. The late Mr. Burnett, and many other persons, 
have asserted that every country spontaneously furnishes remedies for those 
maladies which the people of the soil are naturally subject to, and that the 
