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 are 

 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 properbies 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 possesses a remedy 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, because 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 dubium quin Emetica in terris zonne fervidae subjects effectus 

 producent multo 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 



