435 



Of all the causes that can modify the nature of man, and which will 

 even change completely the nature of his native dispositions, there is 

 none more powerful than the long continued action of air, water, and re- 

 sidence, as the father of medicine has said. Climate, in fact, exerts upon 

 the temperament the most marked influence. Thus the bilious tem- 

 perament is that of the greater part of the inhabitants of southern 

 countries; the sanguine that of the north; the lymphatic constitution 

 reigns, on the contrary, in cold and moist countries, like Holland. We 

 have seen in what manner the athletic, melancholic, and nervous tern- 

 temperament grows out of our habits of life : let us now endeavour to 

 appreciate the power of climate over the constitution of the greater part 

 of mankind. 



It is known, that the influence of heat, in the production of bilious 

 diseases, is such, that after having been extremely prevalent, during the 

 summer, they disappear, or at least become much less frequent in the 

 autumn. A notable increase of perspiration never takes place, without 

 a proportional diminution in the quantity of the liquids with which the 

 alimentary surfaces are moistened. Now, when the gastric juice is less 

 abundant, the bile, being mixed with a smaller quantity of serosities, ir- 

 ritates more the intestinal surfaces; the digestive powers languish, and 

 there is an approaching disposition to meningo-gastric fevers. The 

 same influences, continued during the whole year in hot countries, must 

 necessarily increase, with the activity of the biliary system, its power 

 over the other parts of the economy, and thus establish a predominance 

 of the bilious constitution, through both health and disease. 



As for the sanguine temperament, so generally met with among north- 

 ern nations, it is the necessary consequence of the continual and very en- 

 ergetic re-action of the powers of circulation, against the effects of exter- 

 nal cold. It is only by the constant activity of the heart and vessels, that 

 calorification can be effected with the necessary vigour. Now, the effects 

 of this redoubled action are the same to the organs of circulation, as to 

 the muscles under the influence of volition : in both, exertion increases 

 the power of the organs exerted. The diseases of the nations of the 

 north, analagous to their temperament, have, for the most part, their seat 

 in the system of sanguineous vessels : their character is eminently inflam- 

 matory. 



Lastly, the lymphatic state of nations, living under a moist climate, is 

 nothing more surprising than the aqueous nature of plants, and small 

 density of the wood, in trees growing under the influence of a foggy air. 

 Animal bodies, like plants, absorb by their surfaces, and become gorged 

 with humours, the excess of which always produces a remarkable slack- 

 ening of activity in the organic motions. 



The temperament of which the character is the predominance of one 

 organ or system of organs, departs from that ideal state, where all the 

 powers are reciprocally balanced, so as to exhibit in the living economy a 

 perfect equilibrium. This state, which has perhaps never been found 

 but in the imaginations of physiologists and which was called by the an- 

 cients the temperate temperament, temperamentum temperatum^ being' 

 taken as the type of health, it follows that this temperament is already a 

 step made towards disease. Yet the action of the predominant system is 

 not in such excess as to destroy all equilibrium, and impede the action of 

 life; but let the constitutional dispositions be much increased, the dis- 

 ease is begun, and this transition takes place in the conversion of the 



