different from the great alterations to which other beings are exposed, 

 from the mere change of climate. Man is every where indigenous, and 

 exists in all climates; while the plants and animals of the equator lan- 

 guish and die when conveyed to the polar regions. From the flexibility 

 of his nature, man enjoys the power of adapting himself to the most op- 

 posite situations, of establishing, between them and himself, relations 

 compatible with the preservation of life. Nevertheless, it is not without 

 difficulty that man undergoes these changes, and accustoms himself to 

 new impressions. The periodical return of the season determines that 

 of certain derangements, to which the animal oeconomy is subject. The 

 same diseases manifest themselves under the influence of the same tem- 

 perature, and to use an ingenious comparison, resemble those birds of 

 passage which visit us ut stated seasons of the year. Thus hemorrhages 

 and eruptive affections come on with the return of the spring, summer 

 comes attended by bilious fevers, autumn brings on a return of dysen- 

 teric affections, and winter abounds in inflammation of the lungs and 

 other parts. The influence of climate on the human body, does not show 

 itself merely in occasioning epidemic diseases, the consideration of which 

 led to the establishing what physicians call medical constitutions. This in- 

 fluence operates on man in health, as well as in sickness; and to say 

 nothing of the alterations which our moral nature experiences from the 

 tendency of love, rendered more impetuous with the return of spring, or 

 of melancholy, to which nervous people are often subject towards the 

 end of autumn, when the trees are shedding their leaves, the increase of 

 growth is particularly remarkable at the time of the first growth of 

 plants, as was observed again and again, by a friend of mine, physician 

 to a large seminary. 



Seventhly. Sensibility is greater in women and children ; their nerves* 

 are likewise larger and softer, in proportion to the other parts of the 

 body. In general, the principle of sensibility seems to decrease, in pro- 

 portion as it has contributed to the developement of the acts of life ; and 

 the power of being impressed by external objects, diminishes gradually 

 with age, so that there is a period of decrepid old age, at which death ap- 

 pears a necessary consequence of the complete exhaustion of that princi- 

 ple. In short, as I have said in describing the progress of death, at its 

 approach, sensibility shows increase of activity and liveliness, as if its 

 quantity required to be completely exhausted, before the termination of 

 existence, or as if the organs made a last effort to cling to life. 



The developement of the cellular and adipose substance, diminishes 

 the energy of sensibility, the extremities of the nerves being more cover- 

 ed, and therefore not so immediately applied to the objects, the impres- 

 sions which when felt, are more obscure. The fat operates on the nerves, 

 as wool would do on vibrating chords, if wrapped round them, to fix 

 them, to prevent their quiverings, and stop their vibrations. 



Very nervous women are very thin ; persons of much sensibility have 

 seldom much fleshiness. Swine, in which the nerves are covered by a 

 thick layer of fat, are the most insensible of all animals. The suscepti- 

 bility of the nerves may be diminished, and their sensibility blunted by 

 pressure. The application of a bandage firmly rolled round the body and 

 limbs of an hysterical woman, will diminish the violence of her fits. In 



* Their voluntary nerves; 



