During perspiration the blood is deprived, in proportion as the diaphoresis continues, not only of the liquor-sanguinis, but of the chloride of sodium which it holds in solution. Though to a certain extent perspiration is an act of nature necessary for the continuance of health, yet, if it goes beyond a point which is consistent with an equalisation of the several secretions, the individual experiences a diminution or loss of power, and nervous exhaustion or irritability is the result. In natural diaphoresis the only way in which the system can recuperate itself is by quenching the thirst; for free perspiration is generally or almost invariably succeeded by a corresponding thirst, varying in intensity according to the peculiar idiosyncrasy of the individual. Thin people do not perspire so copiously as those who are more stoutly built, therefore they do not lose so much and neither do they require so much fluid. Their blood, by reason of its retaining its liquor-sanguinis and its chloride of sodium, does not require salt as an aliment so freely as those who, owing to their profuse perspiration, are in constant want of it. Stout people, or those who have a superabundance of adipose tissue (for I must observe there is a great difference between stoutness and obesity, though in common parlance the two words are synonymous), require salt in a greater degree than thin people. Well-developed muscles covering a well-made frame, accompanied by a proper and due proportion of fat, constitute stoutness of a healthy standard; but small muscles covered with an overdue amount of fat, with an abdomen distended to an offensive size (which is so frequently seen), seem, in my opinion, to determine a habit of a Vitellian obesity, if I may so apply the name of that Roman epicure.