by him, at least two years before the appearance of Dr. Thomas's work.[60] After explaining the doctrine of the temperaments, as taught by the ancients, and showing that it is founded on the exploded hypothesis of humoralism, Dr. C. goes on to show, that it is the _solids_ of the body which make man what he is; that they form the _fluids_, and give them their character; that they are, in short, the _cause_, and the fluids the _effect_. "The difference," says Dr. C., "between individuals, or rather classes, of the human family, which temperament is made to designate, appears to depend on two causes; diversity of organization in parts or the whole of the bodies of different persons, giving rise to a corresponding diversity in the vital properties; and difference of size and vigor in certain ruling organs of the system. The existence and influence of the former of these causes are in the highest degree probable; those of the latter certain. The one is susceptible of strong support, the other of proof that may be termed positive. By 'organization' is here meant, the minute interior or radical structure of the tissues which compose the human body. That diversity in this creates a diversity in the vital properties, and that again a diversity in character, cannot I think be doubted. Whether the difference of organization here referred to, consists in different proportions of the element of living matter that form the tissues, united in the same way, or in their different modes of arrangement and union, or both, or whether it may not arise in part from different proportions of the simpler tissues entering into the formation of the more compound organs, is not known. Minute anatomy has not yet attained a degree of perfection competent to settle a point of such subtility."