TUBERCULAR DIATHESIS : ITS TREATMENT. 



cold and damp, long-continued mental depression, &c. The 

 treatment of the Tubercular diathesis (as this state of consti- 

 tution is termed) must be directed to the invigoration of the 

 system by good food, active exercise, pure air, warm clothing, 

 and cheerful occupation; and by the due employment of 

 these means, at a sufficiently early period, many valuable lives 

 may be saved which would have otherwise fallen a sacrifice. 

 The value of cod-liver oil in the treatment of this disease, 

 which is now a well-established fact, seems to depend upon 

 the facility with which it is assimilated as a nutritive material. 

 It is a remarkable fact that the inhabitants of Iceland, the 

 greater part of whom live under conditions that might be 

 expected to favour the development of tubercular disease, are 

 singularly free from it; and the source of this exemption 

 seems to consist in the very oleaginous nature of their diet. 

 Consumption presents itself among the inhabitants of all 

 climates ; and the value of change to a patient who is 

 affected with this malady, chiefly depends upon the oppor- 

 tunity which it affords him for abundant exercise in the open 

 air, without injurious exposure to cold or damp. 



387. From the foregoing facts it is evident, that the opera- 

 tions of Nutrition are due, on the one hand, to the indepen- 

 dent properties of the several Tissues, which draw from the 

 blood the materials of their continued growth and renewal ; 

 and, on the other, to the properties of the Blood, which 

 supplies them with these materials. The blood, left to itself, 

 could form no tissue more complex than a mere fibrous net- 

 work : whilst, conversely, the various tissues of the body 

 could not draw their nourishment directly from the products 

 of digestion, and are consequently dependent upon the blood 

 for their supply. We may illustrate the relation between the 

 three states, that of aliment, blood, and organized tissue, 

 by comparing them with the three principal states which 

 Cotton passes through in the progress of its manufacture, 

 namely, the raw cotton, spun-yarn, and woven fabric. The 

 spun-yarn could not of itself assume that particular arrange- 

 ment which is given to it by the loom ; and the loom could 

 make nothing of the raw cotton, until it has been spun into 

 yarn. 



388. It is also evident, that the blood-vessels have no other 

 purpose in the act of Nutrition, than to convey the circulating 



