596 OF NUTRITION. 



seem to have their origin in a disordered state of the Blood, rather than in the 

 solid tissues affected, we find a remarkable tendency to the repetition of the 

 patches, on the two sides of the body, or on the corresponding parts of the 

 limbs; and this we must attribute to the peculiar attraction subsisting between 

 the solid tissues of those parts, and the morbid matter circulating through 

 them. So in those chronic forms of Gout and Rheumatism, which modify 

 the nutrition of the joints, producing a deposit of "chalk stones," or perma- 

 nent distortion and stiffening from an alteration of the tissues, of the joint, we 

 almost invariably find the corresponding joints of the two sides affected. 

 The chief exceptions to the general principle, that the presence of morbid or 

 extraneous matters in the blood affects all parts alike, are found to occur 

 where there is much febrile disturbance, or where local causes produce a 

 peculiar tendency to disorder of a single part. The nearer the approach 

 presented by the mofbid process, in point of rate and character, to the ordi- 

 nary nutritive operations of the part, the more does it tend to approach these, 

 in the symmetry with which it developes itself.* 



2. Varying Activity of the Nutritive Processes. Reparalive Operations. 



786. Without any change in the character of the Nutritive processes, there 

 may be considerable variations in their degree of activity ; and this, either as 

 regards the entire organism, or individual parts, though most commonly the 

 latter. These variations maybe so considerable as to constitute Disease; 

 though there are some which take place as part of the regular series of Phy- 

 siological phenomena. Thus, the Nutritive processes should have a degree 

 of activity more than sufficient to supply the Waste of the body during the 

 whole period of infancy, childhood and adolescence, until, in fact, its full 

 dimensions are obtained ; whilst, on the other hand, they are usually less 

 rapid than the disintegrating processes in old age, so that the bulk of the body 

 diminishes. Now as the Waste of the body, so far from being more rapid in 

 old age than in childhood, is much less so, it follows that the difference in 

 the activity of the Nutritive processes in these two states must be very con- 

 siderable ; and this is manifested, not only in the greater demand for food 

 which exists in the child (relatively to the bulk of its body), but also in the 

 greater quickness and facility with which injuries are repaired. Local varia- 

 tions may also occur, as part of the regular train of vital actions in the adult; 

 thus we perceive an enormous increase in the amount of tissue contained in 

 the Uterus and Mammary glands during pregnancy, and a decrease in the 

 bulk of the Thymus gland after the period of infancy. Now in these cases 

 we see, that increased Nutrition is invariably connected with increased Func- 

 tional activity; and diminished nutrition with diminished functional activity: 

 and this we shall find to be the constant rule, in regard also to those variations 

 which must be considered as abnormal. 



787. Increased Nutrition, or Hypertrophy, is never known to affect the 

 whole body, to a degree sufficient to constitute disease. It cannot be pro- 

 duced as a consequence of the ingestion of an undue supply of food : for this 

 does not increase the formative activity of the tissues, but merely renders the 

 blood richer in nutritive materials; a part of which the excreting organs are 

 called on to be continually removing, without its being rendered subservient to 

 the wants of the body ( 819); whilst another part may be employed in the 

 nutrition of one particular tissue, the Adipose, which has a tendency to in- 

 crease with the superfluity of non-azotized food, provided that the requi- 



* See Dr. W. Budd's valuable paper on the "Symmetry of Disease," in vol. xxv. of the 

 Medico-Chirurgical Transactions. 



