46-i OF NUTRITION. 



379. But although Tubercular matter may be slowly and insidiously de- 

 posited, by a kind of degradation of the ordinary Nutritive process, yet it 

 cannot be doubted that Inflammation has a great tendency to favor it; so 

 that a larger quantity may be produced in the lungs, after a pneumonia has 

 existed for a day or two, than it would have required years to generate in 

 the previous mode. But the character of the deposit still remains the 

 same; and its relation to the plastic element of the blood is shown by the in- 

 teresting fact, of no u ID frequent occurrence, that in a Pneumonia affecting 

 a tuberculous subject, plastic lymph is often thrown out in one part whilst 

 tubercular matter is deposited in another. Now Inflammation, producing a 

 rapid deposition of tubercular matter, is peculiarly liable to arise in organs 

 which have been previously affected with chronic tubercular deposits by an 

 impairment of the process of textural Nutrition ; for these deposits, acting 

 like foreign bodies, may of themselves become sources of irritation ; and the 

 perversion of the structure and functions of the part renders it peculiarly 

 susceptible of the influence of external morbific causes. 



380. We frequently meet with abnormal growths of a Fatty, Cartilaginous, 

 Fibrous, or even Bony structure; which result from the development of 

 these tissues in unusual situations, and appear to originate in some perverted 

 action of the parts themselves ( 355, 376). But there is another remark- 

 able form of disordered Nutrition, which is concerned in producing what 

 have been termed heterologous growths that is, masses of tissue that differ 

 in character from any which is normally present in the body. Most of these 

 are included under the general designation of Cancerous or Fungous struc- 

 tures; and it has been shown by Miiller and succeeding inquirers, that the 

 new growth consists of a mass of cells; which like the Vegetable Fungi, de- 

 velop themselves with great rapidity; and which destroy the surrounding 

 tissues by their pressure, as well as by abstracting from the Blood the 

 nourishment which was destined for them. These parasitic masses have a 

 .completely independent power of growth and reproduction; and some kinds 

 of them can be propagated by inoculation, which conveys into the tissues of 

 the animal operated on, the germs of the peculiar cells that constitute the 

 morbid growth, these soon developing themselves into a new mass. So it 

 may be by the diffusion of the germs produced in one part, through the 

 whole fabric, by means of the circulating current, that the tendency to reap- 

 pearance (which is one great feature in the malignant character of these dis- 

 eases) is occasioned. But it would seem more probable, that this character 

 rather depends upon the presence of a morbid matter in the blood, of which 

 the formation of the Cancerous tissue is only the manifestation ( 330 note); 

 the local disease thus being the consequence of a constitutional cachexia, 

 rather than the coustitional affection the result of the local disease. 1 



rabbits, as stated in the first instance by M. Villcmin. It is certain that small par- 

 tides of tuberculous matter introduced beneath the skin of these animals gradually 

 travel along the lymphatics, affect the glands, and thence become disseminated 

 through the body ; but rabbits appear to be very liable to tubercular inflammation, 

 nnd it ha> been found that many other materials he.-idcs tubercle when thus intro- 

 duced lead to the formation of tubercle, or masses which cannot be distinguished from 

 tubercle. Experiments on other animals, though sometimes successful, have been 

 iipmi the whole less satisfactory. See Chauveau in Report of the second session of 

 the Freneli Assoc. for the Advance of Science ; Hering, Histologische uml Experi- 

 ment Sludien iilier der Tuberculosis, 1873 



1 See Dr. \Valsheon The Nature and Treatment of Cancer; Mr. Simon's General 

 Pathology, Leet. viii; Mr. Paget's Lectures on Surgical Pathology, vol. ii, Lect. xvi, 

 and the discussion on Cancer in the Pathological Society, reported in Lancet, vol. i, 

 1874. 





