64 PATHOLOGY. 



semi-transparent appearance. It feels like a piece of soft wax, 

 or of lard and wax combined. — (Wilks.) It cuts into portions 

 of the most regular sliape, with sharp angles and smooth 

 surfaces, and the thinnest possible slices may be removed by a 

 sharp knife for microscopical examination. They are abnormally 

 translucent. Water and alcohol, acids and alkalies, do not produce 

 any change upon the transformed parts, which may be kept for 

 a length of time without decomposition. The organs affected 

 are increased in volume, in solidity, and in weight, absolute and 

 specific. Anaemia is predominant; but the colour of the blood, or 

 of tissue, shines through the semi-transparent morbid substance. 



Amyloid degeneration is generally widely diffused, so much 

 so, that a constitutional state of ill-health seems associated with 

 its production ; and in cases preceded by a local disease, such as 

 caries of a bone, the degeneration may be found in the adjacent 

 lymphatic glands only. — (Billeoth.) This is the earliest appear- 

 ance of the degeneration yet recognised. — (Aitkex.) 



The amyloid substance almost invariably affects the capillaries 

 and small arteries. Their coats become thickened by the deposit, 

 and at last pellucid, transparent, and hyaline. The deposit then 

 extends into the surrounding tissues, and invades both its cells 

 and intercellular substance. The cells become filled with the 

 amyloid material ; they gradually increase in size, become round 

 and regular in shape, their nuclei disappear, and they are finally 

 converted into homogeneous bodies, having a translucent or 

 glistening appearance. The effect of this change in the nutri- 

 tion is to impair or even destroy the function of the affected 

 organ : — 1st. By obstructing its circulation, by diminishing the 

 calibre of small arteries ; and 2cl. By the pressure of the new 

 material upon its proper substance, whereby secondary atrophic 

 changes are induced. It is important to remember that this 

 form of degeneration is secondary to some serious constitu- 

 tional disease. It is supposed that it is due to some change 

 in the blood, and that the deposit is in reality an infiltration 

 of an albuminoid or fibrinous substance from the blood into 

 the tissues, which there becomes consolidated. In the human 

 being it is found to succeed chronic suppurative diseases, and 

 the way in which the tissues are affected is as follows: — 

 The change almost invariably commences in the small nutrient 

 blood-vessels, and extends from them to the surrounding parts. 



