422 LECTURE XVII. 



have a grey, translucent, sometimes slightly wax-like 

 appearance ; but this, however, is so little characteristic, 

 that no inference can with certainty be drawn from it 

 with regard to the internal changes, and the only possi- 

 bility of determining the point, when one has no mi- 

 croscope at hand, consists in the direct application of the 

 test. One need only brush a little iodine upon the 

 surface, and a number of densely aggregated, yellow- 

 ish- or brownish-red spots are soon seen to start up, 

 whilst the interjacent mucous membrane merely looks 

 yellow. These red points are the villi of the intestine/ 

 and if one of them be placed under the microscope, the 

 walls of the small arteries and even of the capillaries, 

 which ramify in them, and sometimes also the parenchy- 

 ma, are seen to be coloured iodine-red. 



The most important disturbances of this kind with 

 which we are as yet acquainted, are those which arise in 

 the kidney. A large proportion of the cases of Bright's 

 disease, especially of the chronic ones, are assignable to 

 this change, and must therefore be separated from many 

 other similar forms as constituting a special, altogether 

 peculiar affection. Kidneys affected in this way were 

 called in Vienna, at a time when the chemical reaction 

 was not yet known, lardaceous kidneys (Specknieren). 

 I must however again remark that it is impossible to 

 distinguish immediately with the naked eye, whether 

 this particular change has taken place or not, and that a 

 part of the so-called lardaceous kidneys exhibit nothing 

 more than a kind of induration. Not until iodine has 

 been employed can a diagnosis be readily made. I p a 

 solution of iodine be applied to a quite anEeinic cortex, 

 a number of red points usually first appear which cor- 

 respond to the glomeruli, and sometines fine streaks also, 

 which are the afferent arteries ; and next to this, when 

 the disease is very severe, red parallel lines are also 



