AMYLOID DEGENERATION OF MINUTE ARTERIES. 415 



other hand assumes a blue, or under certain circum- 

 stances a red, or orange colour upon the addition of 

 iodine and sulphuric acid (p. 400). 



Owing to this multiplicity of reactions it is really still 

 very difficult to say with certainty to what class the sub- 

 stance belongs. Meckel has followed up the idea with 

 great care, that we have to deal with a kind of fat which 

 is more or less identical with cholestearine ; but we are as 

 yet unacquainted with any kind of fat which combines in 

 itself the three qualities of becoming coloured upon the 

 addition of iodine alone, of remaining colourless upon the 

 addition of sulphuric acid alone, and of assuming a blue 

 colour when acted upon by iodine and sulphuric acid. 

 Besides the substance itself does not in any way behave 

 like a fatty matter ; it does not possess the solubility 

 which characterizes fat ; and in particular no substance 

 can be obtained from these parts by extraction with 

 alcohol and ether, which possesses the peculiarities of the 

 original one. According to all this there is rather a 

 correspondence with vegetable forms, and the view may 

 still be maintained, that we have here to deal with a 

 process comparable to that which we see set in during 

 the development of a plant, when the simple cell 

 becomes invested with capsular layers, and gradually 

 grows woody.* 



* The analyses of amyloid spleens recently made by Kekule and Carl Schmidt 

 nave yielded such a large proportion of Nitrogen, that both these chemists have 

 come to the conclusion that the amyloid substance is of an albuminous nature. We 

 know, however, from experience, that the results furnished by these analyses of 

 whole organs are very little to be depended upon, so little indeed, that no chemist 

 was ever able to infer from any analyses he had made of the liver, that it was rich 

 in Glycogen. Only when we have discovered the means of isolating the amyloid 

 substance, shall we be able to come to any definite conclusion with regard to its 

 nature. 



To Schmidt's analyses of the corpora amylacea of the brain we cannot attach the 

 slightest importance, because his statements concerning them were founded upon 

 an error. He says, namely, he selected for his analyses a choroid plexus (from a 

 human brain) rich in corpora amylacea. But corpora amylacea are never found in 



