476 [March 12, 



II. " On the Amyloid Substance of the Liver, and its ultimate 

 destination in the Animal Economy." By ROBERT 

 MCDONNELL, M.D. Communicated by WILLIAM BOWMAN, 

 Esq. Received February 13, 1863. 



(Abstract.) 



After briefly referring to the discovery of the amyloid substance of 

 the liver, and the earlier history of the subject, the author examines 

 the facts which have induced Dr. Pavy to conclude that this sub- 

 stance is not normally transformed into sugar during life. The au- 

 thor being led, after a careful repetition of Dr. Pavy's experiments, 

 to concur in his views, asks, If then the amyloid substance of the 

 liver be not converted into sugar, what becomes of it ? what is its 

 normal destination in the animal economy ? It is the object of the 

 memoir to attempt to answer this question, which, it must be ad- 

 mitted, is one of the greatest delicacy ; nevertheless there appears on 

 the whole to be evidence that the amyloid substance met with in 

 the liver is on its way upwards towards the more exalted or complex 

 immediate animal principles ; that, in fact, the process of healthy as- 

 similation tends, if the expression may be used, to promote it from 

 the rank of ternary (hydrocarbonous) to that of quaternary (azotized) 

 compounds ; and that its conversion into sugar is to be looked upon 

 as a deviation from this progressive course^-a dissimilative instead 

 of an assimilative process. In order to establish this view it became 

 necessary 



1st. To investigate the chemical and physiological relations of the 

 amyloid substance, not only of the liver, but of other organs and 

 tissues, and to test the very interesting results, which are for the most 

 part due to M. Charles Rouget. 



2ndly. To compare the portal and hepatic blood with each other, 

 and with arterial and venous blood derived from other sources ; and 



Srdly. To consider the relations to each other of the different 

 functions performed by the liver. For if it be true, as Lehmann, 

 Brown- Sequard, and others have asserted, that the fibrine and much 

 of the albumen of the portal blood vanishes in the liver, and that 

 at the same time that it destroys these azotized compounds it forms 

 its non-azotized amyloid substance, and excretes bile containing so 

 little nitrogen that it need hardly be taken into account, are we 



