THE LESIONS INDUCED BY POISONS. 359 



I. ENDOGENOUS POISONS FORMED LARGELY UNDER THE IN- 

 FLUENCE OF MICRO-ORGANISMS. 1 



1. Those which are formed in infectious diseases. (See Chapter 

 VIII., Part II., on Infectious Diseases.) 



2. Those formed in the body without infection. 



The most common and important metabolic poisons of this class 

 are those which are formed in the gastro-iutestinal canal through the 

 action of micro-organisms, mostly bacteria, upon the organic constituents 

 of the intestinal contents and secretions. ' The new chemical substances 

 thus formed become deleterious when absorbed into the body fluids, and 

 this may occur either when they are produced in unusual quantity or 

 when their elimination with the excreta is interfered with. When ab- 

 sorbed, some of these poisons may be demonstrable in the urine, and they 

 may give rise to a variety of symptoms which cannot be considered here, 

 but which are appropriately designated as marks of Enterogenic auto-intox- 

 ication. Such are dizziness, headache, some forms of tetany, gastro- 

 enteritis, etc. 



Endogenous poisons analogous in origin with these may be formed in 

 the bladder, in putrid abscesses, or in uecrotic tissues in various parts 

 of the body. Structural lesions, if such there be, occurring under these 

 conditions are as vet but little known. 



II. ENDOGENOUS POISONS FORMED BY THE BODY-CELLS -HISTO- 

 GENIC POISONS. 



It is only within the past few years that the studies on cell metabo- 

 lism have led to the belief that the body cells may not only under occa- 

 sional abnormal conditions form poisonous chemical compounds, but that 

 even in the normal processes some of the intermediary metabolic prod- 

 ucts may be inimical to the welfare of the body, if they be not constantly 

 rendered inert. This may be effected either by excretion or, as now seems 

 probable, in part at least through the influence of what have been 

 called the " internal secretions " of such glands as the thyroid, pancreas, 

 adrenals, hypophysis, etc. , or possibly in ways as yet wholly unknown. 



Thus there is a group of auto -intoxications due to the accumulation in 

 the body of the products of normal metabolism through defects in the 

 excretory apparatus, for example, uraemia in renal insufficiency or re- 

 tention of urine ; cholsemia in retention of bile ; carbonic-acid poisoning 

 in various forms and grades of asphyxia. Possibly some of the serious 

 symptoms following extensive burns of the skin and occurring in sun- 

 stroke and eclampsia are of similar origin. This may be called auto-intoxi- 

 cation throuc/h retention. 



On the other hand, there is a group of auto-intoxications which it is 

 assumed may in part at least be due to a failure of the organs concerned 



Consult in connection with this and the following section Eerter's "Chemical 

 Pathology." 



