486 THE AUTOGENOUS DISEASES. 



walls permit the passage of proteid bodies, to which the same 

 structure in the adult is impervious. When peptons and albumoses 

 are injected directly into the blood they act as powerful poisons. 

 They destroy the coagulability of the blood, lower the blood pres- 

 sure, and in large quantities cause speedy death. The lassitude and 

 depression following a full meal, especially one rich in proteids, is 

 attributed to the absorption of peptons, but so far there is no 

 scientific evidence bearing on this point. Pepton and albumose are 

 frequently found in the urine, but whether the substances found in 

 this excretion have been absorbed from the intestinal wall or have 

 been elaborated elsewhere in the animal body, no one knows. 



2. That certain secretions and excretions of the human body are 

 poisonous when brought in contact with tissues with which normally 

 they have no relation, is well known. We have already referred to 

 the action of normal bile when brought in contact with the pancreas, 

 and that the bile acids have a hemolytic action when absorbed into 

 the circulation is a fact which has long been known. Why it is that 

 the bile has a destructive action upon the cells of the pancreas and 

 no such effect upon the cells of the liver, or upon the structures of 

 the gall passages and intestines, we do not know. It is rather strange 

 that with the close relation between the pancreas and the gall blad- 

 der that the contents of the latter do not more frequently reach the 

 former. So far as we know this is an accident which very seldom 

 happens, and without the experimental demonstration which has 

 been made on this subject it would be quite impossible to account for 

 the alterations observed in the pancreas in the few instances in which 

 this has happened. 



3. It is the function of certain organs of the body to prevent the 

 passage of certain substances into the general circulation. In other 

 words, it is the duty of certain groups of cells to protect other com- 

 munities from harmful agents. The rich therapeutical results which 

 have followed experimental investigations of the relation of the thy- 

 roid gland to myxedema and cretinism are illustrations under this 

 head. The probabilities are that myxedema is a form of mucinsemia, 

 and that the introduction of an excess of mucus into the other tissues 

 is prevented by the normal action of the thyroid gland. This pro- 

 tective action of certain glands is manifest both in certain internal 

 and external secretions. That the bile consists essentially of excre- 

 mentitious material is generally believed and in fact has been demon- 

 strated. It is not necessary to multiply illustrations of this kind. 



4. That the undue retention of excrementitious substances fre- 

 quently leads to disturbances of health, is well known. The ab- 

 sorption of effete matter from the intestines and the retention of 

 substances which should be eliminated by the kidneys may lead to 

 disastrous results. We have only to mention as an illustration 

 under this head the retention of urates in the causation of gout, and 



