IN MEDICAL SCIENCE. 39 



There is a series of organs in the body which has 

 long puzzled physiologists, — organs of glandular aspect, 

 but having no ducts, — the spleen, the thyroid and 

 thymus bodies, and the suprarenal capsules. We call 

 them vascular glands^ and we believe that they elabo- 

 rate colored and uncolored blood-cells ; but just what 

 changes they effect, and just how they effect them, it 

 has proved a very difficult matter to determine. So of 

 the noted glandules which form Peyer's patches, their 

 precise office, though seemingly like those of the lym- 

 phatic glands, cannot be positively assigned, so far as I 

 know, at the present time. It is of obvious interest to 

 learn it with reference to the pathology of typhoid fever. 

 It will be remarked that the coincidence of their changes 

 in this disease with enlargement of the spleen suggests 

 the idea of a similarity of function in these two organs. 



The theories of the production of animal heat, from 

 the times of Black, Lavoisier, and Crawford to those 

 of Liebig, are familiar to all who have paid any atten- 

 tion to physiological studies. The simplicity of Liebig's 

 views, and the popular form in which they have been 

 presented, have given them wide currency, and incorpo- 

 rated them in the common belief and language of our 

 text-books. Direct oxidation or combustion of the 

 carbon and hydrogen contained in the food, or in the 

 tissues themselves ; the division of alimentary sub- 

 stances into respiratory^ or non-azotized, and azotized, — 

 these doctrines are familiar even to the classes in our 

 high-schools. But this simple statement is boldly ques- 



