204 LYMPHATIC SYSTEM. 



with those symptoms : to which may be added, that another 

 reason why these poisons do not constantly affect the lymphatic 

 glands in their way into the body, may be the lessened sen- 

 sibility of these glands in some particular cases ; whence the 

 same poison which at one time would have produced the worst 

 effects, may at another pass through these glands without in- 

 flaming them. 



And lastly, not only obstructed lymphatic glands sometimes 

 occasion dropsies, but also whatever impedes the passage of the 

 lymph into the veins ; whether it be a thickening of the coats 

 of the jugular or subclavian veins near the termination of the 

 thoracic duct, or a tumour of the aneurismal, scirrhous, or 

 encysted kind, contiguous to any part of the lymphatic system ; 

 for such tumour, by compressing the lymphatic vessels, may 

 prevent the return of the lymph, and may thereby occasion a 

 dropsy or oedema of the parts from which these vessels originated. 



Upon the whole, whoever carefully views the lymphatic sys- 

 tem must be convinced that, as it explains and points out the 

 cure of many diseases, it deserves the attention of the practi- 

 tioners of the healing art. And as it is so generally diffused 

 through the animal kingdom, it strongly claims the regard of 

 those who wish to inquire philosophically into the animal eco- 

 nomy, especially as, by the knowledge of this system, we are 

 now flattered with the hopes of ascertaining the use of the 

 lymphatic glands, the thymus, and the spleen ; which discoveries 

 are to be the subjects of the Third Part of these Inquiries. 



