2!4 On the Operation of Medicines. 



eafe, may refleft fomc light on the general rati- 

 onale of its adtion. The ftrudture of the brain 

 is yet very imperfedlly known j but anatomifts 

 have fufficiently afcertained, that it is moft co- 

 pioufly fupplied with veflels of every order, 

 fo that about one tenth of the whole mafs of 

 blood circulates within it, although the weight 

 of the encephalon does not exceed one fortieth 

 part of the whole body*. On this large fyftenti 

 of vefTels, mercury may be prefumed to aft with a 

 force proportionate to its magnitude and extent. 

 And, in the inftance? when no falivation takes 

 place, it is not unufual for profufe fweatings to 

 occur about the head. An acceleration of 

 growth, alfo, to an extraordinary degree, is 

 frequently obferved, after the difeafe has been 

 thus fubdued. In one cafe, which fell under 

 my direftion in 1784, a young lady, nine or 

 ten years of age, of a noble family in this 

 county, increafed in (lature, two inches, within 

 the fpace of four months, fucceeding her re- 

 covery. 



Whence is it that a medicine, fo irritating as 

 mercury, can be conveyed into the courfe of 

 circulation, when even milk, or the mildeft 

 liquors, if transfufed into the blood veflels, have 

 been found to produce convulfions and death ? 

 Is it that what pafl*es by the lymphatics or ladeals 



* See Monro on the ftrufture of the nervous fyftera, 

 j3. 3, folio. 



is 



