-5 On Dr. Mltchlll's Theory 



lants or not. This doubt is repeated in § xix. where, ex- 

 prefling his ideas of the manner the exciting powers aft upon 

 excitabiUty, he feems to confider poiTons and contagions as 

 exceptions to the general rule of action: " nifi quod venena 

 ct contagiones excipi pofl'e videntur." And although, in the 

 two following paragi-aphs, he endeavours to fhcw that thefe 

 fubftances are jlhnulanis, and act upon the living body after 

 the manner of other iHniuli, flill he is fo wholly filent as to 

 their nature and conflitution, and fo entirely dcftitute of ex- 

 perimental proof or demonflrative rcafoning, and withal fo 

 brief and general in his remarks, that nothing folid and fotif- 

 faftoi-y is afforded in that part of his work which treats of 

 thefe matters. 



In converfation with this original though unfortunate 

 man, Dr. JMitchill acquired incorrect information on the 

 matter of thefe poifonous fubftances and their manner of 

 acting ; the fum of Brown's rcafoning but tending to fliew 

 that, as all other f.ibftances according to his hypothcfis were 

 llimulants, fo'ijons and contiigioizs could not, fnjm the nature 

 and analogy of things^ aft in any other way than by ftimu- 

 Jation too. 



Thus it appeared to Dr. jNIitchill, when he returned to 

 America in 17S7, that that ileld of phyfical fcience, which 

 included the production, operation, and extinguifliment of 

 poifonous fluids, lay almoft wafte and uncultivated. On turn- 

 ing over the Encyclopaedia, there fcarcely appeared a fubject 

 whofc invcftigation promifed greater good to mankind, or 

 f.'.ircr fame tc the inveftigator, than the hillory of thefe nox- 

 ious pvoduftions. Not long after this time the Medical So- 

 ciety of the State of Delaware propofcd a pri'ze-queftiou, 

 '' What was the hurtful power wliich produced the febrile 

 dlftcmpcrs of that region?" And Dr. Mitchill was folicitcd 

 bv his friend Dr. Ed. Miller, then fecretary of the fociety, i(y 

 compete for the prize. Eut being at that time engaged in 

 the ftudy of the law, and alio in the politics of his coun- 

 try as a member of the kgillaturc, he declined undertaking 



any 



