J 14 ON THE POISON 



number of the animals was faved, though they Were 

 fuch as he knew to be moft eafily killed by the poifon, 

 and the death of others was retarded. He alfo tried 

 a weak folution of the fame remedy internally with 

 remarkable fuccefs, and upon the whole he congratu- 

 lates himfelf in feeing his labours at length rewarded 

 by the difcovery of a true fpecific remedy for the bite 

 of the ferpent. 



FoNTANA was led to the ufe of this remedy by no 

 previous theory, for neither before, nor after his difco- 

 very, does he attempt to account for its effeds, and the . 

 infinite variety of his experiments, as well as the fidelity 

 and accuracy with which he relates thern, entitle him 

 to our confidence and praife. 



I AM now to explain in what manner, the fuccefs- 

 ful ufe of thefe fubftances fupports the principles we 

 have been endeavouring to eltablilh: and here again I 

 am under the neceihty of alTuming fome fad:s, which 

 are eftabliflied and indifputable. 



1. Oxygen enters into the compofition of all acids, 

 and is the principle, as its name imports, upon which 

 their cicidity depends. 



2. Metals are united with oxygen under various 

 circum fiances, but chiefiy in two ways : the firft is by 

 burning them in an open fire, or to fpeak more cor- 

 re6tly, by the contatt of heat and air, when they are 

 converted into metallic oxyds : the fecond^ by the de- 

 compoiition of acids, when they form compound 

 falls. 



^. Oxygen is attracted by different metals with 

 different degrees of force, thofe which attra6t it with 

 the leaft force, are tlie perfect metals, as platina, gold, 

 (ilver, heiice they cannot be converted into an oxyd by 

 cxpofure to heat and air, except at very high tempe- 

 rature. 



