IN SOUTH AMERICA, 



^55 



at Quito was only one hundred and feventy-five. The cannon ufed in thefe experi- 

 ments was a twelve pounder. 



I took advantage of the angles I had already meafured, and the diflances afcertained 

 in order to determine geometrically the pofition of thirty or forty points, as well in the 

 ifland of Cayenne as on the continent and the coaft, among others, of certain rocks, 

 and efpecially that called the Conftable, which ferves as a fea-work to fhips. I likewife 

 took the angles of elevation of the moft confpicuous capes and mountains. Their 

 height, well afcertained, would furnifti pilots with a much better dependence than mere 

 reckoning, for appreciating, on catching fight of them, (and that without other trou- 

 ble than confulting a fimple table,) their diftance from the coaft. It is but too well 

 known how neceflary, on approaching the land, an exaft knowledge of this is to the 

 mariners ; nor is the help which geometry affords to navigation, and which has been 

 hitherto neglefted, confined to this inftance alone. 



On another excurfion out of the ifland, in company with M. d'Orvilliers, we afcend- 

 ed feveral rivers on the main, and meafured their courfes ; I alfo frequently took the 

 latitudes, and thus obtained materials which, with the principal points I had before deter- 

 mined, may ferve to form an exaft map of this colony, which is the more wanting, as 

 there are none at prefent deferving the name. 



During my fojourn at Cayenne, I had the curiofity to try, if the venom of the poi- 

 foned arrows, which I had preferved upwards of a year, ftill retained its adivity, and 

 whether fugar be in reality as fecure an antidote as it is reprefented. The experiments 

 for determining thefe points were made in prefence of the governor of the colony, of 

 feveral officers of the garrifon, and of the King's phyfician. A pullet, flightly wounded 

 by a fmall arrow, wliich had been dipped in this poifon thirteen months before, and 

 which was blown through a farbacan, lived about half a quarter of an hour ; another, 

 pricked in the wing with one of thefe fame arrows, newly dipped in the venom diluted 

 with water and immediately withdrawn, feemed to faint a minute afterwards, was fhortly 

 feized with convulfions, and, notwithftanding it was made to fwallow fugar while in 

 this ftate, expired. A third, pricked with the fame arrow frefh dipped in the poifon, 

 having had the fame remedy immediately adminiftered, exhibited no fign of the leaft 

 inconvenience. I repeated thefe experiments afterwards at Leyden in prefence of the 

 celebrated profeffors, Miilfenbrock, Van Swieten, and Albinus, belonging to the uni- 

 verfity there, on the 23d January of this year. The poifon, the force of which was 

 neceflanly dhainifhed by length of time, and by the cold, did not produce its effefts in 

 lefs than five or fix minutes ; but fugar was given to no purpofe in another inftance, 

 the fowl which fwallowed it living but a ftiort time longer than the other *. The ex- 

 periment was not repeated. This poifon is an extraft made by boiling the juices of 

 certain plants, efpecially particular lianas. For the venom ufed by the Ticunas, which 

 is that I tried, and which is held in higheft efteeem of all the different fpecies known 

 along the river Amazons, I am^affured that more than thirty kinds of herbs or roots 

 enter into its compofition. Thefe Americans conftantly follow the fame procefs in pre- 

 paring it, that handed down to them by their forefathers, and this with as nice exacti- 

 tude as with us apothecaries in the compofition of the theriaca Andromachi, omitting not 



* Should this relation be peifeftly correA, it would appear that, although at a high temperature of 

 the air fugar immediately taken on the blood becoming infefted with this poifon, may be regarded as a 

 remedy and antidote, it lofes its efficacy when adminiftered in a cold climate. The temperature, at the 

 time the experiment was made at Cayenne, in July, would be about So* Fahr., while that at Leyden, ia 

 themidft of winter, was poffibly below 30*. Trans. 



the 



