^ XltUit)' of Sirds in defiroyln^ tiift^i, 



and Defcartes, down to the excellent Compendious Coitrfei 

 of the Mathematics very lately publiflied by E. M. G. Le- 

 moine (d'Kiroies) and Dr. Mutton, that the vhuula are vQrf 

 feldom^if e\er,omilled, where they ought to be inferted; an3 

 that they arc fomctimes inferted where, with but little danger 

 of miikike, thev might have been omitted. 



In the original (as well as the tranflation) of the preced- 

 ing little work, the ingenious author has not omitted a fmglc 

 vinculum which could afl'e6l the fenfe of his fnnpleft cxpref- 

 lions ; and, in feveral iuitances, he has inferted that charac- 

 ter where it might have been fpared. Plence it was tiext to 

 impolfible for me to fufpe6l that he (or the printer) had for* 

 gotten to infert it in the inllance in queflion, and thus had 

 inadvertently made the only expreflion, at all deferving the 

 name of complex, a folitary exception to an indifpeniible rule, 

 which otherwife had been univerjally obferved, throughout 

 the piece. — W. D. 



y\. On the VtUify of Birds in dejlrryhig InfeBs and other 

 Produdions hurtful to Mankind. 



W HEN the deftruftion and wafte of the fruits of the 

 earth, occafioned by birds and infefts, is duly confidered, 

 we ceafe to wonder at the anxiety of agriculturifts and others 

 in feeking out means for the deftru(Slion fometimes of the one 

 and fometimes of the other, according as particular circum- 

 fiances have made the havoc of either more or lefs obfervable 

 on their fields. Indeed, on a hafty view of the fubjed the 

 only matter that ilrikes the mind with furprife is, that un- 

 wearied and unceafing means have not been generally fol- 

 lowed to extirpate many of thofe pefts which all mankind 

 feem equally to have an intereft in deftroying; for, every 

 thing that diminiflies the profits of the farmer adds to the 

 price of the neceflarics of life — and, confequently, adds to 

 the quantum of labour performed by every individual. 



But, in waging war againft the feathered tribe there 

 ought to be fome difcrimination, and the fa6t on a clofe ex- 

 amination of the fubjec^ will tiirn out to be, that we ought to 

 form an alliance with fome of them, as far as protection to- 

 wards them can favour that end, with the view of the auxi- 

 liary aid they may afford us in extirpating the hoftile bands 



of 



