68 On the Onager of the Ant'icnts, 



the flame had afceniledj as flame, from the fiicl in the fur- 

 nace ; which is bv no means the cafe. A confi'deration of 

 this fimple fa£l will convince any perfon that it is not an 

 inconfidcrable proporlion of the fuel that is thus wafted. Nor 

 is this the onlv lofs fuliained; tlie qmnlily of heat required 

 not merely to render Inch a portion of the fuel volatile, but to 

 give to it a tcmpevature able to produce the eB'eol of which 

 w-e have taken notice, is itfelf furniflicd at the expenfe of an 

 extra and unneceliary quantity of fuel ! 'i'hc whole waftc in 

 manv cafes is, we are perluaded, not lefs than au eighth of 

 the whole fuel employed. 



XII. Ohfervations on the Onager of the Anfienls, or the real 

 inid Afs. Bj Prof e for Pa L L A s * . . 



o 



UR •cabinets of natural biftory contain a multitude of 

 anim lis, and other natural prodaiitiousjfroin both the Indies, 

 U'hich are even fcarce in their native countries, and which, 

 on that account, are fent 'as rarities to Europe : on the other 

 hand, manv fpecies common in diftrifts not very remote from 

 Europe are ftill imperfectly knoun, and therefore the exiit- 

 ence of many of them is accounted doubtful, becaufe people 

 do not give themfelves the trouble to examine the places 

 where they are found. Of the truth of this obfervalion, the 

 wild aft, or onager, fo often mentioned by antient authors, is 

 a remarkable inllance, Fromthe filcnce of moft of the mo- 

 dtrn travellers in the Eaft: refpecling it, one might alnioft be 

 induced to conclude that the race of this animal is become 

 entirelv extiadt. An evident caufe of this is, that the Eu- 

 ropean's have very little intercourfe with thofe dillrifts from 

 which the Romans procured v.'ild afleS for breeding mules. 

 As our travellers are obliged, for the iakeof fecurity, to go 

 in larjre caravans when they pals tlirough the Afiatic deferts, 

 where thefe animals refidc, thev Can Tee only a very fmall 

 portion of the country. It is thcrtforc not furprifing, that 

 animals noted for their fliynefs and timidity fliould efcape 

 their obfervation, I have been aflured, in a letter from 

 M. Niebuhr, the celebrated traveller in Arabia, that during the 

 whole courfc of his travels he never faw a wild afs, not even 

 in Svria, where, at the time when that country was vifited 

 by liauwolf t, who fpeaks of thefe animals, they mu ft; not 

 have been very uncommon. Befides this old naturalift, and 



* From Nene l^ordifcbe B/'ytiu^e, by profcflbi- Pallas, vol. ii. 

 t Rauwolf's Reife, Ai:^. 15S3, 4ro. p. 65. 



by 



