S6 On Encaujlic Pam/ing. 



the valuable advantage that method has over the comma!* 

 oil-painting, which, notwithftanding the general opinion, 

 cannot have been unknown to the ancients ; for, bcfides olive- 

 oil, they were acquainted with that of fefanium, turpentine, 

 cedar, and nut oils. It is impofiible that in Egypt and Phoe- 

 nicia, where {o much ufe was made of flax, the oil pro- 

 cured in abundance from that plant mould have been un- 

 known. Thofc who have kept oil, or who have fpilt any 

 of it, whether nut or lintfeed oil, mull have remarked thas 

 it poffeffes the property of foon drying- by the effects of the 

 atmofphere; and therefore it may be eafily believed thai 

 mankind muft foon have, conceived the idea of employing 

 it, particularly for fhips, which, as Herodotus fays, were 

 painted with red ochre in the carlicft period?, and adorned 

 with figures and ornaments. The ufc of oil afforded paint- 

 ing a much Ampler and eafier mcthtfd than that of wax; it 

 muft therefore have been firft adopted, and the tranfition 

 from oil to wax muft be considered as a flcp towards bring- 

 ing the art to perfection ; becaufe encauftic painting is not 

 expofed to the irremediable inconveniencics that arife in oil- 

 painting, the value of which we extolled through ignorance, 

 and p railed as a new invention. 



Oil in general, and in particular drying oil which the 

 painters ufe, has naturally a ftrong inclination to combine 

 itfelf with the vital air or oxygen oi' the atmofpherc, and by 

 imbibing oxygen it becomes dry, and affumes the character 

 of rcfin ; but the colour then becomes darker, as is the cafe 

 with tranfparent turpentine, which gradually becomes a black 

 pitch. 



According to the new and more accurate method of de*< 

 compofing bodies, oil confilts principally of hydrogen and 

 carbon. By coming into contact with the atmofphcre, and 

 abforbing its oxygen and light, it undergoes a flow and im- 

 perceptible combuftion, which is not elfenlially different 

 from the fpeedy and violent which it would undergo in the 

 common mode of burning. U fijft paiTes, by imbibing oxy- 

 gen. 



