3^0 Royal Society of London. 



perties of metallic precipitates, (Opufcula, torn. ii. p. 385), 

 and efpecially notices the various colours of the pruffiates; 

 but neither he nor any other chemift, as far as I am ac- 

 quainted, has pointed out to artills the utility of pruffiateof 

 copper as a pigment. During fome late experiments, I was 

 much ftruck with the beauty of this precipitate, and was 

 therefore induced to make feveral trials of it as a paint : the 

 refults exceeded my moft fanguine expe6tations. I after- 

 wards prepared a large quantity, which at my requed feveral 

 gentlemen (particula'rly B. Well, efq. P.R.A., John Trum- 

 bull, efq., and firH. C. Englefield,) were fo obliging as to try 

 in oil, and in water ; and I have had the fatisfaition to learn, 

 that in beauty and intenfitv it furpalTes every brown paint 

 now in ufe, with the additional advantage, that, by reafon of 

 its purple tint, it forms with white various {liades of bloom or 

 lilac colour, which do not appear liable to fade like thofe 

 which are formed by means of lake. 



The pruffiates obtained from acetite, fulphatc, nitrate, and 

 muriate of copper, are all very beautiful ; but the fineft and 

 deepeft colour is afforded by the muriate. I have found alfo 

 that pruffiate of lime can be better depended upon for this 

 purpofe than pruffiate of potafli. The beft mode, therefore, 

 of forming this pigment, is to take green muriate of copper, 

 diluted with about ten parts of diftilled or rain water, and to 

 pour in pruffiate of lime until the whole is precipitated : the 

 pruffiate of copper is then to be well waflied with cold water 

 on the filter, and to be dried without heat. 



LXIII. Proceedings of Learned Societies. 



ROYAL SOCIETY OF LONDON. 



x\N account of a journey to the fummit of Whararal, a 

 mountain in the ifland of Owhyhee, by Mr. Archibald 

 Menzies, naturalift on board the Difcovery, captain Van- 

 couver, was read on the 9th and 16th of December. 



In January 1799, ^^^^ Difcovery, being ftationed in Ka- 

 rakakooa bay, Mr. Menzies was defirous of making a bota- 

 nical excurfion into the ifland of Owhyhee, in company with 

 fome othcr'gcntlemen of the expedition, and, in particular, 

 of afcending a conical mountain in the neighbourhood, called 

 Whararai. For this purpofe he was furnifhed with a nume- 

 rous company of attendants by the king of the ifland, under 

 the command of one of the chiefs, who was made rcfponfible 

 for his fafety, and for his perfcft accommodation with pro- 

 vifions of all kinds, and who executed his tafk with as much 



fidelity 



