PERMANENT WHITE POR WATER COLOURS. S3 



charctf^l. It is surprising that he is not aware, that Dr. 

 Henry fpund this gas to be a mi^cture of car bu retted hidro- 

 ■gejiaiid carbonic oxide; and that thefoimation of carbonic 

 Void mi^hi be expected oa passing a mixture of it and oxi- 

 "raariatic gas frequently through lime water, as he experi- 

 enc«^d, this being the result when a mixture of pure carbo- 

 lic oxide and oximuriatic gas is thus treated. 



There is nothing farth^er in Mr. Murray's communica- 

 «bns, that requires notice, excepting a misuse of names. 

 tie soinetitnes writes properly, calling nae " Mr. J. Davy,'' 

 at other times, improperly "Mr. Davy," thus creating 

 confusion, and rendering it impossible to distinguish opj- 

 'nions and stiite-neuts which belong lo me, and for which 

 I alone am answerable, from those of Mr. Davy, my brother. 



I am, Sir, 

 Your obedient humble servant, 

 ^f^r}dony.4«gmthe^iK JOHN DAVT. 



VI. 



Method of preparing a beautiful and permanent White fiir 

 Water Colours. In a Letter from Mr. Grover Kemp. 



To MR. NICHOLSON. 

 SIR. 



ii-T is a very just remark of the ingenious and candid Chap- It is our duty 

 tal, that, ** at a time when the minds of all men are bent toconufluni- 



^ . , ,. , . • • , . catcall we can 



on confirming public happiness, every citizen owes to his to the public 



country all thevgerv ces that his situation allows him to ac- 

 complish ; he should be eager to pay to society the tribute 

 of those talents with which Heaven has favoured him; and 

 there is no one who is not able to bring some materials to 

 the foot of that superb edifice, which a virtuous government 

 is erecting to the happiness of all*:'' and believing with this 



•See "El€metis de Chimte par M. Chaptal," Montpellier edition, 

 1 790. Advertisement, p. 5. 



Vol. XXX.— Sept. 1811. celebrated 



