sift 



SIMMERING OF WATER 



Account of the 

 proccfs. Three 

 parts fulphuric 

 ether arc added 

 to one of folu- 

 tion of gold. 

 The gold is 

 taken up by the 

 ether. 



The inftrument 

 to be dipped into 

 the ethereal fo- 

 iution. 



Ertentlnl oils do 

 not fucceed well 



to overcome. The following is our method : To a faturated 

 folution of gold in nitro-muriatic acid, add about three times 

 the quantity of pure fulphuric ether ; Agitate them together 

 for a ftiort time. The gold will foon be taken up by the 

 ether in the form of a muriate, or nitro-muriatc of gold, leaving 

 the remaining acid colouriefs at the bottom of the veffel, which 

 ipuft now be drawn off by means of a ftop-cock, or other 

 fimilar contrivance. The acid being difcharged, the inftru- 

 ment to be gilt having been previoiilly well poliAied and 

 wiped very clean, is to be dipped for an infiant into the, 

 ethereal folution, and on withdrawing it, as inftantly wafhed 

 by agitation in clean water. This is elFenlial to get clear of 

 a fmall portion of acid neceflarily taken up with tlie racial ; and 

 if this be neatly done, the furface of the fleet will be com- 

 pletely and very beautifully covered with gold. 3ome liitle 

 degree of dexterity is required to perform the whole operation 

 well. 



] have tried fome of the elfential oils, knowing that they 

 will take the gold from nitro-muriatic acid ; but as far as I 

 went they did not apply for the purpofe of gilding : and as I 

 had found all I wanted in ether, I certainly did not profecute 

 the other experiments with much induftry. 

 I remain, with much refpe^t, 



pear Sir, 



*ir Your obliged fervant, 



J. STODAKT. 

 Strand, June 2 It 1 805. 



XII. 



On the peculiar Koife emiUed hj Water before it acquires {he 

 Temperature of hailing; zdiich is co7nmonly denoted by the 

 Word Siimnerirnr, W, N, 



Introduflion. »30ME time ago a philofophical friend who favoured me w ith 

 a vifit, mentioned in converfation that the fimmering of water 

 before it boils had formed the fubjed of enquiry betwe/^n 

 himfelf and other curious examiners of natural appearjlnces, 

 ss being a faft not yet well explained. It feemed to me 

 very remarkable, as I dare fay it will to my readers, that any 



of 



