american institute. . 555 



Polytechnic Association ov the American Institute, ) 



January 27th, 1860. j 



Prof. Mason, chairman. Jolin Johnson, Esq., secretary pro tem. 



Mr. John M. Wykoff showed some interesting experiments illustrative 

 of his method of saving gold particles from miners' waste. 



1st Experiment. — Finely ground quartz containing iron, silicia, and 

 gold being thrown into water, the silicia. which is the lightest, sank, while 

 the heavy iron and gold floated. 



2d Exjjeriment. — Mercury was introduced into the glass tube in which 

 the water and ground quartz had been put, and heat was applied by means 

 of a spirit lamp. Long before the water boiled the mercury went into 

 violent ebullition ; globules rising through the water at the sides, and sink- 

 ing in the middle of the tube. 



Mr. WykofF stated that this ebullition takes place when the heat is not 

 more than 90 degrees, though mercury requires 660 degrees to convert it 

 into vapor. 



His theory is, that though mercury is thirteen times heavier than water, 

 yet the water insinuates itself between the mercury and the bottom of the 

 containing vessel, is converted into very elastic steam, and drives or blows 

 up the mercury through the water. 



Mr. Butler controverted this theory, not with the view of proving it 

 false, but of eliciting more information on the subject. 



Professor Hedrick mentioned a laboratory experiment, which confirms 

 the fact that gold, though nineteen times as heavy as water, floats under 

 some circumstances. Gold dissolved by the aid of oxalic acid will float. 

 Indeed, it is well known that minute particles must float. It is also well 

 known that heat aids precipitation of gold from solution. Therefore Mr. 

 Wykoff 's plan seems to accord with received chemical theories, but to put 

 it to strict test he would propose ; 



" That a committee be appointed to investigate Mr. Wykofi" 's method of 

 saving gold." 



The committee, consisting of Prof. Hedrick and John Johnson were so 

 appointed. 



Mr. G-arvey exhibited some specimens of prints produced by Turner's 

 " Photolithographic Process." 



The specimens, " S7£?i«?/ Side^^ and ^^ Washington Heights,^' J. Q. 

 Bennett's place, were greatly admired. 



The report of committees being called for, they reported as follows : 



James Montgomery's Steam Gauge. 



The committee respectfully report — 



That they have examined the Pressure Gauge submitted to their inspec- 

 tion, but have not seen it under pressure, nor had opportunities to test it j 

 they can therefore only give an opinion on the principles of its construc- 

 tion. 



