Domesttc Intelligence. 199 



^ 



which is laid upon it with a brush, is moistened with ^in, or 

 some other spirit. The gold leaf, cut up by a round-edged 

 knife into pieces of suitable size, is taken up on a flat hair- 

 brush, and brought with the gold downward very near to 

 the place to which it is to be applied. When it comes with- 

 in a short distance, generally about half or three-quarters of 

 an inch, without any farther attention from the artist, it 

 suddenly flies from the hair-brush to the surface on which 

 it is to be laid, and clings to it, and embraces it with such 

 delicacy, as to cover every roughness. The ^old, apparent- 

 ly, makes just such an effort, as it does wlicn attracted in 

 the gold leaf Electrometer, and it appears to arise from the 

 same cause, viz. an electrical attraction. This attraction 

 is obviously produced by the evaporation of the spirits. 



Evaporation is well known to produce ekctrical excite- 

 ment, and to generate opposite states of electricity in the 

 contiguous bodies. We should therefore expect the attrac- 

 tion to be strongest in the case of those bodies which evap- 

 orate most readily — accordingly the gold leaf is less pow- 

 erfully attracted when water is substituted for spirit. 



The success of the gilder appears, in these cases to de- 

 pend very much oa the exertion of a principle which he is 

 very little aware of. It would seem, that but for this, it 

 would be scarcely possible to apply the leaf with en- 

 tire precision, to all the varieties of surface produced by 

 the carver. We have thought it worth mentioning, as a 

 happy illustration of a scientific principle, occurring in the 

 practice of the arts. 



5. A Fermenting Pond. 



Extract of a letter to the Editor from Mr. Thomas H. 



Webb, dated Providence, Oct. I, 1821. 



I lately visited a pond in Sharon, (Mass.) known by the 

 name of Mash-Pog pond, from which great quantities of 

 lenticular argillaceous oxid of iron, and what is called 

 cake ore, are procured. The pond from about the middle 

 of August to some time in September, presents the singular 

 appearance of working or fermentiiig, as beer does when 

 neyr. Whether this appearance is peculiar to this pond, I 

 do not know. 



Re;nm^k. — It would be well to catch some of the gases, 

 which, without doubt, cause this intestine motion : most 



