MISCELLANY. 
S5 
heated with diluted muriatic acid ; and then, according to the method of 
Smithson, brought in contact with gold and tin. After an action of seve- 
ral hours, the gold exhibited itself a little colored of a whitish gray, but 
very slightly. A counter experiment led me to the conviction that tin 
communicated to gold, under the influence of pure muriatic acid, a simi- 
lar gray color. This exeriment then was not decisive. 
Experiment 2. The saliva which afforded the matter of this experiment 
was also procured from those who had undergone frictions, and had not 
taken mercury by the mouth. It was of a very pale yellow color, with 
whitish flocculi. It was treated exactly in the same way as the preceding, 
except the modification of Smithson's method, to be indicated . It presented 
the same phenomena, especially the absence of evident coagulation, a large 
quantity of fatty matter was separated, and it gave in equal amount, by the 
action of sulphuretted hydrogen, a brownish yellow precipitate of sulphur; 
after this had been oxidized by nitromuriatic acid, and the residue by eva- 
poration treated with dilute muriatic acid, a small strip of gold leaf was 
introduced into the liquid with a piece of iron wire ; in fact, in a prelimi- 
nary experiment, the iron, under the influence of the muriatic acid, did 
not change the color of the gold or cause it to form an amalgam, except 
when mercury was present. The next day the gold leaf was evidently 
amalgamated, and assumed, when rubbed, the brilliancy of silver. 
To isolate, as far as practicable, the precipitated mercury, the gold leaf 
was doubled up and placed in the narrow part of a tube similar to that 
employed by Berzelius to separate arsenic from the sulphuret of this 
metal, by aid of carbonate of soda and hydrogen, and heated to redness 
in a current of hydrogen gas. It rapidly reassumed its yellow color, and 
afforded by degrees, in the straight portion of the tube, a delicate metallic 
layer, in which could be perceived, by aid of the glass, evident globules 
of mercury. 
To see if a portion of the mercury had been precipitated on the iron, 
this was submitted to the same trial, and yielded a thin layer, in which 
were evident very small globules, which, at the end of several weeks, 
were united together. 
This experiment demonstrated the presence of mercury in the saliva 
obtained during ptyalism, although in very small quantity. It is neces- 
sary at the same time to take into consideration, that large proportions of 
the mercury may have been volatilized during the reiterated evaporation 
of the saliva. A. G. V. 
Journ. de Pharm. 
Oil of Tea, by Mr. R. D. Thompson.— Travellers in China assure us 
that a species of fixed oil is as commonly employed as the olive oil in 
Europe for economical purposes, and that this oil is probably the product 
of the vegetable that furnishes tea, or another species of the same natural 
