348 
MISCELLANY. 
to be introduced into a matrass, and nitric acid diluted with half its weight 
of water gradually added, till the whole that is soluble is taken up by the 
acid. After the acid has ceased acting, the mixture is to be left to settle, 
the clear liquid poured off, and the residue, if any, washed with pure water, 
dried and weighed; its weight indicates the portion of insoluble matters 
mixed with the lead. 
This method has proved to us, 1st. That even the pure white leads 
leave a residue which may vary from ^ to 1 per cent. ; this residue is 
siliceous, and probably arises from the wearing away of the mill stones 
used in grinding the lead ; 2d, that other white leads contained from 
tVo t0 To"°o °f ^soluble matters; this was principally sulphate of ba- 
rytes. It is even probable that this proportion is much higher in the 
common white lead of commerce. M. Robiquet, in the article Ceruse, 
{Diet. Technologique, iv. 29,) states some of the proportions in which 
white lead is adulterated with this article. He says, that in Germany, 
what is called Venice white CVenesianer weiss J is formed of equal 
parts of carbonate of lead and sulphate of barytes ; that Hamburg white 
C Hamburger weiss J is composed of three parts of sulphate of barytes, 
and one part of carbonate of lead ; Holland white ( Hollander weiss J of 
the same proportions, and that another but inferior article, also called 
Holland white, contains seven parts of barytes to one of lead. 
Jour, de Con. Usuelles. 
Leaves of the Grape used as Moxa. — M. Bridel, of Bleu, has proposed the 
employment of the leaves of the common grape, (Vitis vinifera,) as a sub- 
stitute for the down of the Artemesia chinensis in the manufacture of 
moxa, of which these articles are usually fabricated. The following is 
the mode of preparation : 
At the end of autumn, when the frost has caused the fall of the leaves, 
and they are somewhat withered, they are collected and thoroughly dried 
in an oven at a moderate heat ; they are then beaten in a mortar until a 
soft cottony mass is obtained. To secure the down which results from 
this simple operation, they are enclosed in tight boxes, and kept in a dry 
place. This down is used to make the moxa in the same way as that of 
the Artemesia, and answers all the purposes as well. 
Formula for the internal administration of Iron. By Meurer. — The fol- 
lowing formula, though much recommended by chemists, has been little 
employed in medicine. It is an advantageous substitute for chalybeate 
waters, which are less efficacious than it, and much more expensive :— 
R. Sulph. ferri chryst. gss., sacch. alb. giss., tere simul et divid. in chart, 
xii. R. Bicarb, sodae gss., sacch. alb. giss., tere simul et divid. in chart, 
xii. Dissolve one packet of each separately in water, mix, and let it be 
