266 On constructing Electric Columns. 
Dutch-gilt embossed paper with a brush, by which method a 
triple disc was obtained, consisting of Dutch metal (copper), 
paper and xinc. Perhaps some one may be able to describe the 
exact method of making the Dutch-gilt paper; if so, I shall 
esteem it a favour to be informed of it. I understand that the 
metal is formed of copper principally, but of what other sub- 
stance is unknown to me. It appears to me that a considerable 
advantage may be gained by the above-mentioned process, both 
in time and labour, as these plates or discs are much more easily 
punched out than plates of zinc, and the placing them in a co- 
lumn is also much more easily doue on account of there being 
only one kind of disc, therefore less chance of a mistake is 
likely to occur in the disposition of them. If paper with silver- 
leaf \aid on it, as described in Philosophical Magazine, vol. xxxv. 
p- 205 (March 1810), were used instead of Dutch-gilt paper, 
the effect would probably be stronger, and still more so if dises 
of silvered paper and discs of paper with powdered zinc were 
used, as the paper would then be more capable of imbibing 
moisture from the atmosphere than when both sides are coated 
with metal. As the gold-leaf electrometer, commonly used for 
experiments with the electric column, is rather an expensive 
one, and troublesome on account of the delicacy of the gold- 
leaves, it may not be unacceptable to many of your readers to 
be informed, that a metal-leaved electrometer of great sensibility 
may at a very reasonable cost be made, with a small lamp-glass 
fitted up with a mahogany top and base; the leaves are to be 
made of Dutch metal fastened to a thick piece of brass wire or 
slip of wood fixed into a piece of cork (which is to be glued on 
to the wooden cap) ; slips of tin-foil or Dutch-metal are to be 
pasted on two opposite -parts of the glass cylinder as usual. 
Electrometers made with Duéch-metal as above mentioned, 
are strongly affected by a person’s finger being placed on them, 
if he suddenly rise from a chair (with a horse-hair seat) and stand 
upon a dry fire-hearth, the electric effects being produced by 
his woollen clothing rubbing against the horse-hair chair. 
A dry fire-hearth being found to be @ very good insulator, 
I frequently make use of it instead of a stool with glass legs. 
Should it be found that zinc dust laid on, as in the foregoing 
account, does answer the purpose desired; this method may 
be worthy of the attention of the philosophical-instrument-ma- 
kers, as they might probably find a sale for this (as it may be 
called) electrical paper. If zinc could be procured in as thin 
leaves as silver or Dufch-metal, it probably would be better for 
electric columns than zinc dust. 
April 47, 1816. B, M. Forster. 
LVIII. Re- 
