218 Description of a Magnetic Electrical Machine. 
but differing inasmuch as that they are also soldered to the two brass 
cups 6 6, which are intended to hold a little mercury. Connect it 
by copper wire ; a little acid or any salt will increase the effect by 
forming a better conductor with M, N, as in the figure. Here Q 
must work on the single break, H. C, D, two platina plates, having 
two copper wires soldered to them to connect them with M, N; on 
placing a piece of litmus or turmeric paper between them that has 
been adeialy wetted with some neutral salt, its decomposition is 
shown by the alteration in the color of the paper. You may even 
transpose the colors by altering the position of the break H. 
Description of the quantity Armature. 
This armature differs materially from that which is employed for 
intensity. The latter, as already stated, has two coils of one thou- 
sand five hundred yards of insulated copper wire ,’, of an inch in di- 
ameter. The inventor has also tried silver wire, which he found to 
be superior to copper in the proportion of nearly three toone. The 
quantity of iron in the cylinders also is much smaller than in the 
quantity armature, whose effects are greatest when the quantity of 
iron in the cylinders i is increased, and the length of the copper wires 
diminished ; the wire at the same time for quantity being much 
thicker. The quantity armature contains only forty yards of insula- 
ted copper wire ;'; of an inch in diameter. 
