Electro-Magnetic Experiments 63 / M. Van Beek, Szc. 
ving been previous to ours, though, I can assure you, that we 
received the number of the Journal in which they are commu- 
yiicated after my letter to you had been sent oflP. Be this as it 
may, we cannot help feeling pleased with having been employed 
in making experiments on a subject which attracted the notice 
of so illustrious a philosopher as Sir Humphry Davy. 
I shall now proceed to relate some further experiments ; but 
as I keep no minutes of my letters, it is not impossible that some 
of those which I am going to state are already contained in my 
former communication. 
J, Having taken a steel-plate ABCD, Fig. 1. Plate II., we laid 
on it a glass-pane, and on the glass was placed a communicating 
brass-wire E ; through this the Leyden battery was discharged ; 
the end E of the wire communicating with the interior coating, 
the end F with the exterior coating of the battery. The steel- 
plate became magnetic by the discharges ; the whole of the part 
ABFE having acquired a north, and the part FCDE a south pole. 
S. We took a square plate of steel ABCD, Fig. 2. ; on this, 
as usual, was laid a glass-plate, and on this a connecting brass- 
y/ire, bent as shewn at EFGHIKL. Through this wire the 
electric discharge of the battery was transmitted, and the steel- 
plate became magiietic, as shewn in the diagram. The end L 
of the wire communicating with the interior, the end F with the 
exterior coating of the battery, the parts BF and KC of the 
plate had north, the parts AF and FD had south, magnetic po- 
larity. 
3. We took a steel-cylinder. Fig. 3. of ^bout an inch in dia- 
meter, and three inches long, perforated through its axis AB. 
Through this aperture was thrust a glass-tube, open at both 
ends, in which a brass communicating-wire was placed. Re- 
peated powerful electric discharges gave no magnetism whatever 
to the cylinder. 
4. We had a steel-cylinder, Fig. 4,, made of two halves, 
kept together by two brass-rings, and perforated in the same 
manner as that described in the former experiment. When the 
brass-rings KL and IH are taken off, the cylinder separates in- 
to two halves ABMG and CDEF. Through the axis of the 
cylinder, whilst kept together by the rings, strong discharges 
were passed, and the cylinder, as in the former experiment, shew- 
