378 Loan Collection of Scientific Apparatus [July, 
Glass tubes prepared by Faraday for testing the magnetic 
and diamagnetic character of gases.— The tubes containing 
the gas to be examined were suspended in the magnetic field 
of a powerful magnet, the result being either attraction or 
repulsion of the tubes as the gases they contained were 
either magnetic or diamagnetic. 
Bars of borate of lead glass, made and used by Faraday, 
for the aCtion of magnets on polarised light. 
The diamagnetic box of Faraday, containing spheres, 
cubes, and bars of diamagnetic metals ; tubes of various 
liquids, bars of borate of lead, glass, various crystals, 
cradles, supports, &c., used by Faraday in his researches 
on diamagnetism. 
Siberian loadstone and spark apparatus. — This was the 
loadstone employed by Faraday in his experiments on mag- 
neto-eleCtric induction, from which he first obtained the 
induction spark. 
Glass globes for producing electricity by rubbing with the 
hand. The globes are caused to revolve by means of mul- 
tiplying wheels and a band of rope. The globes may be 
exhausted when they become luminous ; the greatest 
amount of electricity or “ fire ” was obtained from them 
when they were exhausted. In the one with a large brass 
cap a small wooden disc could be inserted with threads dis- 
tributed round its edge ; when the glass was excited the 
threads stood out from the edge of the disc. Constructed 
about a.d. 1720. — (Museum of King George III., King’s 
College, London.) 
Daniell’s battery, employed in researches by Prof. Daniell. 
Early voltaic batteries: — Babington’s, Cruikshank’s, 
Wollaston’s, and Sturgeon’s. 
Hare’s calorimotor, or deflagrator. 
Gas voltaic battery, devised by W. R. Grove, M.A., 
F.R.S., Professor of Experimental Philosophy in the London 
Institution, and described by him in a communication read 
before the Royal Society, May nth, 1843. 
A constant gas voltaic battery, also devised by W. R. 
Grove, M.A., F.R.S., and described by him in a com- 
munication to the Royal Society, dated May 30th, 1845. 
Apparatus by which Forbes produced an induction spark 
from a natural magnet. 
“ Thunder house,” or model to illustrate tbe identity of 
lightning and electricity, and the use of lightning conductors 
in protecting buildings,— said to be the first model of the 
kind, and to have been made by Dr. Priestly. 
Apparatus ereCted in the equatorial room of the Kew 
