1817.] Philosophical Transactions, Part If. 1816. 463 
nomena to measurement. When a plate of glass is heated red-hot, 
and cooled in the open air, or when one of its edges is placed upon 
a bar of cold iron, the same appearances are developed during the 
cooling of the glass as were exhibited in the preceding case during 
its heating ; and when the glass is cold, the structure producing the 
fringes remains permanent. 
Dr. Brewster has shown that these changes on the structure of 
glass are independent of changes in its temperature, and that they 
are analogous to the phenomena of electricity and magnetism. The 
fact of the crystalline structure given to glass by suddenly cooling 
it had been discovered by Dr, Seebeck, and published in Schweig- 
ger’s Journal, vol, xii. p. 1. L may take this opportunity of in- 
forming Dr. Brewster that my copy of this journal is not the only 
copy of it in Great Britain. There is a copy of it in the College 
Library of Edinburgh; and I know from some circumstances that 
the number in question was in the Edinburgh Library some months 
before Dr. Brewster’s paper was read to the Royal Society. 
5. Further Experiments on the Combustion of explosive Mixtures 
confined by Wire-Gauze, with some Observations on Flame. By Sir 
H. Davy. 
This paper contains a number of experiments determining the 
proper size of the meshes of the wire-gauze proper for the safe 
lamp. It contains, likewise, the first attempt to account for the 
fact that wire-gauze prevents explosions from taking place when a 
Jamp is burned in an exploding mixture. Sir H. ascribes it entirely. 
to the cooling power of the wire-gauze. From subsequent facts 
which the author has since ascertained, there is reason to believe 
that this explanation, though at first sight rather paradoxical, is the 
true one. 
6. Some Observations and Experiments made on the Torpedo of 
the Cape of Good Hope in the Year 1812. By John T. Todd, late 
Surgeon of his Majesty’s Ship Lion. 
When the Lion was at the Cape of Good Hope, torpedos were 
frequently caught by the seine, which put it in the power of Mr. 
Todd to make some observations on them. They were always small, 
never exceeding eight iuches inlength. The electrical organs were 
cylindrical, and were supplied with more nerves than any other part 
of the body. ‘The shocks were perfectly voluntary on the part of the 
animal. ‘Those animals that gave numerous shocks were soon ex~- 
hausted, and died ; while those that refused to give shocks continued 
to live much longer. When the nerves of the electric organs were 
cut, the animal lost the power of giving shocks, but the length of 
its life was not diminished. . 
7. Direct and expeditious Methods of calculating the eccentric 
from the mean Anomaly of a Planet. By the Rev. Abram Robert 
son, D.D. F.R.S. Savilian Professor of Astronomy in the University 
of Oxford, and Radcliffian Observer. 
8. Demonstration of the late Dr, Maskelyne’s Formule for find- 
ing the Longitude and Latitude of a celestial Object from its right 
