m 
Saien tific In telligenee. 
what was very singular, the luminous patches were constantly 
in a , tremulous or undulating motion during the intervals of the 
flashes of lightning. They shifted their place, and changed 
their form, exactly like the light which appears in many of the 
varieties of the aurora borealis. As the luminous clouds now 
described, did not appear in the northern part of the horizon, 
and were distinctly related, in their position and form, to the 
thunder-cloud from which the lightning emanated, we are en- 
titled to refer the two cjasses of phenornena to the peculiar electri- 
cal condition of the atmosphere, and to suppose that the phenome- 
na of the aurora borealis may have an analogous origin, B. 
5. Dr Wollaston the Inventor of the Mthriosccrpe.-r-^YI q have 
received from our ingenious correspondent, Mr Murray, the de- 
scription of a new JEthrioscope of his own invention, which we 
intended to have printed in this Number, As the introductory 
part, however, contains repeated reference to Mr Leslie as the 
inventor of that instrument, we deem it necessary to make the 
following claim to that invention, in behalf of our distinguish- 
ed countryman Dr Wollaston, as an apology, both to our readers 
and to Mr Murray, for questioning the accuracy of the histori- 
cal part of his paper. 
Before the publication of the late Dr Wells’s ingenious work 
on Dew, which appeared in 1814, Dr Wollaston exposed a 
concave metallic mirror^ turned uptvards to the free air, with a 
thermometer placed in its focus, and proved the lowering of its 
temperature after a short time of' its being thus exposed!^'' At 
what time Dr Wollaston made this elegant experiment, we do 
not know, but he communicated it to M. Biot, who publish- 
ed an account of it in the Bulletin des Sciences par la So- 
ciete Philomathique, for November 1816, in a paper entitled, 
Sur la Deperdition de Calorique, qil occasionne le Rayonnement 
des Corps vers les del. A short abstract of the above paper 
of M. Biot was published on the 1.9^ April 1817, in Mr Brande’s 
Journal, Vol. III. p. 184. and this abstract contains the above 
paragraph which we have quoted in Italics. 
Mr Leslie’s paper on the aethrioscope was read to the Royal 
Society of Edinburgh on the 16th March 1818, and he himself 
states *, that it was invented by him after October 1817. This 
* Edinburgh Transactions, Vol. VIII. p. 484, 485. 
