vi CONTENT S. 
and A. S. and Member of the Academy of Sciences and 
Belles Lettres at Lyon. p. 362 
XXVI. Account of a new Kind of inflammable Air or Gafs, 
which can be. made in- a Moment without Apparatus , and 
is as fit for Explofion as other inflammable Gaffes in ufe 
for that Furpofe ; together with a nezv fib eery of Gun- 
powder. By John Ingen Houfz, Body Phyjician to their 
Imperial Majeflies and F. R. S. P-376 
XXVII. The Defcription of Two new Micrometers. By 
Mr. Ramfden, Optician ; communicated by Jofeph 
Banks, Efq. P. R. S.. p. 419 
XXVIII. Account of the Airs extracted from different 
Kinds of Waters ; with ‘Thoughts on the Salubrity of 
Air at different Places. In a Letter from the Abbe 
Fontana, DireBor of the ■ Cabinet of Natural Hiflory be- 
longing to his Royal Highnefs the Grand Luke of Tuf- 
cany, to Jofeph Prieftley, LL.D. F. R. S. p. 432 
XXIX. Account of fome Experiments in EleBricity. In a 
Leter from Mr. William Swift to the Rev. Dr. King, 
F. R. S. p. 454 
XXX. Skodium incifum et macrocarpon , ufufque fruc- 
tuum qui exinde nafeuntur, deferipta a Carolo Petro 
Thunberg, M. Dr, communicated by Jofeph Banks, 
Efq. P. R. S. p. 462 
XXXI. A Second Paper concerning fame Barometrical 
Meafures in the Mines of the Hartz. By Mr. John An- 
drew De Luc, F. R. S. p. 485 
XXXII. On the Preceffion of the Equinoxes produced by 
the Sun's AttraBion. By the Rev. Mr. Ifaac Milner, 
M. A. 
