INDEX 
TO THE 
PHILOSOPHICAL TRANSACTIONS 
FOR THE YEAR 1820. 
A page 
Alburnum , upon the different qualities of the alburnum 
of spring and winter-felled oak-trees - - 156 
Aneurismal tumor, a description of a deposit of crystals 
found in one, - - 3 
Apophyllite, of its anomalous tints, - - 76 
the only crystal with one axis, whose tints 
exhibit a sensible deviation from the scale of Newton, 91 
- its tints commence at the centre of the rings 
and increase in regular progression outwards, - 91 
Astronomical observations, - 330 
B 
Bakerian Lecture , by William Thomas Brande, Esq. Sec. 
R. S. - - - 11 
Barometer , thennometrical, a description of some improve- 
ments made in this instrument, - - 303 
Bauer, Francis, Esq. Some experiments on the fungi 
which constitute the colouring matter of the red snow 
discovered in Baffin’s Bay, - - 165 
Blood , a farther investigation of its component par-ts, 1 
an experiment to ascertain whether the proportion 
of aeriform matter in the blood is liable to vary, - 6 
- coagula of, examination of those formed in aneu- 
rismal tumors, - - - 2 
I 
