Proceedings of the Ca mbridge Philosophical Societij. 
ceived from Dr Brewster, in which he states, that he has exa- 
mined with great care a specimen of Leelite, and found it to be 
an irregularly crystallised body resembling horn stone, flint,^ &c. 
and having a sort of quaquaversus structure, or one in which 
the axes of the elementary particles are in every possible direc-* 
tion. The alumina which leelite contains, gives it quite a dif^ 
ferent action upon light from any of the analogous siliceous sub- 
stances, and thus an optical character is obtained, by which it 
may be distinguished with the greatest facility, 
A paper was read by J. Okes, Esq. on a peculiar case of the 
enlargement of the Ureters in a boy. 
After detailing the symptoms of the case during life, from 
which no satisfactory inference could be drawn respecting the 
nature of the disease, Mr Okes described the appearance upon 
dissection- ' The bladder was healthy, but the orifices of the 
ureters unusually large, and so formed as to allow the free in- 
gress and egress of urine through them. The calibre of these 
tubes was in some parts larger than the rectum, and formed 
convolutions not very dissimilar to those of the intestines. From 
all the circumstances of the case, which were traced back to the 
child’s infancy, Mr Okes is induced to attribute the dilatation 
of the ureters, and destruction of the kidneys, to an original 
malformation of the vesical end of the ureters, and shews the 
improbability of its having been caused by the passage of cal- 
culi through them. 
Nov. 26. — Notice of an instance of fossil bones found on the 
road between Streatham and Wilburton, in the Isle of Ely, by 
Dr F. Thackeray. 
A communication, by the Reverend William Mandell, B. D.' 
of Queen’s College, on an improvement on the common modq 
of procuring potassium. In the common process, a consider- 
able inconvenience arises from the lute cracking and consequent 
fusion of the gun-barrel, which contains the materials. Mr 
Mandell prevents this accident, by enclosing the barrel in a 
tube of well burnt Stourbridge clay, whose diameter is rather 
larger than that of the barrel. 
A paper by William Whewell, Esq. M. A., Fellow of Tri- 
nity, On the Crystallisation of Fluor SparC 
B b 2 
