150 
TUMOUR WITHIN THE CRANIUM. 
The composition of this substance, as given by chemists, is 
C 36 H 30 O. It occurs in the form of white pearly scales, 
which are lighter than water; soluble in boiling alcohol and 
in ether, also in wood-spirit and oils ; but it resists being 
saponified by the alkalies, which is its characteristic* 
In another part of this journal will be found an interesting 
discussion that has recently taken place on this subject in 
the " Societe Imperiale et Centrale de Medecine Veterinaire ” 
of France. And we append to this the description of a very un- 
usual instance of a crystal of oxalate of lime, contained within 
a cyst situated upon the olfactory nerve of a horse ; which 
was communicated to the Microscopical Society of London 
by Mr. J. B. Simonds. He observes that — 
"The recent publication of Mr. Quekett’s lectures on the 
occurrence of earthy salts in both animal and vegetable cells 
gives an unusual interest to these depositions, and more 
especially when they are met with in those parts of the 
organism of animals where we should scarcely anticipate their 
presence. For this reason, and as an addendum to his valuable 
papers now being read before the Society, I am induced to 
bring before you an interesting and novel fact which has 
lately come to my knowledge relating to a deposit of the 
oxalate of lime within a cell or small membranous cyst. 
" In the latter part of March, Mr. Boreham, then a pupil 
of the Royal Veterinary College, found, in dissecting the brain 
of a horse which had been procured from the slaughter-house, 
a small transparent cyst, possessing a very bright or glistening 
aspect, attached to the bulbous portion of the right olfactory 
nerve. The specimen, together with a small portion of the 
nerve, was carefully removed, and a day or two afterwards it 
was kindly presented to me, he at that time believing it to be 
an hydatid. 
" From having been kept in water, I found that the nerve 
was somewhat decomposed, and very readily separated into a 
pulpy mass ; a circumstance which prevented any minute 
examination of its structure being made. I observed, how- 
ever, that its substance was partly absorbed, so as to form a 
cup-like concavity for the lodgment of the cyst ; and I am 
led to infer from this circumstance that the sense of smell of 
the animal was greatly interfered with, and probably rendered 
very obtuse. But of this, as well as the existence or other- 
wise of pain from the pressure of the cyst, we are without 
means of ascertaining. 
"On placing the specimen under the microscope, and 
viewing it with a two-inch object-glass, I was surprised to 
find a large octohedral crystal of oxalate of lime, with beauti- 
