379 
present an eccentric spherical cavity; this cavity, however, is 
not the true cell-cavity, but a mere vacuole in the protoplas- 
mic contents. Its size is very various; it is sometimes barely 
visible under the highest powers, while, in other instances, it 
occupies nearly the whole of the cell. By the action of iodine 
the protoplasm is turned dark-brown, and the cell-membrane 
is then rendered apparent. There is no distinct indication of 
a nucleus; and authors who have described a manifest nucleus 
have evidently mistaken for this body the vacuole, already 
described, in the protoplasm. Ifa nucleus exist, it is probably 
concealed in the thick opaque protoplasm. In some instances 
the contents of the cell appeared broken down into a multi- 
tude of detached granules ; the cell-wall was then very visible 
without the aid of iodine; this condition was probably con- 
fined to dead cells. 
In an example of “‘spent wash,” the residuum which re- 
mains after the distillation of the fermented wort, the micro- 
scope showed that the solid matter was almost exclusively 
composed of ferment-cells and Bacterium filaments; the cells 
retained their spherical figure, but their contents presented 
the granular condition just described. The filaments appeared 
unaltered. : 
Dr. Apjohn read a paper on the nature and relative pro- 
portion of the alkalies occurring in the granite of the vicinity 
of Dublin. 
A paper was read at a recent meeting of the Academy, by 
‘Sir Robert Kane, which communicated the results of some 
analyses, made under his direction, of waters from Ticknock, 
on the slope of the Dublin mountains. From this communi- 
cation it appeared, that these waters included a large amount 
of alkaline silicates, but that the proportion of potash present 
was very small compared to that of the soda, their relative 
quantities being very nearly represented by the numbers 1 
and 13. 
