Philosophical Transactions. 163 
total weight was nearly five ounces; plum-stones were found 
in their centres, while the bulk ofthe concretions consisted of 
phosphate of lime and ammoniaco-magnesian phosphate, a large 
portion of animal matter, and a fine fibrous substance derived 
from the oat, oatmeal having formed a large part of his food 
during his illness. Mr. Children concludes this paper with 
detailing the method of analysis which he pursued, and with a 
reference to some similar cases. 
4. On the Concentric Adjustment of a Triple Object-glass. By 
William Hyde Wollaston, M.D., V.P.R.S. cs 
The centring ofa triple achromatic object-glass has always 
presented considerable difficulties to practical opticians: these, 
with his usual skill and ingenuity, Dr. Wollaston succeeded 
in removing with regard to an excellent telescope in his own 
possession, by observing the relative position of the fifteen small 
images of a luminous object near the eye-glass, which are formed 
by the binary combination of the reflections of the six surfaces 
concerned, and which are seen by an eye situated beyond the 
object-glass, and assisted, if required, by a lens. When these 
images are all in the same right line, it is obvious that the 
glasses are not only well adjusted together, but that each is 
well centred; and by means of four screws acting on each 
glass, Dr. Wollaston was able to make the adjustment so com- 
plete as considerably to improve the powers of the instrument. 
An illustrative plate is annexed to this paper. 
5. On a new species of Rhinoceros, found in the interior of Africa, 
the Skull of which bears a close resemblance to that found in a 
fossil state in Siberia and other countries. By Sir Everard 
Home, Bart., V.P.R.S. 
It has been hitherto asserted, (says Sir Everard) as one of the most curi- 
ous circumstances in the history of the earth, that all the bones that are found 
in a fossil state, differ from those belonging to animals now in existence : 
and I believe that this is generally admitted, and that there is no fact upon 
record, by which it has been absolutely contradicted ; but the observations 
I am about to state respecting this rhinoceros, illustrated by the drawings 
pew accompany them, will go a great way to stagger our belief upon this 
subject. 
The skull of this rhinoceros was brought to England by Mr. 
Campbell, who shot the animal about 250 or 303 miles, up from 
the westward of De la Goa Bay, six miles west of thecity Mashow, and 
above 1000 miles in nearly a straight direction from the Cape of Good Hope. 
The country from whence the rhinoceros comes, contains no thick woods, 
or forests, but is covered with separate clumps of trees, like a nobleman’s 
park in England. Ju travelling, yon always appear to be approaching a 
wood; but as you advance, the trees are discovered to stand at a distance 
from one another, or rather in little clumps. 
This animal feeds upon grass and bushes; is not carnivorous, and not 
gregarious ; seldom more than a pair are seen together, or in the vicinity 
of one another. Mr. Campbell’s people wounded another of the sare 
VoL. XIV. 
