38 REPORT—1843. 
Chemical Suggestions on the Agriculture of Cork. 
By Tuomas JENNINGS. 
The author drew attention to the present state of agriculture in the south of Ire- 
land, and to the immense importance of some system by which the yalue of the lime- 
stones and sands of the district might be carefully ascertained by good chemical ana- 
lysis. Two kinds of limestone were found in the neighbourhood of Cork ; the variety 
which yielded the best lime for building was found to be very inferior to the other as 
amanure. The sands from the bed of the river Lee, and many of the sea sands were 
used as manure with very uncertain results. The author suggested the propriety of 
having correct analyses made, and large masses of the rock, or of the sand, placed in 
some museum, where the results of careful analysis should be registered. 
On the Minerals of Cork. By R. W. Townsenv. 
A series of minerals, all of them collected by Mr, Townsend, was exhibited. This 
collection included some beautiful specimens of copper pyrites, gray copper, and ma- 
lachite, manganese ores of a fine character, and some rare iron ores, and may be re- 
garded as giving a fair view of the mineralogical condition of the county. 
Mr. Townsend also exhibited a specimen of manganese taken from the deposit 
formed by a thermal spring near the Cape of Good Hope. The water issued at a 
temperature of 110°, and so large was the quantity of manganese, which, in some 
form, it held in solution, that a very thick incrustation lined the stream within a short 
distance of the spring. 

On newly-discovered Three-twin Crystals of Harmotome, so arranged that 
they form a regular Rhombic Dodecahedron. By Dr. F. TAmyau of Berlin. 
The celebrated Mohs was the first who observed that the modification of the pri- 
mary form of harmotome was such as could never belong to the pyramidical system, 
in which it was placed by Werner and his disciples. Messrs. Phillips and Brooke 
gave measurements of the mineral, and confirmed the idea of Mohs. During a resi- 
dence in Paris Dr. Tamnau met with a very beautiful three-twin crystal of harme- 
tome, and also in Bohemia, in a basaltic rock in the neighbourhood of Aussig, on the 
bank of the river Elbe, It was accompanied with small crystals of analcime—little 
white crystals of chabasite,—and some yellow-brown crystals of carbonate of lime, 
which specimens were exhibited. Each of these little groups of erystals consists of 
three single crystals, so arranged that the axes cross each other at angles of 90°. 
By this arrangement the faces of the pyramid on the one crystal falls exactly together 
with the faces of the same pyramid of the other crystal ; and if those faces were en- 
larged so much, that the faces of the prism should not be visible, they would give the 
form of a regular rhombic dodecahedron. Not only are the angles of the pyramid 
exactly determined independent of any single measurement, but it is also decided that 
the two angles of the pyramid are of the same value, and consequently that the mi- 
neral is not in its primary form of the right rectangular, but that it is a right square 
four-sided prism. And it may at the same time be observed that, however the dis- 
tribution of the secondary faces may show the harmotome to belong to the prismatic 
system, we have in it a remarkable instance of a mineral which is pyramidical in its 
mathematical measurement, and at the same time prismatic in its physical qualities. 
ome ee 
Dr. Tamnau, of Berlin, exhibited some rare mineralogical specimens :—1. A group 
of Datholith, from the neighbourhood of Andreasberg, in the Hartz. 2. Two speci- 
mens of rose-coloured Harmotome, from Andreasberg. The colour of these speci- 
mens was attributed to the presence of a small quantity of cobalt. They were re- 
markable for the great size of their crystals, which exhibited not only the usual twins, 
but also curious and complicated arrangements of three and four, combined according 
to laws not yet sufficiently understood to allow of their being clearly described. 
3. Two very large isolated crystals of Beryl, from Royalstone, Massachusetts. These 
were of a beautiful sea-green colour, one of them of the usual form, a regular six-sided 

