MM. Pebal and Mayer on Cobaltie Acid. 51 
_ From the fact, that the felspathic trap of Benaunmore occurs 
in columnar masses, it may be inferred to be probably of igneous 
origin ; it is massive, fine-grained, with rounded specks of quartz 
(globuliferous), and small occasional facets of felspar ; brittle, of 
conchoidal fracture, somewhat lamellar, and translucent on the 
edges ; with a ringing clink and striking fire freely when struck 
with the hammer. 
I have lately had an opportunity, in conjunction with Dr. 
Wilde of Dublin, of examining a very large number of stone 
implements found in various parts of Ireland ; and I find that 
the different varieties of siliceo-felspathic rocks were carefully 
sought out by the makers of these implements. Among the 
most common varieties so used, are the pure pale-green felstone, 
and a mottled porphyritic variety of the same kind of rock, 
streaked with pink felspar and dark-coloured metallic hornblende. 
In the collection of stone implements preserved in the Col- 
lection of the Royal Irish Academy, there are also a number of 
stone implements from Jamaica, formed of the same kind of 
felstone, which would appear to have been particularly well suited 
to the purposes to which such implements are supposed to have 
been applied. 
The felstones and siliceo-felspathic rocks of Ireland are only 
locally abundant, and as the weapons made from this kind of 
rock are found in all parts of Ireland, it is conjectured by anti- 
quarians that an extensive trade in, and manufacture of, these 
felstone celts and weapons must have existed in former times in 
Treland. This trade, if such existed, must have been confined 
to Ireland itself, as there is scarcely a single stone implement in 
the Collection of the Irish Academy which cannot be readily 
identified as made of an Irish rock ; and’in many instances the 
locality from which it was obtained can be assigned with tolerable 
accuracy. 
VI. Chemical Notices from Foreign Journals. 
By #. Arxinson, PA.D. 
[Continued from vol. xiii. p. 506.] 
Y the action of hydrate of potash on oxide of cobalt at high 
temperatures in contact with the air, Schwarzenberg * ob- 
tained a brown fused mags, which on treatment with water leaves 
a quantity of black, lustrous, soft crystals of hexagonal and other 
rhombic forms. These crystals contain cobalt, oxygen, potash 
and water, and Schwarzenberg held that they were a compound 
of a new oxide of cobalt, which he named cobaltie acid, with 
potash and water in definite quantities; that the potash and 
* Liebig’s Annalen, vol. xevii. p. 211. 
E2 
