- 320 New Publications. 
with a great many fine roots of fhrubs;° and near Florence 
there is a fpecits of it confifting of hardened turf, which is dug 
up mear volcanoes. The author made experiments with a! 
' piece procured from Italy, and found that 100 parts contain 
from 45 to 46 filiceous earth, 23 argillaceous earth, 7 calca~ 
reous earth, and 20 calx of iron, with fome white magnefia 
and vegetable alkali. It is well known, that when this fria-_ 
ble fpecies of ftone is preferved in cellars and moiftened with 
water, it produces abundance of eatable mufhrooms, which, 
in Italy, are highly efteemed and brought to the firft tables. 
The author confiders it more beneficial to cultivate morels 
inftead of thefe in Sweden, and gives an account of the me- 
thod.—III. On the Art of hardening Copper, by P. J. Hjelm. 
Copper, without doubt, was earlier known and employed 
than iron; and fome ancient weapons of great hardnefs have 
given rife to refearches in regard to the art of hardening it. 
The attempts, however, to harden it in the fame manner as 
fteel, all mifcarried, and the art was confidered as loft. It was 
then tried whether this object could not be accomplithed by 
mixing it with other metals. Monnet believed that arfenic 
had been ufed by the ancients for this purpofe; Geoffroy, 
iron; Mongez and Dize, tin. The laft opinion is ftrength- 
ened by the experiments of M. Hjelm, who having accu 
tately examined the blade of a dagger difcovered in the earth, 
found that it confitted of 837 copper and 16. tin, Ofa hike, 
mixture of both metals he made blades for knives, which in 
hardnefs approached very near to the former.—IV. Newand 
ittle-known »Species of Lichens, Fifth Continuation, . by 
BE. Acharius.. The author here treats of the PAy/cia foliis 
membranaceis, iubulofis, vel longitudinaliter lacunofe canali- 
. enlatis;to which belong, 1. Lichen If/landicus ; membrana- 
ceus, adfeendens, multifido-laciniatus, ciliatus, canaliculatus, 
vividi-caflancus, feutellis feffilibus planis concoloribus. This: 
fpecies, beft known of all oh account of its medicinal 
and nourifhine: qualities, grows abundantly 11 Sweden. © In 
forefts covered with mofs'it grows to the greateft fizé on the 
eytifus 
ht a oe 
