Miscellaneous. 30 1 
he had seen the true Mygale avicularia alive in England, washed ashore from a 
wreck on the coast of Essex. , 
Mr Rootsey gave a detailed account of his experiments upon the root of Man- 
gel- Wurtzel, made for the purpose of ascertaining the probability of its being 
successfully employed in this country for the manufacture of sugar. He exhi- 
bited specimens of this sugar of good quality, and considered that a judicious se- 
lection of the soil in which the mangel-wurtzel was to be grown might certain- 
ly render it an advantageous speculation. His opinion was founded upon the 
uses to which the refuse of this plant might be applied, after extracting of the 
juice from which the sugar had been obtained. Of this refute an excellent kind 
of malt might be prepared, from which he had brewed good beer, and extracted 
an ardent spirit. It was also found serviceable for fattening cattle. He stated, 
contrary to the received opinion, that this plant was liable to the attacks of in- 
sects, as he had found it infested by the Haltica nemorum. 
Mr G. Webb Hall, as a practical agriculturist, entirely differed from Mr Root- 
sey in supposing that the mangel-wurtzel might be grown to advantage for the 
purpose of making sugar. 
Professor Henslow exhibited some crystals of white sugar- candy, obtained 
from the flowers of Rhododendron Ponticum. A detailed account of these has 
since appeared in Loudon's Magazine of Natural History for September 1836. 
Mr G. Webb Hall read a paper " on the Acceleration of the Growth of Wheat." 
By a judicious selection of seed, and a proper choice of situation, Mr Hall had 
been able to procure a ripe crop in the middle of August from seed sown early 
in March. Dr Richardson referred to a remark of Humboldt, that the Ameri- 
can crops generally were ripened in ninety days from the period when they were 
sown ; and suggested the propriety of procuring seed from Hudson's Bay, where 
he had found the crop to ripen in seventy days. 
A mode of accelerating the germination of seeds was noticed by Professor 
Henslow, who stated, that he had produced this effect by boiling the seeds of a 
Cape Acacia. The details of this experiment are given in Loudon's Magazine 
of Natural History for September 1836. Mr Hope referred to a custom in 
Spain of partially roasting the corn before sowing it, for the purpose of destroy- 
ing an insect by which it was infested. 
Dr Daubeny stated, that he had commenced a series of experiments for the 
purpose of ascertaining the effects produced by arsenic on vegetation. He had 
been informed that nothing but a few Leguminosse would grow in a particular 
district of Cornwall, where the soil contained about 50 per cent, of the sulphu- 
ret of arsenic, and the rest of which was chiefly sulphuret of iron and silica. 
He had ascertained that a little of the sulphuret of arsenic produced no effect on 
vegetation, probably from its not being very soluble, though it was certainly 
taken up in a certain proportion. He had also ascertained that plants would 
bear being watered with a solution of arsenious acid, in much greater proportion 
than was hitherto considered possible, without injuring them. 
Tuesday, August 23c? Dr Richardson's Report continued. 
Mr Bowman read a communication on the Longevity of the Yew Tree. He had 
examined several young trees whose precise ages were known, and had ascer- 
tained that their average rate of increase for the fiist 120 years was at least two 
lines, or the sixth of an inch per annum. He then proceeded to give his mode 
of estimating the ages of two very large trees, from the trunks of which he had 
4 
