British Association for the Advancement of Science. 13 
The Rev. J. Yates read a paper on the same subject. Wish- 
ing, he observed, to make an experiment, on a large scale, which 
might be exhibited at the meeting of the British Association in 
Liverpool, a green-house, nine feet by eighteen in dimensions, 
and with a southern aspect, had been erected in the yard of the 
Mechanics’ Institute, in Mount-street. It was stocked with for- 
eign plants of all kinds, to the number of about eighty species. 
A list of the plants, and observations on their condition and pro- 
gress, accompanied the report. The general result of the exper- 
iment was, that the plants had flourished perfectly well, being in 
a vigorous and healthy state, without any extraordinary growth. 
Many of them had flowered, and Canna and some Ferns had ri- 
pened seed. The green-house had no flue, and no provision for 
any artificial heat. It was judged best to construct it without a 
flue, both as least expensive, and for the purpose of trying, by a 
fair experiment, to what extent plants might in this state be kept 
alive, even during the severity of winter, which would certainly 
die if fresh air were more freely admitted. It was also to be ob- 
served, that nothing had been done to prevent the water from es- 
caping through the yellow sandstone rock, on which the green- 
house was erected, and hence it had been necessary to give the 
plants occasionally a fresh supply of water. Mr. Yates further 
stated, that he had also grown plants under glass in London, where 
no plant could be made to flourish without such a protection. 
Nearly a year ago he planted Lycopodium denticulatum in a chem- 
ical preparation glass, with a ground stopper. During that time 
the bottle has never been opened ; yet the Lycopodium continues 
perfectly healthy, and has grown very much, although, for want 
of space, the form of the plant is distorted. Seeds which hap- 
pened to be in the soil have germinated, and Marchantia has 
grown of itself within the glass. He also obtained a hollow glass 
globe of eighteen inches diameter, and with an aperture sufficient 
to admit the hand for planting the specimens. A variety of Ferns 
and Lycopodiums were then set in the soil, which was properly 
moistened with water. This having been done, the aperture was 
covered with sheet India-rubber, its attachment to the glass being 
made perfectly air-tight. Nochange of air could take place, except 
by percolation through the India-rubber, which was every day 
forced either outwards, as the air within the glass was heated and 
expanded, or inwards in the reverse circumstance ; these Ferns 
