NATURAL SCIENCES OF PHILADELPHIA. 
119 
pipes, made its way beneath, the eastern foundation wall of the greenhouse of 
B. A, Fahnestock, on the southwest corner of Arch and Eighteenth Streets.* 
When entering the houses on the morning of the first of February, the odor 
of gas was perceptible, which, on examination, was found issuing in a tolera- 
bly strong current through the ground near the north eastern corner of the 
greenhouse. It came up through a prepared border of soil between the wall 
of the house, and the flagging of the greenhouse floor. Although somewhat 
relieved by ventilation during the day, it was impossible to prevent its accumu- 
lation through the night ; and by the following morning the work of destruc- 
tion was accomplished. A choice and beautiful collection, numbering over 
three thousand plants, was, for the time being, almost utterly ruined. Many 
of the specimen plants were unique, and but rarely found in American collec- 
tions. The house, which a day or two before had given promise of an abundant 
succession of winter flowers, now presented the desolate appearance of tender 
vegetation after a severe frost. In some parts of the premises, scarcely a single 
plant retained a leaf or bud. By the universal difi"u3ion of this gas through 
the houses, many of the severest sufierers were those farthest removed from 
the point of its ingress. 
That the plants had been absorbing carburetted hydrogen for some time was 
evident from the fact, hitherto unaccountable to the gardener and ourselves, that 
they had been occasionally shedding buds and leaves. Had there been no 
plants in the house, the peculiar odor of gas would doubtless have been per- 
ceptible for some days before the accident. Its volume proved to be much 
greater than we at first supposed. Those plants placed upon or near the floor, 
or upon the lower tiers of staging, sufiered less than the taller specimens, or 
than such as were near the upper sash. This was especially the case with 
the Camellias, and other hardwooded plants. 
The full extent of the damage was not apparent at first. Many plants main- 
tained their fresh greenness without b'^coming shrivelled, or withering ; yet 
although seemingly in fine health, they shed every leaf at the slightest touch. 
Syringing was resorted to with the hope that the absorption of water might, 
in some degree, counteract, or neutralize the noxious effects of the gas ; but in 
most instances, the leaves and buds fell off when treated with gentle streams 
of water from a finely perforated syringe. 
As no plant sufi'ered unless in leaf at the time, it seems evident that the 
injury was eff"ected and sustained by absorption through the medium of the 
foliage alone. The volume of gas was too small to be absorbed to any extent 
by the earth, or roots of the plants. Bulbs, and other plants, dry and at rest, 
were distributed in considerable number through the houses, both upon the 
upper shelves and beneath the staging. 
A row of grape vines (not in leaf) stood against the eastern wall within the 
greenhouse, growing in a prepared border of earth under the table. The 
gaseous current passed directly through their roots. Saturated as the ground 
seems to have been with fresh gas, which was strongly manifest on taking up 
a handful of the earth, they do not appear to have sustained any injury there- 
by. A row of maple trees along the outer edge of the footwalk on Eighteenth 
street were also directly in the way of the current. They were not more than 
eight feet from the leaking pipes. Owing to the depth of frost it is probable 
that the flow of gas passed beneath their roots ; nevertheless the ground within 
a few feet was black with the " dead gas.'''' They sustained no apparent injury, 
* In order to convey as correct an idea as possible of the relative positions of theplaats 
v/ithin the houses, it may be proper to observe briefly that the greenhouse is one hundred 
feet iE length by twenty-five in breadth, runs north and south, and is substantially con- 
structed of brick, with a span roof of sash. The western side is also of glass from within 
tour feet of the ground. The span commences about eight feet from the floor, with the 
apex about seventeen feet in height. Included within the same range is the hot house, 
separated from the greenhouse by a sash partition, and communicating by two sash doors 
At the extreme end, farthest from the leak, a small orchid house opens into the hot-house, 
1858.] 
