S3 
were hermetically sealed: but they remained in their original state, although 
confined for several months, whereas other crysalids of the same kind were 
changed into butterflies.” 
“ Under these circumstances there issues a noxious vapour from the cry- 
salis, when in a confined place, and this reverting back on the subject, ren¬ 
ders it dideaded, and thus destroys it, as with animals confined in stagnant 
• 55 
air. 
“■ The same thing,” continues this naturalist, “ happens to deedd. We 
know that they germinate only at a certain degree of heat, which occasions, 
an evaporation; and being confined in a small vessel, they in consequence 
reabsorb the exhalations which they had before transpired, and then become 
corrupt. Upon taking out seeds which had been so exposed, I have often 
found the surface covered by a humid pellicle.” 
If this great naturalist had carried his trials but a step further, he 
would have found that his seeds would have vegetated, and that the exclu¬ 
sion of the air alone had hindered the expansion of the living principle. 
Hence it is, upon digging deep in the ground, plants have often been 
known to appear, not before observed in that district for time immemorial. 
Morrison observes, “ That after the late prodigious conflagration of the 
city (namely, the fire of London in 1 665), the ruins being dug up, there 
grew spontaneously the Sisymbrium Irio (Broad-leaved Hedge Mudtard), 
a rare plant in those parts, but now so abundant, as to exceed the produce 
of all Europe besides.” 
Two years ago a crop of wild mustard was reaped from the banks raised 
at Hull to form a dock for the reception of shipping; and it has been often 
noticed, that a spontaneous crop of this vegetable makes its appearance, for 
two successive years, upon the banks of all drains made in Holderness. 
“ Similar appearances,” says Dr. Hunter, “ have been observed in the isle 
of Oxholme, and other low countries.” 
“ The Lobelia (Cardinal Flower),” says Linnaeus, “ six years ago, sud¬ 
denly reappeared in the Physical Gardens at Amsterdam, which had been 
lost there upwards of twenty years.” 
* The error of this supposition has been successfully refuted by modern philosophers; for since the 
discovery of the composition of the atmosphere, and its separation into oxygen, and azotic, airs, it 
has been found after animals have died in a vessel with a given quantity of air, without removing the 
supposed noxious effluvia., oxygen air being added to the vessel, animals have then lived as freely, or 
even better, than in common air. 
