I might refer you to legends, of which I can scarcely press for your belief. As the strange but authenticated story of Anna Garbero, of Racconiggi, forty miles from Turin, who existed without nutrition for two years, becoming like a shrivelled mummy. And that of Eve Hergen, who existed thirteen years upon the odour of flowers! But even with that incredulous frown of Astrophel’s, and that faint smile of thine, fair Castaly, let me at once to my explanations.
In natural sleep the functions of the body are impeded. One of these is digestion. As there is little waste of the system there is little necessity for repletion, and life can be supported by a very slight action of the heart, a minute current of blood; like the slender vitality of infants, who, even in a state of health, seem frequently scarcely to breathe. The circulation is materially influenced in sleep, the pulse being slower and more feeble than during waking; the relaxation of the cutaneous vessels inducing frequent perspiration, especially in debilitated systems, and in the last stages of adynamic fevers.
The body of the cataleptic patient descends to the condition of less complex animal life, in which there appears a much greater simplicity of organization; and we well know, as we descend in the scale of creation, towards the cold-blooded single-hearted animals, and especially if we reach the zoophyte, in how exact a proportion to this simplicity of structure is the tenacity of life increased. “Fish,” says Sir John Franklin, “were taken out of the nets frozen, and became a solid mass of ice, being by a blow of a hatchet easily split open; they, however, recovered their vitality on being thawed.”
A course of systematic abstinence will enable us, if we wished it, to endure extreme privations, which a high feeder would soon sink under; and this is probably the discipline adopted by the fakirs of India, who fast so long under the influence of superstitious devotion.
Vaillant’s spider lived without food nearly one year; John Hunter’s toad fourteen months; land tortoises eighteen months; a beetle three years; and two serpents, according to Shaw, five years; an antelope has survived twenty days without food; some dogs forty days; an eagle 23 days.
Now all animals fall asleep at certain temperatures, which they cannot resist, but the common effect of extreme cold is death. Dr. Solander was yielding to the influence of intense cold in Terra del Fuego, but was saved by the firmness of Sir Joseph Banks. Richmond, the black, lay down on the snow to sleep, and died.
There is a close analogy between this state and the hybernation of animals, although the causes are not similar. Animalculæ often become torpid for lack of moisture, and, even after the lapse of twenty-seven years, have been revivified by water. The small furcularia anastobea will repeatedly become animated and lively by a single drop of water, its previous condition being completely quiescent. The snail, the alligator, indeed most of the ophidian and saurian reptiles, assume the torpid state in a period of extreme drought; and Humboldt states this also of the centenes solosus, a Madagascar hedgehog.
This hybernation of animals, as of the marmot and the dormouse, resembles the deep sleep arising from cold of a certain degree; for if this be intense, they will sometimes be momentarily roused from it. They may be constantly kept awake by heat and powerful light.
Thus hybernation and the sleep of plants take place from the withdrawal of stimuli; heat being the animal—light the vegetable stimulus.
Cast. The sleep of plants? a fiction surely!