Page:Popular Science Monthly Volume 27.djvu/559
MEASURES OF VITAL TENACITY.
factured in several qualities, the higher grades of which are eminently suitable for casting purposes, have a close, steel-like surface, are susceptible of a high polish, are hard and tough, and possess great tensile strength.
By Dr. B. W. RICHARDSON, F.R.S.
IN the observations which I have made on animals passing into death by the lethal process, nothing has impressed me more than the curious differences of vitality or vital values of different animals. The differences are so great they seem almost inexplicable, and in many respects they are so. To some extent, however, they come under law, and we may therefore hope that by carefully continued research what is now difficult and involved may be rendered, in time, simple and perfectly clear.
The first series of observed facts relate to vital differences in animals of different species. In illustration I may take the cat and the dog. Between these animals the distinction of vitality exists irrespectively of age, and of all other conditions and circumstances of which I can gather information.
Of the cat it is commonly said that it has nine lives. By this saying nothing very definite is meant beyond the opinion that under various kinds of death the cat lives much longer than other animals that have to be killed by violent means. When any question is asked of the police or of other persons who have to take the lives of lower animals, they tell you, without exception, according to my experience, that the cat is the most difficult to destroy of all domestic animals, and that it endures accidental blows and falls with an impunity that is quite a distinguishing characteristic.
The general impression conveyed in these views is strictly correct up to a certain and well-marked degree. By the lethal death, the value of the life of the cat is found to be, at the least, three times the worth of the dog. In all the cases I have seen in which the exactest comparisons were made, the cat outlived the dog. A cat and dog of the same ages being placed in a lethal chamber, the cat may, with perfect certainty, be predicted to outlive the dog. The lethal chamber being large enough to hold both the cat and the dog, the vapor inhaled by the animals being the same, with every other condition identical, this result, as an experimental truth, may be accepted with-out cavil.
The differences, always well marked, are sometimes much longer than would be credible in the absence of the evidence. I have once seen a cat, falling asleep in a lethal chamber in the same period as a dog, remain breathing, literally, nine times longer, for the dog died