The Poor Dog at the Grotta del Cane.
Henry Matthews,[82] like other visitors of Naples, went to the celebrated Grotta del Cane, or Dog Grotto, on the borders of Lake Agnano, so called from the vapour in the cave, destructive to animal life, being shown by means of a dog. In his diary, of March 3, 1818, he records:—"Travellers have made a great display of sensibility in their strictures upon the spectacle exhibited here; but to all appearance the dog did not care much about it. It may be said, with truth of him, that he is used to it; for he dies many times a day, and he went to the place of execution wagging his tail. He became insensible in two minutes; but upon being laid on the grass, he revived from his trance in a few seconds, without the process of immersion in the lake, which is generally mentioned as necessary to his recovery. From the voracity with which he bolted down a loaf of bread which I bought for him, the vapour does not seem to injure the animal functions. Addison seems to have been very particular in his experiments upon the vapour of this cavern. He found that a pistol would not take fire in it; but upon laying a train of gunpowder, and igniting it beyond the sphere of the vapour, he found that it could not intercept the train of fire when it had once begun flashing, nor hinder it from running to the very end. He subjected a dog to a second trial in order to ascertain whether he was longer in expiring the first than the second time; and he found there was no sensible difference. A viper bore it nine minutes the first time he put it in, and ten minutes the second; and he attributes the prolonged duration of the second trial to the large provision of air that the viper laid in after his first death, upon which stock he supposes it to have existed a minute longer the second time."