Everybody has written about the Grotto del Cane and its poisonous vapors, from Pliny down to Smith, and every tourist has held a dog over its floor by the legs to test the capabilities of the place. The dog dies in a minute and a half--a chicken instantly. As a general thing, strangers who crawl in there to sleep do not get up until they are called. And then they don't either. The stranger that ventures to sleep there takes a permanent contract. I wanted to see this grotto. I resolved to take a dog and hold him myself; suffocate him a little, and time him; suffocate him some more and then finish him. We reached the grotto at about three in the afternoon, and proceeded at once to make the experiments. But now, an important difficulty presented itself. After I had taken off my coat and bathed a handkerchief with cologne, and tied it over my face, and got all ready, and was wrought up to the highest pitch of enthusiasm, I recollected that we hadn't got any dog. This toned me down some. Well, I thought the matter over, and concluded to go back to a house, about half a mile away, where I had seen a dog, and see if I could borrow it. Brown grumbled a good deal, for the day was hot, but my interest was hot, too, and we started. And so we tramped, tramped, tramped, till I thought we had walked ten miles, and at last we reached the house, almost fagged out. We sat there and chatted awhile, and dropped gently into the subject of the dog, and found that the woman who owned him was prejudiced against loaning him out to be experimented on with poisoned air. It was singular, but we had no time to discuss the foolish prejudices of "them pheasants," as Brown calls the peasantry, and so we just bought the dog, out and out, and started back. It was a long pull, and a weary one. Pull is the correct word, because the dog didn't want to come, and so we had to haul him, turn about, by a long rope he had around his neck. Sometimes that dog would sit down and brace his fore-paws, and it took both of us to start him; and when he did come he would come with a yelp, a skip and a jump, and then he would prance twenty steps to the right and twenty to the left with his paws in the air and collar half over his ears, and cavort around and carry on like a lunatic. And Brown would "rair back" on the rope and sweat and swear. He swore at me, too, for wanting to take so much trouble just to try some foolish experiments. This person has no appreciation of science.

Well, toward sunset we got the dog to the place, and I took off my coat in a fever of excitement, and rolled up my sleeves, and saturated my handkerchief again and tied it over my nose. And then--just then, after all my trouble and vexation, the dog went up and smelt Brown's breath and laid down and died.

[Daily Alta California, 6 October 1867]