On the first occasion, the narrator had put poison (barium carbonate) to kill rats and mice that had got into his library. Bruno, unaware of the poison (as he was supposed to be) entered the library and ate some of it. Consequently, he got paralysed so badly that he could not even stand on his feet. As he weakened rapidly due to the effect of the poison and some vomiting, he barely managed to drag himself and floundered about on his stumps. Heavy breathing with heaving flanks and gaping mouth, his condition remained quite unstable for a while. On the second occasion, Bruno nearly drank one gallon of the old engine oil that the narrator had drained from the sump of the Studebaker and was keeping as a weapon against the inroads of termites. However, the engine oil, fortunately, did not have any detrimental effects on the sturdy bear.