Another thing which is necessary is to entertain or amuse them in some way, otherwise they become despondent and gloomy. It is believed by those who are familiar with these apes that loneliness or solitude is a fruitful cause of death. This is especially so with the gorilla. I have a photograph of one that was kept by a trader on the coast of Africa for nearly three years. She was devoted to him, and was never content when not in his company. His business required him to make a journey of a few days to the interior. He left the gorilla at his place on the coast where she had lived up to this time. The day after he departed she became morose and fretful, and within a few days died without any apparent cause except pining. This was observed by natives and by white traders, and her death has always been ascribed to the cause assigned. She was well known to all the traders on that part of the coast, and has been regarded as one of the best specimens known. She is the only one that I have ever known to become devoted to a human being. Another important fact that is little known but very singular is, that tobacco smoke is absolutely fatal to a gorilla. Every native hunter that I met in Africa testifies that this simple thing will kill any gorilla in the forest if he is subjected to the fumes for a short time. I have reason to believe that it is true. It may not prove fatal in every instance, but it will in many. The chimpanzee is not so much affected by it, although he dislikes it, but the gorilla detests it and shows at all times his strong aversion to it. I have no doubt that this is one of the reasons that these apes always die on board the ships by which they are brought from Africa. Both of these apes are possessed, in a degree, of savage and resentful instincts. But these are much stronger in the gorilla than in the chimpanzee. He therefore requires firm and consistent treatment. This can be used without being severe or cruel, but the intellect of the gorilla must not be underrated. He studies the motives and intentions of man with a keen perception, and is seldom mistaken in his interpretation of them. He often manifests a violent dislike for certain persons, and when such is discovered to be the case the object of his dislike should not be permitted in his presence, for the result is to enrage the ape and excite his nervous nature. When they become sullen or obstinate they should not be coaxed or indulged, nor yet used with harshness. They should either be left alone for the time or diverted by a change of treatment.