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THE POPULAR SCIENCE MONTHLY. 



cisely similar, except as to the local topography, is related in 

 Chambers's Journal, of a cat in a military chaplain's family at 

 Madras. This animal also, having found its old friends on the 

 other side of the city, several miles from their former home, 

 went back and brought her kitten. Some of the incidents bear- 

 ing upon this feature have an aspect of eccentricity. The young 

 cat of a neighbor of the writer's disappeared from the house 

 and was not found or heard of for six months. At the end of that 

 time it returned and made itself at home at once, but grown 

 and so changed that, though its familiarity was remarked upon as 

 singular, it was not recognized till its identity was accidentally 

 established by the discovery of a peculiar though obscure mark. 

 Dr. A. Corriveau tells in the Revue Scientifique of a cat which was 

 lost in a similar way. Five months afterward it was found in 

 the house by the side of its companion, travel-soiled but plump, 

 and recognizable by a red spot on its forehead. It had a very 

 pleasant visit with its old mate and friends for a week, and then 

 disappeared as unaccountably as it had done before. It is told in 

 the Life of Sir David Brewster, by his daughter, that a cat in the 

 house entered his room one day and made his friendship in the 

 most affectionate manner — "looked straight at him, jumped on 

 his knee, put a paw on each shoulder, and kissed him as distinctly 

 as a cat could." From that time the philosopher himself provided 

 her breakfast every morning from his own plate, till " one day she 

 disappeared, to the unbounded sorrow of her master. Nothing was 

 heard of her for nearly two years, when Pussy walked into the house, 

 neither hungry nor thirsty nor foot-sore — made her way without 

 hesitation to the study — jumped on my father's knee — placed a paw 

 on each shoulder — and kissed him exactly as on the first day." 



These incidents pertain to only one of the human-like traits 

 that have been named as to be found in cats. The study to which 

 they introduce us is an alluring one, and opens the more expan- 

 sively the further we proceed in it. 



Prof. Mendelejeff, in his Royal Institution lecture, found an analogy between 

 the unseen world of chemical changes and the visible world of the heavenly bodies. 

 Our atoms, he said, form distinct portions of an invisible world, as planets, sat- 

 ellites, and comets form distinct portions of the astronomer's universe; "our 

 atoms may therefore be compared to the solar system, or to the systems of double 

 or of single stars ; for example, ammonia may be represented in the simplest man- 

 ner by supposing the sun nitrogen, surrounded by its planets of hydrogen, and 

 common salt may be looked upon as a double star formed of sodium and chlorine. 

 Besides, now that the indestructibility of the elements has been acknowledged, 

 chemical changes can not otherwise be explained than as changes of motion; and 

 the production by chemical reactions of galvanic currents, of light, of heat, of 

 pressure, or of steam-power, demonstrates visibly that the processes of chemical 

 reaction are inevitably connected with enormous though unseen displacements, 

 originating in the movements of atoms in molecules." 



