Conversations on Natural Philosophy

Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: Emily. It requires an effort beyond my strength, though there are handles for the purpose of pulling thera asunder. Is the firm adhesion of the two hemispheres, merely owing to the attraction of cohesion ? Mrs. B. There is no force more powerful, since it is by this that the particles of the hardest bodies...
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Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: Emily. It requires an effort beyond my strength, though there are handles for the purpose of pulling thera asunder. Is the firm adhesion of the two hemispheres, merely owing to the attraction of cohesion ? Mrs. B. There is no force more powerful, since it is by this that the particles of the hardest bodies are held together. It would require a weight of several pounds, to separate these hemispheres. Emily. In making a kaleidoscope, I recollect that the two plates of glass, which were to serve as mirrors, stuck so fast together, that I imagined some of the gum I had beon using had by chance been interposed between them; but .low I make no doubt but that it was their own natural cohesive attraction which produce.l this effect. Mrs. B. Very probably it was so; for plate-glass has an extremely smooth, flat surface, admitting of the contact of a great number of particles, between two plates, laid one over the other. Emily. But, Mrs. B. the cohesive a'traction of some bodies is much greater than that of others; thus, glue, gum, and paste, cohere with singular tenacity. Mrs. B. That is owing to the peculiar chemical properties of those bodies, independently of their cohesive attraction. There are some other kinds of modifications of attraction peculiar to certain bodies; namely, that of magnetism, and of electricity; but we shall confine our attention merely to the attraction of cohesion and of gravity; the examination of the latter we shall resume at our next meeting. CONVERSATION II. ON THE ATTRACTION OP GRAVITY. Attraction of Gravitation, continued; Of Weight; Of the Fall of Bodies; Of the Resistance of the Air; Of the Ascent of Light Bodies. Emily. I Have related to my sister Caroline all that you have aught me of natural philosophy, and she ha...