The Microscopist: Or, A Complete Manual on the Use of the Microscope ...

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Lindsay and Blakiston, 1851 - 191 pages
 

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Page 162 - ... crystallised or uncrystallised body, or transmit it through a thin plate of either of them, it will be reflected and transmitted in the very same manner and with the same intensity, whether the surface of the body is held above or below the beam, or on the right side or left, or on any other side of it, provided that in all these cases it falls upon the surface in the same manner ; or, what amounts to the same thing, the beam of solar light has the same properties on all its sides ; and this...
Page 50 - This rule will illustrate the use of the diaphragm under the stage of the microscope. 2. Delicate observations should not be made when the fluid which lubricates the cornea of the eye is in a viscid state. 3. The best position for microscopic observations is when the observer is lying horizontally on his back. This arises from the perfect stability of the head, and from the equality of the lubricating film of fluid which covers the cornea. The worst of all positions is that in which we look downwards...
Page 102 - ... parts are separated that a correct opinion of the value of an instrument can be obtained. In selecting hair of animals for examination, the lightest coloured should be preferred. Like the scales on insects, the hair from different parts of the same individual varies considerably in structure. HAIR OF THE DERMESTES. — This very remarkable hair is obtained from the larva of a small beetle, which preys on dried animal substances, as bacon and hams. It is covered with brownish hairs, the longest...
Page 148 - TAe Earthy Salts which form the insoluble portion of the ash, and which usually amount in healthy urine to about 1 part in 1000, consist of the phosphates of lime and magnesia, together with a small trace of silica. These appear to be retained in solution in the urine by the small excess of acid (probably phosphoric) usually present, and may be precipitated from it by supersaturating with ammonia. The precipitate thus formed consists of a mixture of phosphate of lime, and the double phosphate of...
Page 36 - Huygenian eye-pieces, d, d', d", of successive powers. The erecting glasses, y, are to be screwed, when employed, into the other end of the sliding tube. They rectify the image, which is inverted when seen in the usual way. Their chief advantage is in microscopic dissection. The stage has two steady rackwork motions, at right angles to each other and to the axis of the body, given by the milledheads, e, e...
Page 109 - Swammerdam, will be abundantly gratified, whether they consider his immense labour and unremitting ardour in these pursuits, or his wonderful devotion and piety. On one hand, his genius urged him to examine the miracles of the Great Creator in his natural productions ; while, on the other, the love of that same Allperfect Being, rooted in his mind, struggled hard to persuade him that God alone, and not his creatures, was worthy of his researches, love, and attention.
Page 117 - ... to the same agencies. In short, the nucleated cell is the agent of most of the organic processes, both in the plant and animal, from the dawn of their existence to their full maturation and decline.
Page 77 - PLACE a drop of water upon a lamina of mica, and put into it of scraped chalk as much as will cover the fine point of a knife, spreading it out, and leaving it to rest a few seconds ; then withdraw the finest particles, which are suspended in the water, together with most of the water, and let the remainder become perfectly dry. Cover this remainder, so spread out, with Canadian...
Page 51 - ... in the axis of the microscope. For obscure objects, seen by transmitted light, and for outline, a full central illumination is commonly best; but for seeing delicate lines, like those on the scales of insects, it should be made to fall obliquely, and in a direction at right angles to the lines to be viewed. " The diaphragm is often of great use in modifying the light, and stopping such rays as would confuse the image (especially with low or moderate powers), but many cases occur when the effects...
Page 49 - ... excepting what is transmitted through or reflected from the object. . 2. Delicate observations should not be made when the fluid which lubricates the cornea is in a viscid state. 3. The best position for microscopical observations is when the observer is lying horizontally, on his back.

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