The Microscopist's Companion; a Popular Manual of Practical Microscopy: To which is Added a Glossary of the Principal Terms Used in Microscopic Science |
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Common terms and phrases
acetic acid achromatic albumen alcohol Algæ ammonia angle of aperture animal animalcules antheridia apparatus blue body boiling brass calculi Canada balsam carbonate cells cement chemical chloride cilia color compound condenser consists containing crystalline crystals cystine deposit diameter diatoms Dict dissolved drop evaporated examination eye-glass fluid focus glass slide globules grains hair heat hydrochloric acid inch infusoria insects insoluble instrument iodine lens lenses liquid magnifying power margin means membrane micro micro-chemical micrometer microscope microscopist minute mounted mounted dry nitric acid object object-glass observed opaque organic ounces oxalate of lime phosphate piece placed plants plate polarizing potash potassa precipitate present preservative prism quantity rays of light reagents refracted removed render salt soda soluble solution spores stage micrometer structure substance sulphuric acid surface thick thin glass cover tion tissues transparent tube turpentine urate urate of ammonia uric acid urine vegetable vessels
Popular passages
Page 90 - The coal is macerated for about a week in a solution of carbonate of potass ; at the end of that time, it is possible to cut tolerably thin slices with a razor. These slices are then placed in a watch-glass with strong nitric acid, covered, and gently heated ; they soon turn brownish, then yellow, when the process must be arrested by dropping the whole into a saucer of cold water, or else the coal would be dissolved.
Page 55 - The worst of all positions is that in which we look downward vertically. 4. If we stand straight up and look horizontally, parallel markings or lines will be seen most perfectly when their direction is vertical; viz. the direction in which the lubricating fluid descends over the cornea. 5. Every part of the object should be excluded except that which is under immediate observation. 6. The light which illuminates the object, should have a very small diameter. In the daytime it should be a single hole...
Page 10 - They are found not only in the fresh water of ponds, brooks, rivers, and lakes, but even in the salty waters of the great deep, in some strong acids, in terraqueous matter, and in vegetable and animal fluids; indeed, there is no part of the world, either upon its external surface, or internally, but in which these microscopic beings can be found in either a living or fossil state. The mortar of the builder, the chalky cliffs of Albion, extensive tracts of country in various parts of the world, as...
Page 11 - ... it will pay to adulterate. Nay, to such a pitch of refinement has the art of falsification of alimentary substances reached, that the very articles used to adulterate are adulterated ; and while one tradesman is picking the pockets of his customers, a still more cunning rogue is, unknown to himself, deep in his own!
Page 55 - ... 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. This arises from the perfect stability of his 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 downward vertically.
Page 249 - ... 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 61 - ... of the fine motion, and move it briskly backwards and forwards in both directions from the first position. Observe the expansion of the dark outline of the object, both when within and when without the focus. If the greater expansion, or coma, is when the object is without the focus, or farthest from the Objective, the lenses must be placed farther asunder, or towards the mark
Page 235 - ... ends gently fused in the flame of a spirit-lamp. One end is then coated outside with sealing-wax and spirit, or some other coloured liquid, so that the same end may always be used for the same purpose. They are of use for removing objects from water or other liquids in which they may be contained. Suppose, for instance, it is required to examine some deposit lying at the bottom of a liquid, or an object suspended, the fore-finger of the hand in which the tube is held is placed upon the upper...
Page 254 - The tenuity of the vessels of the mollusca often renders it impossible to tie the pipe in the usual manner. The capillaries are, however, usually very large, so that the injection runs very readily. In different parts of the bodies of these animals are numerous lacunae or spaces, which communicate directly with the vessels.
Page 57 - ... rays of the flame, white light. The combination which I find to answer best is the following : — One piece of dark blue glass, free from any tint of red, one of a very pale blue with a slight shade of green, and two of thick white plate glass, all cemented together with Canada balsam.