The Preparation and Mounting of Microscopic Objects |
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acetic acid alcohol Algæ ammonia amongst animal beautiful objects become benzole betwixt boiling bottle bubbles camel-hair pencil Canada balsam carmine cells cement centre Chapter chloroform chromic acid clean colour crystals described Diatomaceæ diatoms diluted dissection dissolved distilled water drachm dried drop easily edge employed examined flat fluid Foraminifera forceps gelatine glass slide glycerine gold-size grains heat hydrochloric acid immersed inch injected injured insects laid larvæ matter mentioned method microscope microscopist minute mixture mode mounted dry mounted in balsam naphtha necessary needle nitric acid object-glass obtained opaque objects ordinary ounce perfectly piece placed plate polariscope polarized light portion potash prepared preservative liquids pressure procured purpose quantity readily recommended removed render ring salt sections shells soaking solution sometimes specimens structure student substance surface syringe thick thin glass cover tion tissues transparent tube turpentine usually varnish vessels warm washed whilst wood
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Page 144 - ... 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. The slices thus treated appear of a darkish amber color, very transparent, and exhibit the structure, when existing, most clearly.
Page 192 - ... dissolved. Then take a Winchester quart-bottle, and mark upon it the line to which 16 ounces of water extend. The coloured solution must then be filtered into the bottle, and pure water must be added until the whole is equal to 16 ounces. Next dissolve 600 grains of potash-alum in about 10 fluid ounces of water, and add to this, under constant boiling, a solution of carbonate of soda, until a slight permanent precipitate is produced. Filter and add water up to 16 fluid ounces. Boil, and add this...
Page 95 - ... out on the opposite side of the cell till it is full of balsam ; then take up the cover and carefully place upon it a small streak of Canada balsam from one end to the other ; this, if laid on the cell with one edge first, and then gradually lowered till it lies flat, will drive all the air before it, and prevent any bubbles from being included in the cell. It can be easily put on so neatly as to require no cleaning when dry. If the cover is pressed down too rapidly the balsam will flow over...
Page 143 - The coal is macerated for about a week in a solution of carbonate of potash; 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. The slices thus...
Page 192 - ... renewed, and the bottle filled up with cold water. After allowing the precipitate to settle for a day, draw off the clear supernatant fluid with a syphon. Repeat the washing until the clear fluid gives no precipitate with chloride of barium.
Page 125 - My formula is as follows : Take any quantity of Nelson's gelatine, and let it soak for two or three hours in cold water — pour off the superfluous water, and heat the soaked gelatine until melted. To each fluid ounce of the gelatine add one drachm of alcohol, and mix well ; then add a fluid drachm of the white of an egg. Mix well (whilst the gelatine is fluid, but cool) . Now boil, until the albumen coagulates, and the gelatine is quite clear.
Page 156 - A portion of shaved scalp being placed between the two thin slips of deal, a piece of string is tied round them so as to exercise a slight degree of compression ; the preparation is now laid aside for about twenty-four hours, when it is found to have dried to an almost horny condition. It then adheres firmly by its lower surface to one of the slips, and thus it can be held securely, while extremely thin and equable sections are cut with great facility in any plane that may be desired. These sections,...
Page 125 - He takes a quantity of Nelson's gelatin, soaks it for two or three hours in cold water, pours off the superfluous water, and heats the soaked gelatin until melted. To each fluid ounce of the gelatin, whilst it is fluid but cool, he adds a fluid drachm. of the white of an egg. He then boils this until the albumin coagulates and the gelatin is quite clear, when it is to be filtered through fine flannel, and to each ounce of the clarified solution add 6 drachms of a mixture composed of 1 part glycerin...
Page 144 - The slices thus treated appear of a darkish amber-colour, very transparent, and exhibit the structure, when existing, most clearly. We have obtained longitudinal and transverse sections of coniferous wood from various coals in this way. The specimens are best preserved in glycerine, in cells; we find that spirit renders them opaque, and even Canada balsam has the same defect...