Text-book of histology : including the microscopic technic / by Philipp Stöhr.

  • Philipp Stöhr
Date:
1898
Catalogue details

Licence: Public Domain Mark

Credit: Text-book of histology : including the microscopic technic / by Philipp Stöhr. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    from three to ten hours the 70 per cent, should be replaced by 90 per cent alcohol. The immersion in the silver solution should be done under exclusion of sunlight; the reduction, on the other hand, should be undertaken only with sunlight.* If the sun does not shine, the object, after treatment with the silver solution and washing in distilled water, is to be preserved in the dark in 30 cc. of 70 per cent, (later 90 per cent.) alcohol, and in this exposed to sunlight at the earliest opportunity. 13. Go/gi's black'' reaction for demonstration of the elements of the nervous system.f This method unites fixing and staining. The objects must be as fresh as possible, and in general their diameter should not exceed 4 mm. It is not easy to cut fresh brain into pieces of this size with- out bruising the delicate tissue; therefore place larger pieces (up to 3 cm. cubes) in a small glass jar containing freshly prepared Golgi's mixture (p. 21), which is to be covered and stood in the dark (in winter it must be put in an oven having a temperature of about 25° C). In from one to two hours the pieces can easily be cut into slices about 4 mm. in diameter. The quantity of Golgi's fluid to be used is regulated by the number of the slices, each shce requiring about 10 cc. of the mixture. In from two to six days, less often fifteen days,t the slices are taken out, quickly washed for a couple of seconds in distilled water, gently dried with filter-paper, and placed in 0.75 per cent, silver solution (30 cc. of the I per cent, solution [p. 22] plus 10 cc of distilled *The reduction takes place in ordinary daylight, but slowly, and yields less satisfactory results. , i» \ Editor's remark: In American laboratories a modification of Golgi's method by Cox is often used with excellent results. This modification is particularly recommended to beginners, because it is very simple and nearly always successful. In its application the following direc- tions should be observed : Put small cubes, 2 cm. or less, of the organs of the central nervous system of adult or newborn animals for from six to ten weeks into the Cox-Golgi mixture, the formula of which is given on p. 21 (No. 15), using 10 to 20 times the volume of the object treated. Change the fluid at the following intervals : after twenty-four hours ; three days; eight days; fifteen days ; twenty-one days; thirty days. The objects should remain in the mixture until they are to be sectioned, and will keep in good condition for about ten months. '1 hen transfer them directly into 95 per cent, alcohol for one hour ; into alcohol-ether (equal parts) for a half hour ; into thin celloidin solution (in alcohol-ether) for one hour. Mount on a block with thick celloidin solution (see Microtome Technic) and harden in 80 per cent, alcohol for from one to two hours. Cut at once sections from 50 to loo // thick ; clear them in a mixture of xylol, three parts, and carbolic acid, one part, in which they may remain for weeks without injury. Mount in balsam and cover the sections with a cover-glass. In time the specimens thus preserved are not infrequently marred by the appearance of corrosive crystals, but the impreg- nation of the elements of the nervous tissue remains intact. J See Special Technic.
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