The microtomist's vade-mecum : a handbook of the methods of microscopic anatomy / by Arthur Bolles Lee.

  • Lee, Arthur Bolles, 1849-1927.
Date:
1885
Catalogue details

Licence: Public Domain Mark

Credit: The microtomist's vade-mecum : a handbook of the methods of microscopic anatomy / by Arthur Bolles Lee. 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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    fibre in all of its physiological states may be obtained and preserved as records of moments whose duration is measured by fractions of a second. Tlie processes tliafc have been imagined for the preparation and permanent preservation of protozoa form another case in j)oint. By simply fixing the animals on the slide by means of picric acid or osmium they may be stained, cleared, and mounted either in an aqueous medium, or in balsam, as successfnlly as the tougher tissues of higher organisms. To attempt to mount them in any medium without first sub- jecting them to that preliminary hardening brought about by the use of filing agents would be hopeless. Lastly, I may give an example of the usefulness of fixation in cases in which it is desired to prepare contractile organisms in their natui'al extended state. Suppose you wish to mount a hydra with the tentacles extended, it is obvious that the animal must be killed with the utmost rapidity or the tentacles wiU be with- drawn before death, and you will have no means of getting them extended afterwards. If the animal be placed in a cell with a few drops of water, and if as soon as the tentacles are fully extended you add one drop of 2 per cent, solution of osmic acid the hydra will be killed with such lightning speed that not a tentacle will be retracted (Ranvier). In blood we have an example of a tissue of which it is simply impossible to obtain permanent preparations well preserved without previous fixing. But if blood be treated, as a first step in the process of preparation, with picric acid or corrosive sublimate, it may be stained and mounted in some preservative medium with such success as to be avail- able for the most minute study. And the same is true in general of other tissues. Fresh tissue-elements or portions of tissue cannot be kept as preparations without undergoing modifications, such that after a few days their whole character is changed. Certain liquids have for a long time been recom- mended as having the property of preserving indefinitely