Practical pathology : a manual for students and practitioners / by G. Sims Woodhead.
- Woodhead, G. Sims (German Sims), Sir, 1855-1921.
- Date:
- 1892
Licence: Public Domain Mark
Credit: Practical pathology : a manual for students and practitioners / by G. Sims Woodhead. Source: Wellcome Collection.
79/704 page 55
![moderately fresh, and often even where slight putrefactive changes have commenced, it is an exceedingly good plan to stop the putrefaction and to fix the elements of the tissue as far as possible by the use of bichloride of mercury before hardening them in spirit. Dissolve 7*5 grammes of bichloride of mercury in 100 parts of normal saline solution (7 per cent, common salt in water). In this, place portions of tissue about the size of a small bean, and allow them to remain for from 6 to 24 hours, then wash thoroughly in w^ater, after which place them in a 30 per cent, solution of spirit to which a few drops of tincture of iodine have been added, the iodine serving to combine with and precipitate all the mercury that is left in the tissues, re-dissolve in weak iodide of potassium solution and wash thoroughly; then place the pieces in 50, 75, and 90 per cent, spirit and absolute alcohol, each for 24 hours, after which the specimens may be embedded and cut. Chrojiiic add, alone or in the form of some salt, is very frequently used as a hardening reagent. Of the combinations into which it enters— 59. Miiller's fluid is the most useful, especially in the preparation of delicate tissues, in which it fixes the protoplasm of the cells rather than hardens them, and thus causes but little shrinking of the tissues, so that for congested organs or mucoid tissues it is invaluable. To prepare it, take of Potassium bichromate, . . . . 2]^, parts. Sodium sulphate, ..... i part. Water, . . . . . .100 parts. Care is to be taken to put in only one volume of tissue to twenty of fluid, as with all other methods. Change the fluid at the end of the first, third, and seventh days, and then at the end of each week till the end of the fifth; transfer to water for several hours after the tissue has been in the fluid for six or eight weeks, and then again to dilute methylated spirit; leave in this for from twenty-four to forty- eight hours, and then preserve in strong methylated spirit. The great advantages of Miiller's fluid are, that there is no great danger of over- hardening, and although the process takes a considerable time, the results are almost invariably satisfactory ; that the red blood corpuscles](https://iiif.wellcomecollection.org/image/b20388895_0079.jp2/full/800%2C/0/default.jpg)
