B, I give a specimen of this tissue stained by osmic acid; in Fig.
In its structure there is not the slightest sign of anything of the nature of a heart; it is a solid mass of closely compacted cells, and the cells are all very full of fat, staining intensely black with osmic acid.
These specimens are very instructive, especially those stained by osmic acid, which preserves the natural thickness of this space better than other staining methods.
So named in allusion to the strong chlorinelike odor of osmic tetroxide.
To determine the presence of organisms in a sample of water the best method known at present is to kill and coagulate them by means of osmic acid or chloride of platinum, and allow them to subside.
The embryo was hardened in a mixture of osmicand chromic acids.
Transverse section through the ovary of an embryo rabbit of twenty-two days, hardened in osmic acid.
The commissures stain very deeply with the mixture of osmic and chromic acid, and form one of the most conspicuous features in successful longitudinal sections of embryos so hardened.
Osmic acid specimen illustrating the same points as the previous section.
Transverse section through the ovary of an embryo rabbit of eighteen days, hardened in osmic acid.
The figures which are tinted represent sections of embryos hardened in osmic acid; those without colour sections of embryos hardened in chromic acid.
Its oxidizing power is so great, as to transform not only the formic acid into the carbonic, and alcohol into vinegar, but even someosmic acid, from the metallic osmium.
Defn: Denoting those compounds of osmium in which the element has a valence relatively lower than in the osmic compounds; as, osmious chloride.
Osmium tetroxide (OsO{4}) is a very volatile liquid and is used under the name of osmic acid as a stain for sections in microscopy.
Possibly some of the beautiful preparations in the Fisheries Exhibition of 1883 were prepared in this manner, and such objects as the sea-anemones, with tentacles expanded as in life, may have been instantaneously killed by osmic acid.
For delicate researches, especially in the ciliated infusoria, it is better than osmic acid, without its great cost, and is everywhere easily obtained.
Ignited in the open air, it is oxidized to volatile osmic acid, which is possessed of a pungent smell, and affects the eyes.
The metal osmium, if exposed to the flame of oxidation, fuses and is finally dissipated as osmic acid.
With osmic fixation safranin gave better results in some cases, because of the abundance of spindle fibers and sphere substance which were stained by haematoxylin.
The mercuro-nitric solution and Lenhossek's fluid gave excellent fixation and were preferable to the osmic mixtures when it was desirable to stain the same material with iron-haematoxylin, and also with various anilin stains.
The spindle in both divisions is peculiar in having outside of the spindle proper a dense mass of fibers which, in osmic material, stain deeply with iron haematoxylin.
Osmic acid* is invaluable for staining fatty particles in the cells.
The tissue must be very thoroughly washed in running water to remove all traces of osmic acid, and then stained for a couple of days in borax carmine to demonstrate the nuclei and axis cylinders.
Osmic acid is also a most valuable staining reagent (see p.
Harden in osmic acid, or Müller’s fluid and spirit.
The leg of an insect such as a cockroach may be hardened in osmic acid.
One specimen should be stained with osmic acid and picrocarmine and mounted in Farrant’s medium, and another in eosine and hæmatoxyline and mounted in Canada balsam.
The section is again floated off into the bowl of water and thoroughly washed to free it from the osmic acid.
For rapidity of action, and for rapid fixing of all the tissue elements in their natural position osmic acid is one of the best hardening reagents we possess.
As soon as a good section is obtained the razor should be plunged into a large bowl of cold water to detach the section, which is at once floated on a glass slide, and osmic acid solution, 1/4 per cent.
Specimens should be hardened in osmic acid or in Müller’s fluid, and cut in celloidin, or paraffin.
Another section should be stained in osmic acid, followed by methyl violet, as waxy and fatty degeneration frequently co-exist.
It is then left exposed to the air to get rid of all traces of osmic acid, and may afterwards be stained as described below.
Harden the trachea of a recently killed cat in osmic acid or Müller’s fluid.
It consists in fixing the dry preparation for 20 minutes in osmicacid vapour, and staining in a concentrated watery solution of methylene blue.
According to Müller these bodies are not blackened by osmic acid, and probably contain no fat; they seem to have no connection with fibrin formation, as they always lie outside the fibrin network.
Observations on the yolk spherules may be made either in living ova, in ova hardened in osmic acid, or in ova hardened in picric or chromic acids.
This stage I have not met with, nor can I see any grounds for connecting these bodies with the formation of the yolk, and the fact of their not staining with osmic acid is strongly opposed to this view of their function.
That no yolk spherules are present in the cells of the follicular epithelium, in which they could not fail to be detected, owing to the deep colour they assume on being treated with osmic acid.
In an ovary about this stage, hardened in osmic acid, the epithelium stains very differently from the subjacent stroma, and the line of separation between the two is quite sharp.
It is very difficult in the osmic specimens to make out clearly the exact outlines of the various structures, the nuclei in many instances being hardly more deeply stained than in the protoplasm around them.
On the whole I have found osmic acid the most suitable reagent for the study of the yolk, since without breaking up the developing spherules, it stains them of a deep black colour.
The younger of these ovaries was from a Scyllium embryo 10 centimetres long, preserved in osmic acid.
The ovary of this age was preserved in osmic acid, which is the most favourable reagent, so far as I have seen, for observing the relation of the stroma and epithelium.
These globules are easily recognized from the fact that they are stained black by osmic acid and red by Sudan III.
Greasy finger-marks may also be acted on chemically, so as to bring out details by the application of osmic acid.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "osmic" in a variety of sentences. We hope that you will now be able to make sentences using this word.
