lxxx Journal of Proceedings.
occurred to me that the substance which had such great powers as
an antiseptic might be useful for microscopic purposes.
Boro-glyceride is a solid composed of boracic acid and glycerine,—not
merely mixed but chemically united,—a compound of which the elements
of water in the glycerine are displaced by boracic acid.* Boro-glyceride
exists in two forms, the glacial and hydrated. The glacial form
appears to be the best preservative. It is, in appearance, very much
like ice, very brittle and very deliquescent. The hydrated form is a
pasty white mass soluble in warm and cold water. At present the
only form of boro-glyceride sold is the hydrated, and this is used
dissolved in water as a food preservative and as an antiseptic
dressing for wounds.
The solution of boro-glyceride has no poisonous or unwholesome
properties, is perfectly colourless and odourless, and does not stain
the skin or fabrics.
Knowing well that no amount of reasoning will discover the result
of any chemical process, I set to work to experiment and put up at
first two objects to test crucially the substance as a preservative for
objects for the microscope. The medium used was a saturated solution
of glacial boro-glyceride in distilled water. The objects put up were :—
(1) Transverse section of a stem of garden Nasturtium (Tropaeolum).
(2) Transverse section of ovary of Fuchsia.
These were mounted in zinc cells. The zinc rings were fastened to
the slips with marine glue, and the thin glass covers cemented on with
gold size.
These were then put up for twelve months to test the keeping
qualities. During that time no oozing took place, and the slides have
not been touched in any way. They have been shown to various friends,
and last of all I determined to submit them to our President, Professor
Boulger. It is entirely owing to his suggestion that I have ventured to
trouble the Club with so small a matter, I regret that my leisure is so
little that I have been unable to pursue the experiments further, but I
hope to be able to do so during the coining summer. I shall be
extremely gratified if others will try, and record results, for the substance
seems to promise to be very useful in preserving delicate tissues in a
fresh and unchanged state.
Mr. W. Cole made some observations on the precautions necessary in
using these dense media (glycerine, metallic solutions, &c.) in the
preservation of delicate animal and vegetable organisms. The specimens
should first be placed in a very weak solution of the preservative, and
then removed gradually to stronger and stronger solutions until the
delicate cell walls and cell contents had become sufficiently permeated
therewith to withstand the destructive exosmotic action of the saturated
solutions. By attending to these rules, he had found no difficulty in
using the densest media in the examination of the most fragile
embryonic insect structures, &c.
The Secretary read the following note from Mr. Worthington Smith,
accompanied by the drawings referred to:—
"It is doubtful whether I shall be able to get down to the meeting
to-morrow, so I send these sketches for exhibition. They give four
* It is doubtful whether " boro-glyceride " is a definite chemical compound.—Ed.