The herald. [microfilm reel] (Los Angeles [Calif.]) 1893-1900, 1895-11-28

Formalin is a preservative that has
been favorably known for about ten
years, and IS used in all important bio
logical laboratories in the country.
1t has not been used enough in Caliior-
MIA to get fully in the market but in the
east it is common, cheap and popular.
1t is derivative from wood Split
(mettylslcohoD and was discovered in
1868 by A. W. Hoffman. 1t is sometimes
called formol. 1t is a clear liquid with a
pleasant odor, and has the quality of dis.
injecting, hardening and preserving
vegetable and animal tissue.
About 1898 DR.. +. Blum discovered that
formalin, besides its antiseptic proper
ties, possessed the noteworthy property of
hardening animal tissues without their
shrinking and without altering their
microscopic structure or staining prop.
critics."
This is an i'm portant discovery, for al.
cohul, the mmonest preservative. be-
sides shrinking the tissues will, after
to render them useless for microscopIcal
study.
Other agents are either open to the
same charge or are much more expens-
i've than formalin.
FOrmaiin comes nearer q universal and
perfect preservative than anything yet
discovered. 1t is used in various proper
tons, according to the tissue to be pre-
served. and tho strength varies from one
part formalin to eight parts water, to
one formalin to one hundred OF water.
Delicate and small specimens, like hydri-
oids and bugulae need very small
| amount of formalin. Good results are
| obtained by using alcohol and formalin,
| Cor alternating the two), for animal It's
| sues; and chrome alum with few drops
OF formain for vegetable tissues.
| In 1894. while at Woods Holl biologi-
| cal laboratory, l became interested in
this preservative, and for more than a
| year | nave been experimenting with il
| in the normal school biological labora-
| | have ever used.
One test of it was interesting. At
| WOODS Holl l bought sponges, hydroids,
marine worms, sea cucumbsrs. bugulae,
! marine and fresh water algae and various
eastsrn fungi, all carefully put up in for
| malin. and they came across the conti-
nent as freight. We did not know how
the new material would stand the shaking
| and the extremes of heat and cold Incl
dent to the 3000-mile journey. 1t was
| enough to test the quality of any preserv-
alive. Foramlin stood it we'll. All the
| SptClUcuS III BOOu WIN th0
| liquid as clear as when it started.
l have used formalin on hepaticae,
| marine and fresh water algae, fungi, fish,
| sponges, corals, sea anemones, worms,
molluscs ami the shape and structure has
remained perfect, but the color has faded
| from nearly all the specimens, both OF
animal and vegetable.
| 1t may be OF interest to some fellow
| teacher to know moro fully how the spec
| linens were affected.
| In the solution of one part formalln
| to eight parts water nGstOe, after six
months is somewhat faded but most of
the specimens are still decidedly blue
green, though some are faded to a dirty
white, but the. shapes Of the masses are
preserved and the filaments are un-
| shrunken and unchanged.
Spirogyra conjugating has the chloro-
! phyll less green, more inclined to brown
| ish, as the older tilaments become even
| in the ponds, but the chlor ophyIl bands,
resting spores and cell contents are per-
| feet.
Zygnema 10 the most exasperating OF all