MICROSCOPY. : 781 
OUNTING Tissues IN BAtsam. — Portions of thin membranes, 
f other tissues, especially when stained with carmine, silver 
gold, may be transferred through alcohol to balsam by the 
following method described by Dr. J. J. Woodward. The prepa- 
tations are examined in glycerine on a glass slide and under a 
thin glass cover, and they may be kept in this condition, without 
further preparation, for several weeks. When one is to be perma- 
nently preserved the cover is to be fastened down by a spring clip, 
d the whole arrangement immersed in seventy-five per cent. 
cohol for a few days; after which it is transferred, for the same 
length of time, to absolute alcohol. The object may then be 
_ removed from its position under the cover, and it will be found 
_-Sufliciently dehydrated to be mounted in balsam in the ordinary 
4 Way. By this transfer to balsam, permanency is gained and cor- 
- Tugation and distortion are reduced to a minimum. 
Mounting Tissues 1x Dammar Varnisu. — Dr. J. W. S. Arnold 
_ transfers sections of stained tissues from water to seventy-five per 
Gent. alcohol. After soaking ten or fifteen minutes, the specimen 
is clarified by oil of cloves and immediately mounted in dammar 
_ Varnish or balsam dissolved in chloroform. The distortion caused 
= by absolute alcohol is avoided, and the objects are rendered 
:  Sufficiently transparent. 
: — Loewoon Staining Fivur.— Hematoxylin is preferred to car- 
_ mine as a means of staining tissues, by some microscopists. Dr. 
J. W. S. Arnold prepares the solution by rubbing together in a 
= Mortar one part of common logwood extract and three parts (by 
Measure) of pulverized alum, and afterwards gradually adding 
enough water to dissolve only a part of the powder. The satu- 
Tated solution thus formed should be of a dark violet color. If 
too red, more alum must be added. After standing several days 
Ìt is to be filtered and diluted by one-fourth its bulk of seventy- 
ve per cent. alcohol. 
Foner In Drinking Warer. — Prof. James Law found fungi in - 
te blood and in the milk of cows who drank water abounding in 
latoms and spores. The health of the cattle was manifestly im- 
Only a part of the cows drinking the water were suscep- 
ble to its effect, and they recovered after a change of water and 
the use of bisulphate of soda. The organisms observed are figured — 
“The Lens.” a 
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