Another method is to stain first with logwood and then with a one per cent. solution of safranine in water. Safranine with indigo-carminė also gives very good results.

Stain the sections first with a one per cent. aqueous solution of safranine.

Wash this out slightly and then stain with a five per cent. solution of indigo-carmine in water.

Wash out in water and then in spirit, and care must be exercised that the sections are not washed too much in the spirit as the whole of the safranine may be removed.

If this process is carefully done it gives a very good result, as all the amyloid material is stained a deep blue, while the nuclei of the cells are red and the surrounding tissues a light blue. It requires some practice to hit the right amount of washing.

HYDATIDS.

To make a preparation of hydatid cysts, take a portion of the wall of a large cyst and scrape off some of the gelatinous matter adhering to it. Place a little of this on a slide and tease it gently in a drop of glycerine, cover and examine. If there are any small cysts showing hooklets, &c., well, seal it up with Hollis's glue.

The cysts may be first stained with one of the aniline dyes, and mounted in glycerine after all superfluous colour has been removed.

SHORT HISTORY OF THE MANNER IN WHICH A PORTION OF MORBID GROWTH IS PRepared by thE CHROMIC ACID METHOD.

Ist day. Small pieces placed in chromic acid mixture (page 16).

16th day. Section cut, stained, and mounted.

OF SEALING UP PREPARATION JARS FOR THE MUSEUM.

Of all the various methods that have been tried to prevent the evaporation of spirit from the specimen jars, the following seems to be the best.

A glass cover must be cut to fit the jar, this can be done very quickly with a machine made by Sharratt & Newth, the top of the jar is then ground until it is perfectly even. This is very easily done on a flat stone, such as those used in paving the streets. Some water is placed on the stone, and the mouth of the jar is rubbed steadily on the stone until all uneven surfaces are ground off, a few minutes will do this. Fine

emery powder will assist the process, but is not necessary, and coarse emery must not be used as it will chip off the edges of the jar. Care is requisite in grinding down a large jar, as if it is allowed to jump it will soon crack.

To make the cement, a quantity of sheet gelatine is cut into small pieces, and covered with warm water in a porcelain dish on a water bath, it is stirred with a glass rod until dissolved, and then a small quantity of glacial acetic acid added until it becomes distinctly sour to the taste.

It is then poured into a wide-mouthed bottle, and is ready for use.

TO SEAL UP A PREPARATION JAR.

Place the cover on an iron plate, over a gas burner and warm it.

Cut with a file small notches in the top of the jar for the strings which hold up the preparation to lie in; thoroughly dry the top; for this purpose a piece of heated iron is drawn over it two or three times.

The cement having been made fluid in a water bath is applied to the top with a small brush, the cover is then placed in position and gently pressed down. A small weight in some cases may be placed on it. The jar is then put on one side for twenty-four hours. The space between the edges of the cover and jar is then filled in with warm gelatine solution, and when this is quite hard a ring of Brunswick.

black or Asphalt varnish is painted on it. In sudden changes of temperature from warm to very cold it is advisable not to mount specimens, as the application of heat will crack a large number of the jars. Should the spirit after a length of time become low, it may be renewed without removing the cover. Two small holes should be drilled in the cover with an American drill moistened with turpentine, a small funnel is then drawn out very fine in the gas blow pipe, and inserted in one of the holes and the jar filled up. The holes are sealed with the gelatine.

MODE OF PRESERVING OPHTHALMIC SPECIMENS.❤

Mode of Preparing and Mounting.-The following are the stages of the process:

1. The eye is placed immediately after excision, unopened, in Muller's fluid for about three weeks, light being carefully excluded. It is well to change the fluid every two or three days, otherwise the specimen may be permanently stained; this happens. all the more readily if light be not excluded. The fluid consists of

2. It is than wrapped in a piece of gutta-percha membrane, the surface of which has been greased to

By Priestley Smith, Ophthalmic Review, March, 1883.

prevent adhesion, and frozen solid by immersion in a vessel containing a mixture of ice and salt. The vessel should have a hole at the bottom, so that water may drain away; a flower-pot answers well. To freeze the eyeball solid, takes not less than half an hour; a valuable specimen may be spoiled by disturbance of the internal parts if cut open before it is solid throughout.

3. When frozen it is divided in the required direction by means of a sharp table knife. A thicker blade such as a razor, goes through the frozen globe with difficulty. If the exact position of the section is of consequence, the points through which it should pass should be marked with a spot of ink before freezing.

4. The bisected specimen is placed in a 5 per cent. solution of chloral-hydrate in order to remove the colour of the Muller's fluid, the solution being changed every two or three days until it is no longer discoloured.

5. It is then placed successively in glycerine solutions, 10 per cent., 25 per cent., and 50 per cent., remaining in each for twenty-four hours or more. This process is necessary in order to prevent shrinking of the tissues when the specimen is placed in the jelly.

6. It is then mounted. A specimen-jar being filled with melted jelly, the half-eye is placed in it, the concavity upwards. When every interstice is filled it is turned over, care being taken to avoid the imprisonment of an air-bubble, and held, by means of a needle, in contact with the bottom of the jar. When