Loading
  • 21 Aug, 2019

  • By, Wikipedia

File:SalvatoreLoBianco.jpg

"Cylindrical glass jars, with glass stoppers ground to fit, are used for exhibition purposes aud for storage. Those with necks are employed for the most part, but those without necks and with a flat top are preferred for elegant installation. Cylindrical jars are the most economical of fluid and are the cheapest to get.For convenience in suspending objects in the liquid, those having a glass hook in the under side of the stopper should be obtained Since glass jars are expensive, earthenware jars and basins are used for many laboratory manipulations. The small, globular vessels which have the bottom formed by a glass stopper, concave within, are recommended for small spherical animals. Kound- bottomed glass tubes are very useful, but care must be exercised to see that the walls are not too thin. The edge of the orifice should be smoothed in the Buusen flame. When the tubes are more than 30 mm. (1.2 inches) in diameter, the lip should be flared out so that a piece of bladder can be readily tied over the opening.

Corks should be selected from the best stock, should be as compact as possible, and should be without cracks or other defects. In form they should be cylindrical, so as to make a good joint with the sides of the tube. The ends must be flat, with clean cut edges, so that no fragments can get into the alcohol. With large tubes it is desirable to put a plug of cotton inside the tube next to the cork, since the alcohol extracts the tannic acid from the cork and is stained brown thereby.

To preserve small, delicate animals, such as eggs and larvie, it is well to place the small tube containing the objects in alcohol, closed with a cotton plug, inside a larger vessel, which is likewise filled with alcohol. This p,rraugement prevents danger from evaporation and minimizes the liability to breakage. One must see, however, that the cotton contains no acids and does not stain the alcohol. Absorbent cotton is the most suitable, of course, but the best quality of ordinary cotton will answer every purpose.

For large, flat objects, such as Asterids, Pleuronectids, and the like, rectangular jars with flat sides are recommended. These jars are made to be closed with a plate of glass, cemented on. Gutta-percha cement is generally used. Such receptacles have the great advantage that they do not distort the view of the object within them. For delicate forms, which are long and stiff, like Funiculina glass tubing of proper size, cut off at the right length, is used, one end being closed in the Bunsen flame and the other with a cork.

For preliminary manipulations much use is made of glass crystallizing dishes with flat bases and perpendiular sides, in which many specimens can be placed in little liquid without touching or interfering with one another. They are especially advantageous for keeping animals alive in sea water, letting them remain at rest until thoroughly distended; for killing by different methods, either slowly or quickly, and for hardening objects in different solutions until they are transferred to permanent receptacles. These crystallizing dishes have ground edges so that they may be tightly covered with disks of glass, when desirable. For hardening worms and other elongated animals use may be made of long rectangular vessels covered with a sheet of glass, or of the zinc trays to be described later.

It is also necessary to have a number of ordinary beakers (or battery jars) of diiferent sizes, which serve for the preserving of animals alive, tubes for the reception of small animals, pipettes for the extraction of minute forms from jars of water, glass rods, reagent bottles, graduated cylinders, etc.

For preserving animals, especially fish, of a size too great for such glass receptacles as have been mentioned, a rectangular case or box of zinc with a shallow trough around the margin is very useful. The cover, likewise of zinc, has its edge made to fit into the trough. To prevent evaporation the trough may be filled with water and a layer of oil. The cover has an opening in the middle to permit the escape of the air which is compressed under it by closing the box. This opening is provided with a cork. It must be acknowledged that these boxes have the disadvantage that, after a time, the zinc becomes corroded, probably by some acid formed in the alcohol through the action of dead animal matter. It is a good plan to protect the metal box by an exterior wooden case. In place of the rectangular vessels of glass for hardening animals of elongated form, the station uses some made of zinc with a layer of waxin the bottom. The wax bottom is for the purpose of holding the wooden pins used in straightening out worms while they are hardening. Pins of orange or other hard wood are preferable to those of metal, because the fixing fluids attack metals. A convenient size for such a tray is 60 by 6 by 6 cm. with about 1 cm. of wax in the bottom.

For the transfer of objects from one receptacle to another spatulas are largely used. These are made preferably of horn, because that material is not attacked by the reagents in use. They range in size from 6 mm. (one-fourth inch) to 10 cm. (4 inches) in width, and are of a convenient length, say 17.5 to 20 cm. (7 or 8 inches).

A pair of soft iron forceps 30 cm. (12 inches) long is very convenient for taking objects out of deep receptacles. Iron is both cheaper and just as good as brass for that purpose. Small forceps, wire cutters, syringes, and so on are used at times.

The apparatus for narcotizing certain Actinians is constructed as follows: The nose of a pair of bellows is provided with a metallic bowl which fits over the metal bowl of a tobacco pipe. The latter is provided with a peg which fits into a slot in the bowl on the bellows and fastens the two together. The tube of the tobacco pipe is continued with a piece of flexible rubber tubing which terminates in a U-shaped piece of glass tubing, the distal end of which has been drawn out to a point. With this apparatus one can easily force smoke into a receptacle
Date before 1910
date QS:P,+1910-00-00T00:00:00Z/7,P1326,+1910-00-00T00:00:00Z/9
Source http://researcharchive.calacademy.org/research/scipubs/pdfs/v55/v_55_suppII/proccas_v55_n06_suppII.pdf Author Unknown authorUnknown author

Licensing

Public domain
Public domain
This media file is in the public domain in the United States. This applies to U.S. works where the copyright has expired, often because its first publication occurred prior to January 1, 1929, and if not then due to lack of notice or renewal. See this page for further explanation.

United States
United States
This image might not be in the public domain outside of the United States; this especially applies in the countries and areas that do not apply the rule of the shorter term for US works, such as Canada, Mainland China (not Hong Kong or Macao), Germany, Mexico, and Switzerland. The creator and year of publication are essential information and must be provided. See Wikipedia:Public domain and Wikipedia:Copyrights for more details.

Captions

Add a one-line explanation of what this file represents

Items portrayed in this file

depicts

18 May 2012

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeThumbnailDimensionsUserComment
current19:09, 18 May 2012Thumbnail for version as of 19:09, 18 May 2012506 × 386 (79 KB)Notafly

The following page uses this file:

Global file usage

The following other wikis use this file:

Metadata