Scientific American Supplement, No. 717, September 28, 1889 eBook

This eBook from the Gutenberg Project consists of approximately 147 pages of information about Scientific American Supplement, No. 717, September 28, 1889.

Scientific American Supplement, No. 717, September 28, 1889 eBook

This eBook from the Gutenberg Project consists of approximately 147 pages of information about Scientific American Supplement, No. 717, September 28, 1889.
of cold to the surface of the body, and in this case the thermotaxic centers in the brain most probably play some part.—­Dr. Herter gave an account of experiments made by Dr. Popoff on the artificial digestion of various and variously cooked meats.  Lean beef and the flesh of eels and flounders were digested in artificial gastric juice; the amount of raw flesh thus peptonized was in all cases greater than that of cooked meat similarly treated.  The flesh was shredded and heated by steam to 100 deg.  C. The result was the same for beef as for fish.  When compared with each other, beef was, on the whole, the most digestible, but the amount of fish flesh which was peptonized was sufficiently great to do away with the evil repute which fish still has in Germany as a proteid food.  Smoked meat differed in no essential extent from raw meat as regards its digestibility.

* * * * *

PRESERVATION OF SPIDERS FOR THE CABINET.

For several years past, I have devoted a portion of my leisure time to the arrangement of the collection of Arachnidae of the Natural History Museum of the University of Gand.  This collection, which is partially a result of my own captures, is quite a large one, for a university museum, since it comprises more than six hundred European and foreign specimens.  Each group of individuals of the small forms and each individual of the large forms is contained in a bottle of alcohol closed with a ground glass stopper, and, whenever possible, the specimens have been spread out and fixed upon strips of glass.

The loss of alcohol through evaporation is almost entirely prevented by paraffining the stoppers and tying a piece of bladder over them.

Properly labeled, the series has a very satisfactory aspect, and is easily consulted for study.  The reader, however, will readily understand how much time and patience such work requires, and can easily imagine how great an amount of space the collection occupies, it being at least twenty times greater than that that would be taken up by a collection of an equal number of insects mounted in the ordinary way on pins and kept in boxes.

These inconveniences led me to endeavor to find out whether there was not some way of preserving spiders, properly so called, in a dry state, and without distortion or notable modification of their colors.

Experience long ago taught me that pure and simple desiccation, after a more or less prolonged immersion in alcohol, gives passable results only with scorpions, galeodes, phrynes, and mygales, and consequently with arachnides having thick integuments, while it is entirely unsuccessful with most of the spiders.  The abdomen of these shrivels, the characteristic colors disappear in great part, and the animals become unrecognizable.

Something else was therefore necessary, and I thought of carbolated glycerine.  My process, which I have tried only upon the common species of the country—­Tegenaria domestica, Epeira cucurbitina, Zilla inclinata, etc., having furnished me with preparations that were generally satisfactory.  I think I shall be doing collectors a service by publishing it in the Naturaliste.

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Scientific American Supplement, No. 717, September 28, 1889 from Project Gutenberg. Public domain.