Popular Science Monthly/Volume 52/November 1897/Minor Paragraphs

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MINOR PARAGRAPHS.

The excitement over the discoveries of gold in the Klondike has caused attention to be directed again to the search for the precious metal. Long neglected deposits are re-examined, the gravels of farms are inspected, and bits of sparkling yellow dirt are collected, to have it determined whether there may not be real gold in them. The officers of the mint in Philadelphia are kept busy testing the specimens sent to them. Hardly a day passes, we are told, that the assayers are not called upon for this purpose, and samples of supposed gold and silver quartz and of sand come into the mint by mail and by express. These specimens include every variety of shining rock and dust—pyrites, mica, talc, common sand, and rock sprinkled with crystals; and along with them often come letters which suggest how bitter will be the disappointment of the senders when they learn that the precious stuff from which they anticipate so much is only "fool's gold." They might learn the real nature of their treasure nearer home, but no jeweler's or metal worker's reply will do for them. Nothing but what they consider the highest expert authority will satisfy them.

The investigations by Prof. Wesley Mills of the psychic development of the rabbit and the cavy or guinea-pig are interpreted by him as illustrating sharp contrasts at birth and for some time after in animals that in mature life have much physically and psychically in common. The cavy soon after birth is able to care for itself and can maintain an independent existence. The rabbit at birth is blind, deaf, incapable of any considerable locomotive power, and is, generally speaking, in a perfectly helpless condition; but it attains comparative maturity in a month. So simple is the psychic life of both animals that there is little to note in them by way of advance after they are a few weeks old. After the first month of existence comparison with the dog, cat, and allied creatures ceases to be suggestive. The rodents are quite left behind. They seem capable of little education from man or Nature.

In describing, in the American Association, the Features of Recent Geology around Detroit, Prof. Frank B. Taylor ascribed the extreme flatness of the country mainly to the fact that it was for a long time the bottom of a lake. As the ice sheet retreated northward in the Detroit Valley and northeastward on Lake Erie, it blocked the escape of the water, and a great lake was formed in front of the ice, covering all the Detroit region and all the lowlands around the western end of Lake Erie. A terminal moraine crosses the Detroit River in the vicinity of Detroit and Trenton, but it was laid down in deep water and is not a prominent feature. For a considerable time the water of this glacial lake was nearly two hundred feet deep over the present site of Detroit. The lake covered all the area of Lake Erie and the low border lands, part of the west end of Lake Ontario, and the southern half of Lake Huron. Its outlet was westward from Saginaw Bay across Michigan through the valley of the Grand River to Lake Chicago (filling the southern part of Lake Michigan), and thence by the Chicago outlet to the Mississippi River. The subsequent history of the lake, as disclosed by the geology, is sketched in the paper.

In a paper read to the American Association upon the scale insects which secrete wax, Dr. L. O. Howard showed that although industries of considerable importance have been derived from the secretions of such insects in Oriental regions, nothing of the kind has so far been done in America. Yet several species exist in the Southwestern States which might possibly be of commercial value. Thus a bark louse is found upon three species of oak in southern California, in practically unlimited supply. A partial chemical investigation has shown that while a very excellent wax may be dissolved by means of chloroform from the insect mass, an insoluble residue remains which has a general resemblance in physical properties to India rubber.

Of the difficulties attending the use of expert testimony in court, Chairman Galbraith, of the Section of Chemistry in the American Association, said that "we are now possessed of so very little of that which may one day be known, that no true scientist hesitates to plead legitimate ignorance, but what really troubles us upon cross-examination is that the court does not speak our language, a language often difficult of direct translation; and the fact that it is but rarely schooled in the principles of our science, and, in consequence, frequently insists upon categorical answers to the most impossible kind of questions." When the expert's testimony has been muddled in this way in the cross examination, the confusion can not be remedied on the redirect examination, because of the lack of familiarity of the friendly attorney with the subject. This leaves the witness in the position of seemingly disagreeing with his own testimony. As a remedy for this the author favored an appeal to the court, urging that the oath requires the whole truth and not a misleading portion of it. In order to secure clearness the expert should avoid technicalities as much as possible.