Page:Popular Science Monthly Volume 6.djvu/648

630

is Part III. of Mr. Packard's series, "Half-Hours with Insects," which we have already mentioned in the Monthly. The author here considers the relations of insects to man. Of course those insects which live by preying on human kind receive special attention. We do not remember ever before to have heard that the Cimex, or bedbug, is originally a parasite of birds, especially doves and swallows. "The opinion," says Prof. Packard, "that the bedbug originally lived under the feathers of semi-domestic birds is strengthened by the fact that a European species of Cimex lives on the body of the swallow, another on the bat, while a third is found in pigeon-houses." Insects that are of service to man are also considered, and, singularly enough, we find in this category the cockroach, which, instead of being the unmitigated nuisance generally thought, is the mortal foe of the bedbug, and really does good work in ridding our houses of that disgusting pest. The pamphlet is full of useful information, and is well illustrated.

author of this little essay was laughed at by eminent medical authorities in Edinburgh, when, some twenty years ago, he ventured publicly to affirm that certain human diseases may be artificially produced in the lower animals. Things have changed since then, and the identity of various diseases in man and animals is now admitted. Nor is this true of physical diseases only; Dr. Lindsay has found that the lower animals, or at least some of them, not only possess mind resembling that of man, but are subject to the same classes of mental disorder, produced by the same predisposing and exciting causes. The work before us gives a long catalogue of bodily and mental maladies that are known to be common to man and animals. The list includes typhus, yellow fever, puerperal fever, gout, hysteria, mania, idiocy, goitre, asthma, quinsy, and Bright's disease; and he shows that various poisons affect animals in the same way as they affect man.

paper is reprinted from the "Proceedings of the Boston Society of Natural History," 1874. The quasi-volcanic metamorphisms of which it treats are singularly interesting, and here for the first time adequately described. In the "Bad Lands" of the Upper Missouri there exist highly-metamorphosed beds of clays and sands, accompanied by pumiceous and lava-like materials, which closely resemble volcanic products. Still the efficient cause was simply the burning of the underlying beds of lignite. Over hundreds and even thousands of square miles the evidences of these fires are to be seen in the mountain-ridges and buttes. There are frequent indications of the bursting through of these subterranean fires to the surface. Thus we find multitudes of jagged, chimney-like mounds of volcanic brescia. These were little volcanoes, having their seat of action in the burning coal-seam, ten, fifteen, or perhaps fifty feet below. The paper is one of rare value.

round the world are now made with such facility and regularity that the number of those who undertake them is rapidly increasing, while the variety and vivid contrast of the traveler's experiences, as he passes from continent to continent, offer an equal temptation to edify the stay-at-homes with a book describing the tour. A definite round-the-world literature of travel may thus be expected to grow up, and if it all proves to be as pleasant and instructive as Baron de Hübner's book, there will be no reason for regret. The present work is, however, more than an ordinary narrative of observation and traveling adventure. Its author, an Austrian nobleman, a man of culture and with wide experience of character, manners, and institutions, travels as a thinker, as well as a looker-on, and gives to his pages something of the insight of study as well as vivacity of narration. Of course it is impossible to go round the world