Page:Popular Science Monthly Volume 24.djvu/444

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THE POPULAR SCIENCE MONTHLY.

tion. From the search for supernatural means of driving away the evil spirits supposed to be working harm to the child have arisen very curious and wide-spread doctrines which are of great value in the history of customs. The little being who has come into the world is not always believed to be pure, and to have a clear right to existence. Many peoples regard it as "unclean" and not to be touched for a certain time. Others require it to be expressly recognized by the father; and some give the parents a right to expose or kill it immediately. Among most people it is considered essential to perform some kind of ceremony for formally adopting the child into the family and society. Such ceremonies are generally dietetic, or relate to washing and bathing, anointing the skin, giving the first food, circumcision, putting on clothing, or cutting the hair, and are observed as important mysteries favorable to bodily endurance and mental vigor. Here we approach the transition from the instinctive hygiene of popular customs to religious ceremonies. Survivals of the notions here pointed to are traced by Herr Ploss among popular customs that have not yet died out in the more retired districts of Europe.

 

Use of Salt.—Among other follies of the day, some indiscreet persons are objecting to the use of salt, and propose to do without it. Nothing could be more absurd. Common salt is the most widely-distributed substance in the body; it exists in every fluid and in every solid; and not only is it everywhere present, but in almost every part it constitutes the largest portion of the ash when any tissue is burned. In particular, it is a constant constituent of the blood, and it maintains in it a proportion that is almost wholly independent of the quantity that is consumed with the food. The blood will take up so much and no more, however much we may take with our food; and, on the other hand, if none be given, the blood parts with its natural quantity slowly and unwillingly. Under ordinary circumstances, a healthy man loses daily about twelve grains by one channel or the other, and, if he is to maintain his health, that quantity must be introduced. Common salt is of immense importance in the processes ministering to the nutrition of the body, for not only is it the chief salt in the gastric juice, and essential for the formation of bile, and may hence be reasonably regarded as of high value in digestion, but it is an important agent in promoting the processes of diffusion, and therefore of absorption. Direct experiment has shown that it promotes the decomposition of albumen in the body, acting, probably, by increasing the activity of the transmission of fluids from cell to cell. Nothing can demonstrate its value better than the fact that, if albumen without salt is introduced into the intestine of an animal, no portion of it is absorbed, while it all quickly disappears if salt be added. If any further evidence were required, it would be found in the powerful instinct which impels animals to obtain salt. Buffaloes will travel for miles to reach a "salt-lick"; and the value of salt in improving the nutrition and the aspect of horses and cattle is well known to every farmer. The popular notion that the use of salt prevents the development of worms in the intestine has a foundation in fact, for salt is fatal to the small threadworms, and prevents their reproduction by improving the general tone and the character of the secretions of the alimentary canal. The conclusion, therefore, is obvious that salt, being wholesome, and indeed necessary, should be taken in moderate quantities, and that abstention from it is likely to be injurious.—Lancet.

 

Intelligence of a Turret-Spider.—The nest of the Tarentula arenicola, or American turret-spider, is a vertical tube, extending twelve or more inches into the ground, and projecting half an inch to an inch above the surface. The projecting portion, or turret, is in the form of a pentagon, more or less regular, and is built up of bits of grass and straw, small twigs, etc., cemented with mud, like a miniature old-fashioned chimney. The upper part of the tube has a thin lining of web-silk. A nest was exhibited by Vice-President H. C. McCook, D. D., at a meeting of the Academy of Natural Sciences, of Philadelphia, which, during its journey from Vineland, New Jersey, where it was found, had been plugged at top and bottom with cotton. Upon the arrival of the nest in Philadelphia, the plug guarding the en-