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THE POPULAR SCIENCE MONTHLY. 



quent cause to admire the threads which he 

 finds strung across the water-courses, and 

 fastened to the trees on the opposite sides. 

 The threads of these spiders are of dif- 

 ferent kinds, and proceed from different 

 glands. The silk which is wrapped around 

 the cocoons is not the same that is spun in 

 the webs, and may be of an entirely dif- 

 ferent color. The silks of various Epeirce 

 were brought to Europe by travelers in the 

 seventeenth century, and excited admiration 

 by their fineness and brilliancy. Experi- 

 ments were tried in making cloth and gloves 

 from them, but they were found to have 

 no powers of endurance. Louis XIV, wish- 

 ing to encourage a new art, had a coat made 

 of the silk, but was glad to take it off the 

 first day, for it suffered a rent every time 

 he moved. These efforts appear to have 

 been made with the silk of the webs. That 

 unrolled from the cocoons proved to be 

 stronger. M. Bon, in 1709, carded from 

 the cocoons a silk which he described as 

 much finer and stronger than ordinary silk, 

 and which, he claimed, was fitted to make 

 any kind of fabrics. In Spain, Raymondo 

 Maria de Tremezer, between 17V7 and 1791, 

 made several articles as bright and fine as 

 silk from the threads of the Epeira diadcma. 

 Mr. Rolt, an English merchant, was able to 

 exhibit to the Society of Arts a specimen 

 thread twenty thousand feet long, that had 

 been spun by twenty-two spiders in less 

 than two hours, and which was five times 

 as fine as the thread of the silk- worm ! Al- 

 cide d'Orbigny asserted that he had gar- 

 ments, able to sustain considerable wear, 

 made in South America from spiders' silk. 



Food and Civilization. M. Beketoff, a 

 Russian hygienist, has expressed some novel 

 views in a paper on " The Alimentation of 

 the Human Race in the Present and the Fut- 

 ure." Physiologists are accustomed to con- 

 sider a mixed diet, of which meat shall con- 

 stitute about one third, to be the best for 

 mankind in general, and to be almost essen- 

 tial to the best development. M. Beketoff 

 does not consider this view to be well 

 founded, or sustained by the facts as they 

 appear on examination of the diet of the 

 best races. A large majority of mankind 

 do not use meat, nor a mixture of meat and 

 vegetables, but vegetables alone, as food. 



The people of Europe consume more meat 

 than those of any other part of the Old 

 World, but most of it is used in the cities, 

 while the country people enjoy only a small 

 fraction of the quantity which the physiolo- 

 gists say they need, and it has come to that 

 point that, in the most civilized part of the 

 world, meat is only not wholly left out of 

 the list of common foods. In the most 

 populous and most civilized parts of Asia, 

 as in China and India, cattle-raising is quite 

 insignificant, and in Japan can hardly be 

 said to exist at all. The Africans raise cat- 

 tle, but live chiefly on vegetables. Only in 

 North and South America and Australia is 

 meat consumed on a really large scale. Not 

 only the relative, but the absolute number 

 of cattle also, shows a tendency to diminish 

 as the population increases and the ground 

 is more devoted to tillage ; so that the pros- 

 pect is apparent that, with the continuous 

 development of agriculture, industries, civ- 

 ilization, and population, cattle-raising will 

 pass into real insignificance, and the mass of 

 men will be unable to obtain animal food. 

 Sources of vegetable food must be found, to 

 supply its place, among the plants richest 

 in albuminous substances. The legumes 

 are the most prominent of these plants. To 

 determine the power of beans to sustain all 

 the functions of life, Dr. Ylrochiloff per- 

 formed a series of experiments upon him- 

 self, by eating regularly equal quantities of 

 bread and sugar, and adding to them for a 

 certain time meats, for another period peas. 

 The result was, in his own words, that 

 " both the mixtures quite fulfilled the pur- 

 pose of nutrition, as was proved by the 

 same weight of body being kept up and the 

 forces being maintained in the same state 

 by either food." The meat-mixture was, 

 however, assimilated more readily than that 

 of which the peas formed a part. It is 

 affirmed that men occupied in intellectual 

 work especially need a mixed food ; but of 

 this we are not certain, not knowing on 

 what those whose intellectual achievements 

 have been greatest have really lived ; and 

 many of them have been very irregular eat- 

 ers. Taking the historv of the human race 

 as a whole, we may observe that races liv- 

 ing almost exclusively on meat have been 

 and are the most savage ones. The pre- 

 historic " finds " show that the beginnings 



