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THE POPULAR SCIENCE MONTHLY. 



blocks, when M. Rathelot hit upon the fol- 

 lowing method of operation : In the first 

 place, he cut off the back of the book so as 

 to leave nothing but a mass of leaves, which 

 the fire had caused to adhere to each other. 

 He then steeped the book in water, and af- 

 terward exposed it, all wet as it was, to the 

 heat at the mouth of a calorifere ; the wa- 

 ter, as it evaporated, raised the leaves, one 

 by one, and they could be separated, but 

 with extraordinary precautions. Each sheet 

 was then deciphered, and the copy certified 

 by a legal officer. In this way the records 

 of nearly 70,000 official acts have been 

 saved. The appearance of the pages was 

 very curious the writing appeared of a 

 dull black, while the paper was of a lus- 

 trous black, something like velvet decora- 

 tions on a black-satin ground, so that the 

 entries were not difficult to read. 



Sonorous Sand. There was recently 

 presented to the California Academy of 

 Sciences, by W. R. Friuk, of Honolulu, a 

 specimen of " sonorous sand " from the 

 island of Kauai, one of the Hawaiian group. 

 In a letter accompanying the specimen, Mr. 

 Frink states that the bank from which this 

 sand was taken commences at a perpen- 

 dicular bluff at the southwest end of the 

 island, and extends a mile and a half almost 

 due south, parallel with the beach, which 

 is about 100 yards distant from the sand- 

 bank. The latter is about sixty feet high, 

 and is constantly extending to the south. 

 At the extreme south end, and for half a 

 mile north, if you slap two handfuls of the 

 sand together, a sound is produced like the 

 hooting of an owl. If a person kneels on 

 the steep incline, and then, with the two 

 hands extended and grasping as much sand 

 as possible, slides rapidly down, carrying 

 all the sand he can, the sound accumulates 

 till it is like distant thunder. " But the 

 greatest sound we produced," says Mr. 

 Frink, " was by having one native lie upon 

 his belly, and another take him by the 

 feet and drag him rapidly down the in- 

 cline. With this experiment the sound 

 was terrific, and could have been heard 

 many hundred yards away." 



The sand of Jebel Nagus, a hill lying to 

 the west of the mountain usually called i 

 Sinai, in Arabia, possesses similar proper- 



ties. According to Captain H. S. Palmer, an 

 English traveler, it gives out musical sounds 

 whenever it is set in motion. The sound 

 produced " is neither metallic nor vibra- 

 tory. It might be compared to the sharp- 

 est notes of the iEolian harp, or to the 

 sound caused by forcibly drawing a cork 

 over wet glass. When at the maximum 

 intensity it may be heard at a considerable 

 distance." 



Dr. James Blake, of the California Acad- 

 emy of Sciences, has investigated with the 

 microscope the structure of the Kauai sand, 

 and states that the grains are chiefly com- 

 posed of small portions of coral, and ap- 

 parently calcareous sponges. They are all 

 more or less perforated with small holes, 

 mostly terminating in blind cavities, which 

 are frequently enlarged in the interior, 

 communicating with the surface by a small 

 opening. The structure of the grains, Dr. 

 Blake thinks, fully explains the reason 

 why sounds are emitted when they are set 

 in motion. The mutual friction causes vi- 

 brations in their substance, and conse- 

 quently in the sides of the cavities ; and, 

 these vibrations being communicated to 

 the air in the cavities, the result is sound. 

 There are, in fact, millions upon millions of 

 resonant cavities, each giving out a sound 

 which may well acquire a great volume, 

 and even resemble a peal of thunder. 

 The sand must be dry, however, in order 

 to produce sound ; for, when the cavities 

 are filled with water, the grains are inca- 

 pable of originating vibrations. 



Frof. Wurtz on the Order of Nature. 



Prof. Ad. Wurtz, in his address as President 

 of the French Association, referred as follows 

 to the ultimate questions of science : " With 

 regard to matter, it is ever and everywhere 

 the same, and the hydrogen of our earth's 

 water we trace in our sun, in Sirius, and 

 in those nebulae which are still unformed 

 worlds. Everywhere is motion, too ; and 

 motion, which appears inseparable from 

 atoms which constitute matter, is the origin 

 of all physical and chemical force. Such is 

 the order of Nature ; and the deeper Sci- 

 ence searches into her mysteries, the more 

 clearly it evolves the simplicity of the 

 means used, and the infinite diversity of 

 results. Thus, from under the edge of the 



