414 



THE POPULAR SCIENCE MONTHLY. 



compilation of trustworthy patent-lists. Vol- 

 ume I goes from A to Dy. Among its chief 

 articles are those on acetic acid, alcohol, 

 alizarin and allied coloring matters, alu- 

 minium, ammonia, analysis, azo- coloring 

 matters, bleaching, brewing, carbon, ce- 

 ments, chlorine, cyanides, dextrose, disin- 

 fectants, and dyeing. Under alizarin are 

 given the history of the artificial production 

 of this substance, the methods of preparing 

 a large number of derivatives of anthra- 

 quinone, and accounts of the anthraquinone 

 and dichloranthracene processes of manu- 

 facturing alizarin. The article on brewing 

 comprises quite full consideration of the 

 sources and chemical character of the water, 

 barley, and hops used in making beer, with 

 descriptions of the several steps in the pro- 

 cess. Sixteen figures of brewing apparatus 

 are given. In the article on cements, both 

 building cements and adhesive cements are 

 treated. Under the former division are in- 

 cluded hme-burning, mortar, plaster of Paris, 

 hydraulic mortar, pozzuolana, hydraulic ce- 

 ment, oxychloride cements, artificial stone, 

 and concrete. Analyses of many of these 

 substances are given in tables, and a bibli- 

 ography of the subject is appended. Many 

 of the articles involving descriptions of ap- 

 paratus are fully illustrated. The more im- 

 portant ones are signed, and a list of con- 

 tributors to the volume is prefixed, among 

 which may be found many well-known 

 names. 



Gems and Precious Stones op North Amer- 

 ica. By George Frederick Kcnz. Il- 

 lustrated with Eight Colored Plates and 

 numerous Minor Engravings. New York : 

 The Scientific Publishing Company. Pp. 

 336. Large 8vo. Price, $10. 



Mr. Kunz has written a very interesting 

 book, and it has been published in an ele- 

 gant style. Nearly all the known varieties of 

 precious stones occur in North America, and 

 many of the American specimens have much 

 beauty, but they are not found of such size 

 and quality nor in sufficient quantity to rank 

 them as an important product of the coun- 

 try. About one hundred thousand dollars' 

 worth of precious stones, including pearls, 

 are found in the United States yearly, but 

 this is less than the value of the output from 

 the diamond-mines of South Africa, or from 

 our coal and iron mines, for a single day. 



The occurrence of diamonds in the United 

 States, Mr. Kunz tells us, is chiefly confined 

 to two belts of country : one along the east- 

 ern base of the Alleghanies, from Virginia 

 to Georgia ; the other along the western base 

 of the Sierra Nevada and Cascade Ranges in 

 Oregon and northern California. The Dewey 

 diamond, found at Manchester, Va., in 1855, 

 weighed before cutting 23| carats, and 11-^- 

 carats afterward. It passed through sev- 

 eral hands, becoming the property of John 

 A. Morrissey, who had made a loan of six 

 thousand dollars on it. As it is off-color 

 and imperfect, it is to-day worth not more 

 than three or four hundred dollars. Mr. 

 Kunz gives the history of the finding of a 

 number of other American diamonds, many 

 of which were picked up by children, or by 

 persons knowing nothing of mineralogy. 

 Some of these were destroyed by being struck 

 with a hammer, their finders having an idea 

 that this was a test which a diamond ought 

 to stand. He also tells of reported finds of 

 diamonds in which the stone turned out to 

 be a quartz crystal which had been rolled 

 among the gravel of some stream till it had 

 acquired the appearance of a rough diamond. 

 Pieces of blue glass similarly worn into 

 the shape of pebbles have been taken for 

 sapphires. The largest crystal of sapphire 

 ever found is in the Shepard mineral collec- 

 tion at Amherst College. It weighs three 

 hundred and twelve pounds, is a perfectly 

 terminated prism, partly red and partly blue 

 in color, but opaque. It was obtained by Mr. 

 C. W. Jenks from his mine at Franklin, N. C. 

 In his chapter on the turquoise Mr. Kunz tells 

 of its use by the ancient Mexicans, and by 

 the Indians of the Southwestern United St? ,es, 

 and gives pictures of several ornaments of 

 their workmanship. He tells where the ruby, 

 topaz, and emerald are found, and where 

 occur a large number of less valuable stones, 

 such as the garnet, tourmaline, beryl, ame- 

 thyst, opal, agate, jasper, silicified wood, la- 

 pis lazuli, moonstone, sunstone, obsidian, am- 

 ber, jet, cat's-eye, serpentine, malachite, and 

 very many more whose names are less familiar. 

 His account of Chalcedony Park in Arizona, 

 where there are great blocks and whole tree- 

 trunks turned to agate, is a very interesting 

 portion of the book. There is also a remark- 

 ably attractive and fully illustrated chapter 

 on pearls. The chief pearl-fishing grounds 



