Geology and Mineralogy. 245 



Washington, 1891. — Mr. Scudder's bibliography takes up sep- 

 arately the Paleozoic species, Mesozoic and Cenozoic and gives 

 the references in the briefest form, and still 100 pages are devoted 

 to the Paleozoic species alone, 180 to the Mesozoic, and 500 to 

 the Cenozoic species : so that altogether the entries make a 

 volume of 744 pages. 



6. On the removal of gold from suspension and solution by 

 Fungoid growths. — Prof. A. Liversidge, of Sydney, N. S. W., 

 states in a paper read before the Australasian Association for the 

 Advancement of Science at Melbourne in 1890, that, he first ob- 

 served in 1889 that gold was removed f i om solution and suspen- 

 sion by fungoid growths, and had since made further investiga- 

 tions. The gold was held in suspension in distilled water, that 

 had been prepared at different times, the gold being reduced from 

 a weak solution of the chloride by means of phosphorus dissolved 

 in ether. A complete precipitation usually takes several years. 

 Examining the bottles which had been settling since 1881, he 

 found that in those having fungoid growths, usually at the bot- 

 tom of the bottles, the liquid was colorless, but in the others the 

 eolor was ruby-red or purple, the gold being still in suspen- 

 sion. In one bottle put up in November, 1884, having the liquid 

 colorless, a purple-blue iungoid growth had taken place, which 

 under the microscope was a mass of matted purple-blue filaments ; 

 but after being dried over a spirit lamp, the filaments retained their 

 form but acquired the luster and color of gold. In 1889, other 

 experiments were tried with more precise results. But it was 

 found that not only moulds produce the res.dt, but also any 

 organic matter living or dead. 



7. Les Methodes de Synthase en Mineralogie par Stanislaus 

 Meunier. 359 pp. 8vo. Paris, 1891. — The progress made in the 

 subject of mineral synthesis has been remarkably rapid in the 

 last two decades, and the success of the French chemists in this 

 line has been particularly marked. The excellent books of 

 Fouque and Levy (1882) and of Bourgeois (1884), which gave a 

 full summary of what had been accomplished in the way of form- 

 ing artificial minerals, are now followed by a volume by another 

 active worker in the same field, Stanislaus Meunier. This work, 

 however, occupies a place of its own, for it is devoted particularly 

 to an explanation of the methods used and general principles 

 involved. The first part discusses the contemporaneous formation 

 of minerals in nature ; and a second part is given to the cases of 

 accidental synthesis, furnace products, etc. The third and most 

 important division describes the method of synthesis proper ; first 

 by the dry way involving simple crystallization by molecular 

 change, by igneous fusion and by the intervention of a miner- 

 alizer ; then simple decomposition ; chemical union ; precipitation 

 and finally, double decomposition. The methods of synthesis in 

 the wet way are also described with similar system and thorough- 

 ness as also those where the method is mixed. This summary 

 will give an idea of the wide range of topics here presented, but 

 the volume calls for the close study that it fully merits. 



