374 KANSAS CITY REVIEW OF SCIENCE. 



It is now evident that the basins of the East Fork of the Yellowstone, Peli- 

 can, Tower, and Black Tail Creeks, constitute a region of fossil forests where an 

 excavation or erosion at an elevation of from 7,000 to 10,000 feet would most 

 lilely unearth the fossilized branches, trunks, and roots of the giant trees of some 

 primeval forest. Whether the successive deposits now encasing these forests in 

 some portions of the Park to a vertical depth, of at least 4,000 feet are subaquous 

 or subaerial, or, as is probable, partly both, it is evident that great and long-con- 

 tinued oscillation of the surface and periods of submergence and elevation have 

 occurred, as the roots of the fossil trees of these forests, little inferior in size to 

 the "big trees" of California, often penetrate nearly, if not quite, through the 

 horizontal stratum or layer of earth and rock upon which they grew, into the 

 broken, shattered, and eroded trunks of the fossil trees beneath them. It is also 

 evident, from the uniform character of the successive forests in vertical layers 

 that the agents or influences for fossilization were for an immense period of time 

 uniform and abundant, while those for crystalizing, though long continued, were 

 at no period so abundant or uniformly distributed. In fact, it is not usually the 

 largest trees, or forests of them, which are other than simply fossilized in the 

 original forms of the timber but, rather, limited areas of usually smaller and more 

 scattermg timber, originally cnncealed in the peculiar cements which fills every 

 crack and cavity, not only of the wood but also of the incasing rocks and their 

 interstices, with the most beautiful chalcdony, which, probbaly, after long-contin- 

 ued processes of cooling, has produced the famous caskets of brilliant amethysts 

 and other crystals here found, and which, while elsewhere unequaled in nature, 

 are considered inimitable by art. — U. S. Geo. Rep. 



MEDICINE AND HYGIENE. 



THE ATTENUATION OF VIRUS. 



So long as vaccination stood alone, the alleged prevention of a malignant 

 disease by the voluntary production of a mild disease of similar type being a fact 

 unique and unexplained, the anti-vaccinationists had a shadowy ground to stand 

 on. How is it possible, they asked, to protect life and health by inviting dis- 

 ease ? And when they boldly disputed statistics and pronounced the theory of 

 vaccination a delusion, not a few intelligent people were confounded and preju- 

 diced against a practice which has reduced to comparative feebleness one of the 

 worst of the plagues of former days. 



The discoveries made last year by Professor Pasteur in connection with 

 chicken cholera, and fully described in this paper at the time, made vaccination 

 a fact no longer unique, and gave a most promising clew to the rationale of its 

 operation in making the system less vulnerable to small-pox. As our readers 



