March 27, 1903.] 



SCIENCE. 



503 



The book is a safe and valuable guide and 

 should prove very useful to health o£B.cers, 

 physicians and all intelligent persons who de- 

 sire to understand the principles of disinfec- 

 tion. There is only one important statement 

 that I take exception to, aiad here the error is 

 on the side of safety. It is stated that disin- 

 fection with the fumes of burning sulphur 

 requires eighteen to twenty-four hours, and 

 that the injurious effect on fabrics of this dis- 

 infectant contracts its use to narrow limits. 



In places where each family occupies an 

 entire house it may be possible to require 

 people to vacate rooms for eighteen hours, but 

 in tenements such as occur in cities this is 

 impossible. We have found, however, that 

 when a room is tightly sealed and four pounds 

 of sulphur are burned to each 1,000 cubic feet, 

 disinfection is practically complete in eight 

 hours, when penetration is not required and 

 the microorganisms to be killed are not more 

 resistant than those met with in diphtheria 

 and small-pox. Its cheapness, ease of use and 

 its value as an insecticide cause us to use sul- 

 phur rather than formaldehyde in the rooms 

 requiring disinfection in the tenements of 

 New York city. 



Wm. H. Park. 



By H. A. MiERS. The Mac- 



millan Co., 8vo. Pp. 584. 



Mr. Miers, for a long time connected with 

 the mineralogical department of the British 

 Museum and now professor of mineralogy in 

 the University of Oxford, has had unusual 

 facilities for the study of mineral specimens, 

 and his book is the result of many years of 

 labor. As stated by the author in his pref- 

 ace, the volume is not an exhaustive system 

 of mineralogy, but is intended rather as a 

 treatise in which students will find all that is 

 required for an elementary acquaintance with 

 the subject. The difficult subjects of mathe- 

 matical crystallography and the physical prop- 

 erties of crystals are treated carefully and 

 with much detail, and the chapter on the op- 

 tical properties of crystals is especially help- 

 ful and suggestive. In the part treating of 

 descriptive mineralogy, comprising about one 

 half of the volume, essentially the same clas- 



sification as adopted by Dana is followed. In 

 tlie description of species the crystallographic 

 characteristics are given with much detail, 

 and the text is illustrated not only by the 

 usual outline figures of crystals, but also by 

 numerous carefully executed and effective 

 shaded drawings, many of them of character- 

 istic specimens in the British Museum. At 

 the close of the volume there are given tables 

 of minerals arranged according to the chem- 

 ical classification, optical properties and spe- 

 cific gravity. 



The book is one which advanced students 

 will find useful in the study and comparison 

 of specimens, but it is scarcely elementary 

 enough to serve as a text-book for beginners. 

 The volume is handsomely gotten up, and in 

 this respect may serve as a model for books 

 of its kind. 



S. L. Penfield. 



SCIENTrFIC JOURNALS AND ARTICLES. 



The American Naturalist for February 

 opens with an important paper on ' The Struc- 

 ture and Relationships of the American 

 Pelycosauria,' by E. 0. Case. The author con- 

 cludes that all known reptiles from the 

 American Permian possessed two temporal 

 arches and that the Pelycosauria followed a 

 line of development here that led to extinc- 

 tion, the persistent line of development being 

 followed elsewhere. These points are dwelt 

 on in a description of the cranial features of 

 various species. V. Sterki presents some 

 ' Notes on the Unionida3 and their Classifica- 

 tion,' and gives a scheme of classification, 

 differing somewhat from that of Simpson, 

 based largely on the structure of the hinge, 

 shape of the embryonic and adult shells, and 

 condition of the marsupia. E. L. Mark de- 

 scribes ' A Paraffine Bath Heated by Elec- 

 tricity,' intended to do away with the danger 

 of explosion that attends the use of gas. The 

 number contains the Quarterly Record of 

 Gifts, Appointments, Eetirements and Deaths. 



The February number of the Botanical 

 Gazette contains the first half of a paper by 

 Dr. E. B. Copeland on ' Chemical Stimula- 



