May 28, 1891] 



NATURE 



89 



time ; the nomenclature of each species has been critically re- 

 vised and brought up to date. Careful attention has also been 

 paid to the relationship between recent and Tertiary forms. 

 The generic names under which most of the shells are still 

 known in this country are added as an assistance to the student. 



The Physical Society of London has published the first part 

 of the eleventh volume of its Proceedings. Among the contents 

 are notes on photographs of rapidly moving objects, and on the 

 oscillating electric spark, by Mr. C. V. Boys ; a formula for 

 calculating approximately the self-induction of a coil, by Prof. 

 John Perry ; a lecture experiment illustrating the effect of heat 

 upon the magnetic susceptibility of nickel, by Mr. Shelford 

 Bidwell ; and experiments in photo-electricity, by Prof. G. M. 

 M inch in. 



A LECTURE by Prof A, Macalister, delivered on January 29, 

 on the opening of the new anatomical lecture-room at Cambridge, 

 has been published by the Cambridge University Press. The 

 subject is "The History of the Study of Anatomy in Cam- 

 bridge. " 



Messrs. Charles Griffin and Co. have published the 

 eighth annual issue of the "Year-book of the Scientific and 

 Learned Societies of Great Britain and Ireland." The work is 

 compiled from official sources, and comprises lists of the papers 

 read during 1890 before Societies engaged in fourteen depart- 

 ments of research, with the names of their authors. 



The Engineering Company, publishers. New York, are 

 issuing a new monthly magazine, entitled Engineering, which is 

 to be wholly devoted to the record of industrial progress. The 

 first two numbers have been published. 



There are some valuable morphological notes in the Johns 

 Hopkins University Circulars for May. Among other papers 

 we may mention one on the structure and development of the 

 gonophores of a certain Siphonophore belonging to the order 

 Auronectse (Haeckel), by \V. K. Brooks and E. G. Conklin. 

 Other papers are : preliminary notes on some new species of 

 Squilla, by R. P. Bigelow, and a preliminary note on the 

 anatomy and transformation of Tornaria, by T. H. Morgan. 



The " Bibliotheque Evolutioniste " is the general title of a 

 new scientific series which is being published in Paris. The 

 editor is M. Henry de Varigny. The first volumes are mostly 

 translations, Wallace's "Darwinism" opening the list; but 

 French authors are also to contribute, and works are being pre- 

 pared by Messrs. A. Sabatier, of Montpellier ; J. Deniker, the 

 well-known anthropologist ; Prof. Giard, and others. 



In Nature for May 14, p. 36, line 5 from top, or " 1887" 

 read "1889." 



A NEW and very beautiful silver mineral is described by Mr. 

 F. A. Genth in the May number of the American Journal of 

 Science. It was discovered by SeRor Aguilar, of the San Carlos 

 Silver Mine at Guanajuato, Mexico, and has been named after 

 him, aguilaiite. It is a sulpho-selenide of silver, of the composi- 

 tion AgjS -(- AgjSe, the analyses of pure crystals agreeing 

 exactly with this formula. The crystals are iron-black in 

 colour, and possess a most brilliant lustre. They belong to 

 the cubic system, and consist of curious skeleton dodecahedrons, 

 the edges of which are perfect, while the centres of the faces are 

 more or less wornor imperfectly developed. These dodecahedrons 

 are frequently elongated in such a manner as to resemble either 

 tetragonal prisms terminated by pyramids of the opposite order, 

 or hexagonal prisms terminated by rhombohedral planes. They 

 generally occur in interlaced and closely aggregated groups, the 

 individual crystals of which attain a size of a centimetre or more 

 in diameter. They are for the most part embedded in colourless 



NO. I I 26, VOL. 44] 



calcile, which may readily be removed from them by means of 

 dilute acetic acid ; frequently a little quartz is associated with 

 them. The crystals are readily sectile and malleable, and their 

 hardness is only 2 '5, Their specific gravity is 7 "586. When 

 heated in an open tube to low redness, gradually increasing to 

 bright redness, they yield metallic silver, together with a slight 

 sublimate of selenium, and slender needles of selenious and 

 sulphuric oxides, which latter forms, with a little of the silver, 

 silver sulphate. In many of the specimens of aguilarite examined, 

 the crystals were observed to be penetrated in a remarkable 

 manner by round holes, and they also frequently exhibited 

 deposits of pure metallic silver upon their faces. 



Several of the simpler sulphides of the organic radicles have 

 been found to occur naturally in the crude petroleum oil of Ohio 

 by Messrs. Mabery and Smith, who describe the mode adopted 

 for their isolation in the current number of the American 

 Chemical Journal. As far as they are aware, these alkyl 

 sulphides have never previously been found in nature. When 

 the higher boiling fractions of the distilled oil are agitated with 

 oil of vitriol, these sulphur compounds are taken up by the 

 sulphuric acid, and, upon subsequently neutralizing the acid 

 solution with slaked lime, unstable calcium salts are obtained, 

 which are readily decomposed by distillation in steam, which 

 carries over the sulphides without decomposition. By employing 

 these reactions upon a large scale, and afterwards subjecting 

 the mixed sulphides to a rigorous fractional distillation under 

 reduced pressure (150 mm. being the most convenient working 

 pressure), the following sulphides have been isolated : methyl 

 sulphide, (CH3)2S ; ethyl sulphide, (C2H5)2S ; normal propyl 

 sulphide, (C3H-)2S ; normal and iso-butyl sulphides, (C4H9)2S -, 

 amyl sulphide, (C5Hji)2S ; hexyl sulphide, (CeHi3)2S ; and a few 

 other sulphides of mixed radicles. Most of these sulphides were 

 obtained in the pure state by treating the products of the frac- 

 tionation with mercuric chloride, and thus obtaining crystals of 

 the addition compounds of the type (CHjjoS . HgCL, and sub- 

 sequently decomposing these crystals of the mercury compounds 

 with sulphuretted hydrogen. 



The additions'to the Zoological Society's Gardens during the 

 past week include a Barbary Ape {Macacus inuus S) from 

 North Africa, presented by the Rev. G. H. Watkins ; a Diuca 

 Finch {Diuca grisea), two Gay's Finches {Phrygilus gayi) from 

 Chili, two De Filippi's Meadow Starlings {Sturnella defilippi) 

 from La Plata, presented by Mr. Charles G. Sharpe ; two Bankiva 

 Jungle Fowls {Gallus bankiva S 9 ) from India, presented by 

 Captain George James ; a Common Rhea {Rhea americana) 

 from South America, presented by Mr. R. P. Houston; an 

 Algerian Tortoise {Testudo maurilanica) from North Africa, 

 presented by Mrs. Margaret Clarke ; a Black-eared Marmoset 

 {Hapale penicillata) from South-east Brazil, presented by Mr. 

 Aubrey Lace ; a Capybara {Hydrocharus capybara), a Brown 

 Milvago {Milvago chimango), a Violaceous Night Heron {Nycti- 

 corax violaceus) from South America, two Blue-bearded Jays 

 {Cyanocorax cyanopogon) from Para, four Crested Screamers 

 {Chauna chavaria) from Buenos Ayres, deposited ; two Varie- 

 gated Sheldrakes {Tadorna variegata) from New Zealand, two 

 Larger Tree Ducks (Dendrocygna major) from India, purchased ; 

 two Japanese Ueer {Cervus sika <J ? ), a Chinchilla {Chinchilla 

 lanigera), an African Wild Ass (Equus tceniopus), born in the 

 Gardens. 



OUR ASTRONOMICAL COLUMN. 

 The Draper Catalogue of Stellar Spectra.— Vol. 

 xxvii. of the Annals of the Astronomical Observatory of Harvard 

 College contains a catalogue of the spectra of 10,351 stars, nearly 

 all of them north of the parallel of declination - 25°, photo- 

 graphed with the 8- inch Bache telescope. As the work forms a 



