December 24, 1891] 



NATURE 



185 



bottle of water, in which there was a good supply of the organ- 

 ism in question. At first he thought it was a species of the genus 

 Peridiniidae ; but further research convinced him that it was a 

 new species of the closely allied genus, Glenodinium. So far 

 as Mr. Whitelegge is able to judge, fully one-half of the shore 

 fauna must have been destroyed by these small invaders. The 

 bivalves were almost exterminated in those localities where the 

 organism was abundant during the whole of the visitation. Mr. 

 Whitelegge is of opinion that the great destruction of life 

 brought about by an organism apparently so insignificant is 

 of the highest interest from a biological point of view, showing, 

 as it does, how limited is our knowledge of the causes which 

 influence marine food-supplies. This, he points out, is par- 

 ticularly the case in regard to the oyster, which has often mys- 

 teriously disappeared from localities where it formerly abounded. 



The U. S. Department of Agriculture has published the fifth 

 number of a series of papers on the North American fauna. 

 The number contains the results of a "biological reconnois- 

 sance " of a part of Idaho, which Dr. C. Hart Merriam con- 

 ducted during August, September, and October 1890 ; and also 

 descriptions of a new genus and several new species of North 

 American mammals. The new genus (Microdipodops) is a kind 

 of dwarf kangaroo rat from Nevada. Dr. Merriam speaks of 

 this as one of the most remarkable of the many new and inter- 

 esting mammals discovered in North America during the past 

 few years. Six specimens were collected in Nevada by Mr, 

 Bailey in October and November 1890. 



It is most important that members of the medical and 

 scholastic professions, and the public generally, should have 

 sound ideas on the best means for guarding great educational 

 establishments from the outbreak and spread of preventible in- 

 fectious and contagious disease. We are glad to note, therefore, 

 that the code of rules on the subject, drawn up by the Medical 

 Officers of Schools Association, has been so much in demand 

 that it has been necessary for Messrs. J. and A. Churchill, the 

 publishers, to issue a third edition. An important note to an 

 appendix in which disinfection is dealt with has been added in 

 this edition. The measures indicated in the appendix have 

 hitherto been regarded as at least serviceable for the attainment 

 of disinfection. Recent experiments, however, seem to show 

 that none of them can be relied upon as absolutely effectual in 

 certain cases. 



At the meeting of the Field Naturalists' Club of Victoria, on 

 October 12, Mr. J. P. Eckert read a paper on "some peculiar 

 changes in the colour of the flower of Swainsonia procumbens." 

 When the flower opens, the corolla is lilac, and the first change 

 is noticed in the longitudinal venules of the largest petals, which 

 soon after assume a deep crimson. Then, at two different 

 points of the petals a dark blue is noticed, which gradually 

 extends over the whole surface, the peripheral portion being a 

 little paler in colour. In the central portion the colour varies 

 through all the shades of blue till finally it assumes a rosy tint. 

 Frequently the petals will assume their original colour for some 

 days, and afterwards go through all the gradations of colour 

 once more. Mr. Eckert assigns the phenomena to a meteoro- 

 logical cause, and claims that his theory is supported by experi- 

 ments with the electric current. 



The New York Engineering News says that prehistoric 

 irrigation canals in Arizona are "really worthy of more notice 

 than is usually given them. The Salt and Gila River valleys are 

 intersected by a vast network of these canals, which antedate, 

 at least, the arrival of Coronado in 1552, for he mentions these 

 ruins and the traditions of the Indians regarding a once dense 

 population in this region. Modern engineers cannot improve 

 upon the lines of these canals, nor in the selection of points of 

 NO. II 56. VOL. 45] 



diversion from the rivers. The first irrigation canal in thb 

 section, the one that has made Phoenix, with its present popula- 

 tion of 20,000, simply followed the lines of one of these old 

 canals. Their extent may be appreciated when it is said that in 

 the Salt River valley alone the land covered by these canals once 

 aggregated over 250,000 acres, and the canals themselves, with 

 their laterals, must have exceeded 1000 miles in length. This 

 country is filled with prehistoric ruins, with walls of stone or 

 adobe, and almost every acre contains fragments of pottery, 

 steel ornaments, stone implements, and other remains of a 

 population which can only be estimated in its aggregate." 



The fifth part of "Bibliotheca Mathematica," edited by G. 

 Enestrom'(Stockholm), is devoted to a bibliography of the history 

 of the mathematical sciences in the Netherlands, by D. Bierens 

 de Haan, of Leyden, By the conditions of the publication the 

 writer is restricted " aux ecrits se rapportant exclusivement ou 

 au moins essentiellement a I'histoire des mathematiques pures.'* 

 In ten octavo pages the list ranges from 1667 to the present time, 

 and contains sixty entries, the compiler being credited with 

 thirteen of them. There is also a long list of Sloges on Dutch 

 mathematicians. 



We have received from Mr. Elliot Stock the second volume 

 of The Field Club. It is a magazine of general natural 

 history, and cannot fail to give pleasure to readers who are 

 interested in the results of scientific observation. The editor 

 is the Rev. Theodore Wood. 



The new number of the Economic Journal (vol. i. No. 4) 

 deals with various questions which are of great scientific interest 

 as well as of urgent public importance. It opens with an intro- 

 ductory lecture on political economy, by Prof. F. Y. Edge- 

 worth, the editor. Then come papers on the alleged diflfer- 

 ences in the wages of men and women, by Sidney Webb ; the 

 coal question, by Forster Brown ; the new theory of interest, 

 by W. Smart ; the evolution of the Socialist programme in 

 Germany, by Prof. G. Adler ; labour troubles in New Zealand, 

 by W. T. Charlewood ; and an attempt to estimate the circula- 

 tion of the rupee, by F. C. Harrison. 



The January number of Mind, the first of the new series, 

 will contain articles by Mr. W. E. Johnson on " Symbolic 

 Logic," by Mr. Alexander on the " Idea of Value," by Mr. 

 McTaggart on the "Change of Method in Hegel's Dialectic," 

 and by Prof Lloyd Morgan on the " Law of Psychogenesis." 



The arrangements for science lectures at the Royal Victoria 

 Hall during January are as follows .—January 12, Sir Herbert 

 C. Perrott (Chief Secretary of the St. John's Ambulance 

 Association), " First Aid to the Injured: its object, origin, and 

 development " (this lecture will be followed by an ambulance 

 class in the Morley Memorial College) ; 19, Mr. Locke Worth- 

 ington, "Egypt 3000 years ago." On the 26th, Prof Reinold 

 will deliver a lecture. 



Two new methods of preparing free solid hydroxylamine, 

 NHjOH, are described by M. Crismer in the current number of 

 the Bulletin de la Sociiti Chimique. It will be remembered 

 that this important substance was isolated a few weeks ago by 

 M. Lobry de Bruyn ; an account of the manner in which it was 

 obtained, together with a description of the dangerous properties 

 of the free base, was given in Nature (p. 20). M. Crismer 

 now publishes two very simple methods of isolating anhydrous 

 hydroxylamine, by the use of a compound of hydroxylamine 

 and zinc chloride, previously described by him (comp. Nature, 

 vol. xli. p. 401). This interesting compound is a crystalline 

 substance, of the composition ZnClj . 2NH2OH, readily pre- 

 pared in large quantity by dissolving the hydrochloride o 



