236 



NATURE 



[July 7, 1892 



cheaper to insure buildings than to incur the expense of erecting 

 lightning-rods, the author quotes a number of authorities in 

 support of the advisability of putting up rods, and gives rules to 

 be observed in doing so. 



Bulletin of the Ntw York Matheviatical Society, vol. i., 

 Nos. 8 and 9 (New York, 1892). — The illustrious German 

 mathematician, Leopold Kronecker, died recently at Berlin 

 (December 29, 1891). No. 8 (pp. 173-84) opens with a most 

 interesting article, by H. B. Fine, entitled "Kronecker and 

 his Arithmetical Theory of the Algebraic Equation." This is 

 biographical and analytical. A short no'e, by Prof. Cajori, 

 follows, on the "Multiplication of Series." The concluding 

 note is by Dr. Macfarlane, " On Exact Analysis as the Basis of 

 Language." This is a brief abstract of a paper read before 

 the Society (March 5, 1892). — No. 9 gives an account of a recent 

 paper in the Mathetnatische Annalen (vol. xxxviii.), by M. Hil- 

 bert, under the head " Topology of Algebraic Curves." The 

 writer, L. S. Hulburt, recasts the theory, with the view of 

 making the theory more intelligible, and corrects some slight 

 inaccuracies. Dr. Merriman abstracts a paper (read before the 

 Society) on "Final Formulas for the Algebraic Solution of 

 Quartic Equations." This number closes with a full account of 

 Poincare's " Mecanique Celeste," by E. W. Brown. The 

 usual short notes and list of new publications are given at the 

 end of each number. 



Meftioirs of the Mathematical Section of the Odessa University, 

 vol. xiii. — On the theory of linear differential equations, by M. 

 Rudzky. — The mechanics of a system subject to similar changes, 

 by D. Seiliger, part iii. The paper is followed by a description of 

 an apparatus, the "homoyograph," three spots of which always 

 take such positions as to make similar triangles. — Experimental 

 researches into the compressibility of glass and mercury, by G. 

 De-Metz. The absolute compressibility of mercury has been 

 determined on the two methods of Regnault and Jamin, as also 

 on a third method which results from the equations of Lame in 

 his " Le9ons sur 1 Elasticite," and the seventh memoir of 

 Regnault. The results arrived at in these very elaborate researches 

 are very near to those arrived at by Amagat. — Volume xii. of 

 the same periodical consists of a work by J. Timtchenko, on 

 the foundations of the theory of analytical functions. The aim 

 of the author is to contribute towards the elaboration of a general 

 theory of functions which would include Weierstrass's theory as 

 well. The first part, now published, contains the historical 

 review of the development of the theory. 



Bulletin de la SociHe des Naturalisles de Moscou, 1891, 

 Nos. 2 and 3. — The Speeton clays and their equivalents, by A. 

 Pavloff and G. W. Lamplugh. — Contributions to the study of 

 molecular forces in chemically simple bodies, on the ground 

 of theimodynamics, by J. Weinberg. — Studies on the develop- 

 ment of Amphipodes, part v., by Madame Catherine Wagner 

 (in French, with two plates). The development of the embryo 

 of the Melita palmata is apparently quite similar to that 

 of Gaminarus and Caprella in its earlier stages, but the 

 microscopic observation of cuttings through the embryo dis- 

 closes several interesting peculiarities, which are described and 

 illustrated. — What is the Hipparion ?, by Marie Pavloff (in 

 French), being an answer to critical remarks, by M. Trouessart, 

 in Annuaire Geologiquc Uniiersel, tome vi., relative to Marie 

 Pavloff's work on the evolution of Ungulates. — On a new 

 apparatus for determining the moment of inertia of a body, by 

 N. Joukovsky (in French). — On Pteromonas alata, Cohn, by 

 M. Golenkin (in German). — The present state of our knowledge 

 of the contents of the cells of the Phycochromaceae, by Valerian 

 Deinega (in German). The author has come to no definite 

 results as to the nucleus in the Phycochromaceae, especially in the 

 thread-like species ; new colouring methods ought to be 

 discovered. 



SOCIETIES AND ACADEMIES. 



London. 



Royal Society, June 2. — " Supplementary Report on 



Explorations of Erect '1 rees containing Animal Remains in the 



Coal-formation of Nova Scotia." By Sir J. William Dawson, 



F.R.S. 



To the memoir which I had the honour to present to the 



NO. I 184, VOL. 46] 



Royal Society on this subject in 1882 ^ I appended a note from 

 Dr. Scudder, of Cambridge, U.S., so well known for his 

 researches in fossil Lisects and Arachnidans, in which he gave a 

 preliminary account of the remains of Arthropods in my collec- 

 tions which I had submitted to him. He has only in the pre- 

 sent year completed his examination of these lemains, most of 

 which are very fragmentary, and much damaged by unequal 

 pressure. The result has been embodied in a Report on 

 Canadian Fossil Insects, now in course of publication by the 

 Geological Survey of Canada. 



In this Report he will describe from the contents of the Sigil- 

 larian slumps extracted by me, with the aid of the grant of this 

 Society, three new species of Myriapoda, making, with the five 

 previously known from ihe>e remarkable repositories, eight in 

 all, belonging to two families, Archiulidas and Euphoberidae, 

 and to three genera, Archiulus, Xylobius, and Amynilysfes. 

 The three new species are Archiulus euphoberioides, Sc, A. 

 Lyelli, Sc, and Amynilyspes (sp.). The remains of Scorpions 

 he refers to three species, Mazonia acadica, Sc, Mazonia (sp.), 

 and a third represented only by small fragments. The charac- 

 ters of the species referred to Mazonia he considers as tending 

 to establish the generic distinctness of Mazonia from Eoscorpius. 

 Dr. Scudder also notices the fragment of an insect's head con- 

 tainini; part of a facetted eye, mentioned in my memoir, and 

 considers it probably a portion of a Cockroach. 



Much credit is due to Dr. Scudder for the care and skill with 

 which he has worked up the mostly small and obscure fragments 

 which I was able to submit to him, and which are probably 

 little more than debris of the food of the Amphibians living 

 for a time in these hollow stumps, and devouring such smaller 

 animals as were so unfortunate as to be imprisoned with them. 

 In this connection the suggestion of Dr. Scudder is worthy of 

 attention, that the scaly armour of the smaller Microsaurians 

 may have been intended to defend them against the active and 

 venomous Scorpions which were their contemporaries, and some 

 of which were sufficiently large to be formidable antagonists to 

 the smaller land Vertebrates of the period« 



The report of Dr. Scudder will complete the account of the 

 land animals of the erect Sigiilarise of the South Joggins, unless 

 by new fails of the cliff fresh trees should be exposed. From 

 1 85 1, when the first remains were obtained from these singular 

 repositories by the late Sir Charles Lyell and the writer, up to 

 the present time, they have afforded the remains of twelve 

 species of Amphibians, three land Snails, eight Millipedes, 

 three Scorpions, and an Insect. 



The type specimens of these animals have been placed in the 

 Peter Redpath Museum of McGill University, and such dupli- 

 cates as are available will be sent to the British Museum and 

 that of the Geological Survey of Canada. 



June 16. — "On the Estimation of Uric Acid in Urine." By 

 F. Gowland Hopkins. 



The process described depends upon the complete insolubility 

 of ammonium urate in saturated solutions of ammonium chloride. 



The pure chloride is powdered, and added to the sample to 

 complete saturation. After two hours' standing, the whole of 

 the uric acid separates as biurate of ammonium. The urate is 

 then decomposed with hydrochloric acid, and the liberated uric 

 acid determined by any approved method. In contrast to the 

 well-known Fokker-Salkowski process the separation is rapid 

 and complete. 



The author has experimented with permanganate solutions 

 for the titration of the separated uric acid, and finds that 

 accurate results may be obtained by their employment. 

 For this purpose the uric acid is dissolved in 100 cc of water, 

 with a minimum of NaaCOg, 20 cc. of strong H^S04 being then 

 added, and the solution immediately titrated with one-twentieth 

 normal permanganate of potassium. The addition of 20 per 

 cent. H2SO., to the previously cooled solution of sodium urate 

 yields just such a temperature (about 6o°C.) as is requisite for a 

 determinate reaction, i cc. of the permanganate solution is equal 

 to 0'00375 grm. uric acid. 



Physical Society, June 24.— Prof. A. W. Riicker, F.R.S., 

 in the chair. — The following communications were made : — On 

 breath figures, by Mr. W. B. Croft. After mentioning the 

 observations of early experimenters on the subject, the author 

 described a method which he found to give the best result.*. A 

 coin is placed on a glass plate for insulation ; another glass plate, 

 which is to receive the impression, is well polished and laid on 



1 Phil. Trans., 1882, p. 621. 



