76 



NATURE 



{May 24, 1877 



intensity of its illumination, and he pointed out that an object 

 always appears larger when looked at with two eyes than with 

 one eye. — Mr. Roberts drew attention to the fact that the system 

 ordinarily adopted in mechanical drawing of a'lsuming the light 

 to fall from the left hand top-corner gives an appearance of 

 solidity, whereas if this be reversed, and the light falls from the 

 right-hand bottom corner the object appears hollow. — The pre- 

 sident referred to the well-known fact that if two stereoscopic 

 pictures are taken, representing the same object in complemen- 

 tary colours, most people have a great difficulty in comljining 

 them so as to see a single picture of a ntutral tint. — Mr. S. P. 

 Thompson then described a curious observation of change of 

 pitch occurring when a tuning-fork is caused to rotate rapidly 

 round its axis ; the nodal interferences at each quarter rotation 

 ceasing to be separately heard when recurring more than about 

 thirty times in a second. He has attempted various ways of 

 estimating the amount of this change of pitch, including a 

 method founded on the binaural estimation of interference beats. 



Institution of Civil Engineers, May 8 and 15. — Mr. 

 George Robert Stephenson, president, in the chair.— A paper 

 bySirG. W. Armstrong, C.B, F.R.S., V.P. Inst. C.E., on 

 the history of the modern development of water-pressure ma- 

 chinery was read. 



Cambridge 



Philosophical Society, May 7. —Prof. Clerk Maxwell, presi- 

 dent, in the chair. — Mr. J. W. L. Glaisher read a paper on ex- 

 pressions for the theta functions as definite integrals. — Mr. 

 Warren's fourth "Exercise in Curvilinear and Normal Co- 

 ordinates" was presented to the Society by Prof. Cayley, and 

 will appear in the next issue of the Society's Transactions. 



Paris 

 Academy of Sciences, May 14. — M. Peligot in the chair. — 

 The following papers were read : — Isoperimetric triangles having 

 one side of constant size and the summit atja fixed point, by M. 

 Chasles. — Rot.alory action of quartz on the plane of polarisation 

 of obscure calorific rays, by M. Desains. He has examined the 

 action of six groups of dark rays of decreasing refi;angibility. 

 The law of thicknesses still applies to tlie least refrangible rays. 

 In the symmetrical dark region of nearly extreme violet the 

 polarised heat is so little sensible to the action of quartz that 

 transmission through a plate 0015 m. thick, gives hardly a rota- 

 tion of 5 degrees, or J degree per millimetre. This is 132 times 

 less than for the violet of M. Biot's table. M. Desains de- 

 scribes his apparatus fully. — Analysis of an ancient wine, pre- 

 served in a glass vessel sealed by fusion, by M. Berthelot. This 

 was found on the site of an old Roman cemetery near Aries, 

 and probably dates back some sixteen hundred years. — Analysis 

 showed in a litre, 45 c c. alcohol, 3 '6 gr. fixed acids, 0'6 

 bitartrate of potash, 1'2 acetic acid. There were [also 

 tartrate of lime and traces of acetic ether. It is a weakly 

 alcoholic wine, which must have entered on acetification before 

 being put in the tube. — M. Senet presented tome vii. of the 

 " Cl'^uvres de Lagrange," completing the series. — On the new 

 navigation, by M. ^'illarceau. — On the origin and nature of the 

 fever called typhoid, by M. Guerin. The object of this third 

 memoir is to show that the toxical principle produced by ster- 

 coral fermentation causes what are looked on as the anatomical 

 characters of the fever. M. Guerin has proved that the liquids 

 specially poisonous are those which accumulate near the end of 

 the ileum, and are permanently retained by theileo-crecal valve. 

 The poison passes into the mesentery and to the ganglions con- 

 tained in it— New exposition and generalisation of the method 

 of Gauss for calculatnig approximately a definite integral, by 

 M. Pujet. — New meteorological maps of the South Atlantic, 

 giving at once the direction and the intensity of the winds, by 

 M. Brault. The general movement of the summer winds 

 there is that of an immense cyclone with its centre about 

 30° or 35° south latitude, and 10° or 20° west longitude. It turns 

 in opposite directions to the hands of a watch, and gives 

 off the south-east trades towards Africa, &c. There is not a zone 

 of tropical calms, nor a zone of weak and arbitrary breezes. — 

 On a new type of simple monstrosity, omphalocephaly or umbili- 

 cal hernia of the head, by M. Dareste. The head seems to 

 come from the aperture of the umbilicus. The form has been 

 observed in the hen, but not in man or mammalia. — Experiments 

 made at the vitreolar station of Cognac with the view of finding 

 an efficacious remedy against phylloxera, by M. Mouillefert. 

 This is in favour, specially, of sulpho-carbonate of potassium. — 

 On a modification of the pneumatic mercury machine, by M. 



Serret. This consists in substituting a simple valve for the glass 

 stopcocks. In another form, even the valve is suppressed, and 

 vacuum obtained by free circulation of mercury in simple tubes. 

 — On solar spots, by M. Tacchini. He thinks the sun's surface 

 at present in a true state of repose relatively to the great pheno- 

 mena observed at a time of maximum sun-spots. He shows the 

 contrast in metallic eruptions and spots between 1S71 and 1876 

 by figures. In the first four months of 1877, he adds, there has 

 been a diminution in the visibility of magnesium, so that the 

 line 1474 K has had a marked superiority. — On the otheoscope, 

 (a new arrangement of the radiometer), by Mr. Crookes. — 

 Direct transformation of mechanical work into electricity, by M. 

 Guignet. In an electromagnetic machine, having six electro- 

 magnets and a drum with six bars of soft iron, the wires are 

 connected with a galvanometer and the drum is rotated by the 

 hand. A continuous current is thus produced, and it is reversed 

 on reversing the rotation. This experiment also shows the in- 

 duction taking place under the influence of the earth ; the soft 

 iron is magnetised, and the magnetisation increases with the 

 speed of rotation. — Note on work in chemistry at the Poly- 

 technical School of Rio de Janeiro, by M. Guignet. ^On work 

 of the School of Mines of Ouro Preto, by M. Gorceix. — On some 

 monochlorised acids of the amylic series, by M. Demar9ay. — On 

 the salts of sesquioxide of chromium, by M. Etard. — Researches 

 on pseudopurpurine ; continuance of researches on the colouring 

 matters of madder, by M. Rosenstiehl. The remarkable insta- 

 bility of pseudopurpurine (he says) is a happy circumstance; as 

 neither it nor alizarine could give a plant the extraordinary 

 importance of madder. — On an application of the microscope to 

 ceramic art, by MM. Fouque and De Cessac. This refers to 

 vases found at .Santorin. — On a new larval form of Cestoides, by 

 M. Villot. — On granular conjunctivitis in Eg)-pt ; rcsiiin! of 

 observations on ophthalmias of North Africa, by M. Gayat. 

 Eye diseases are endemic in North Africti, and have their common 

 origin in granular conjunctivitis, which is brought on by atmo- 

 spheric and terrestrial conditions. — Treatment of hypopyon, by 

 M. Fano. — On Jf. Maumene's gas hydrometer, by M. Dumas. 

 — A new arrangement of the electromagnetic induction apjiaratus 

 with automatic interruption, by M. Becquerel. — On the glaciers 

 of Greenland, by M. Malland. 



Rome 

 R. Accademia dei Lincei, April 15. — The Age of Bronze 

 in the piles of Peschiera in the Lago di Gardo, by M. Ferri. — 

 On the use of the reversed siphon in the ancient conduits of 

 water, by M. Lanciani. 



CONTENTS Page 



Science and War, II. Ey H. Baden Pritchabd 57 



The Forests of Pegu 58 



Influence OF Clihiate ON Pulmonary Consumption 59 



Our Book Shelf : — 



"Annals of the Astronomical Observatory o! Harvard College " . Go 

 Burbidge's *' Cultivated Plants their Propagation and Improve- 

 ment" Co 



Letters to the Editor : — 



The "Hibernation" of Birds— The I^Reviewer of Palmen's 



Work 61 



Barlow's and Laslett's Determination of the El.isticity and St.-'_ngth 



ofTimber.— S. FiGEE . . . 6i 



Basking Shark.— Dr. E. Perceval Wright 6i 



Gold in C.irboniferous Conglomerate. — D. Honevman 62 



Japanese Mirrors.— R. W. Atkinson 62 



The Decennial Period of Magnetic Variations, and of Sun- 

 Spot Frequency. By John Allan Broun, F.R.S 62 



How TO Draw a Straight Line. By A. I). Kempe, B.A. {}V,th 



IllustrcttioHs) 65 



Fossil Floras and Glacial Periods. Ey J. W. Dawson . . . • 67 



A New Stimulant— Pitury f8 



The Antiquity of Man 69 



Our Astronomical Column : — 



The Revolving Double Stars 70 



Physical Observations of Mars 70 



Chemical Notes : — 



Crystallisation under G.Mvanic Currents 71 



Isodibutylene 71 



On the Thermic Formation of Ozone 71 



Chlorophyll in Conifera; 71 



Chemistry of the Grape 71 



Notes 71 



University and Educational Intelligence 74 



Societies and Academies 74 



