July 23, 1891] 



NATURE 



283 



gelher for several hours upon a water-bath benzaldehyde and 

 hypophosphorous acid in an atmosphere of carbon dioxide. 

 Crystals of the new compound soon commence to separate, and 

 rapidly permeate the whole liquid. On draining and washing, 

 they are found to consist of colourless radiating groups of 

 lamelJK. They are not very soluble in water, but dissolve more 

 readily in organic solvents, best in methyl alcohol. The aqueous 

 solution is strongly acid, decomposing carbonates readily, and 

 forming crystalline salts with bases. Curiously, though, itexerts no 

 reducing action upon solutions of copper sulphate or silver salts. 



CgHj— CH— OH 

 I 

 In order to obtain the acid of the first type, PO — OH, 



H 



it is best to employ an excess of hypophosphorous acid. In this 

 case, instead of crystals of the acid of the second type separating, 

 the whole form? a homogeneous liquid which remains unpre- 

 cipitatel by water. It contains the acid of the first type, and 

 this latter is best isolated by precipitating the lead salt by ihe 

 addition of lead acetate and decomposing the salt, suspended in 

 water, by means of sulphuretted hydrogen. On concentration 

 of the filtered solution, a syrup is obtained which eventually 

 yields deliquescent crystals of the pure acid. The solution of 

 this acid does not reduce copper sulphate, but readily precipitates 

 metallic silver from silver nitrate. Many similar compounds 

 with other aldehydes have also been prepared, and found to 

 present analogous properties more or less modified by the specific 

 nature of the particular aldehyde employed. 



The additions to the Zoological Society's Gardens during the 

 past week include two Ruddy-headed Geese {Bernicla rubidi' 

 ceps i S ) from the Falkland Islands, presented by Mr. F. E- 

 Blaauw, C.M.Z.S. ; a Smooth Snake {Coronella Icsvis), British, 

 presented by Mr. \V. H. B. Pain ; two great Eagle Owls (Bubo 

 maximus), European, deposited ; six Eyed Lizards {Lacerta 

 ccellata), two Four-lined Snakes {Coluber quadrilineatus), a 

 Back-marked Snake {Rhinechis scalaris), South European, 

 purchased ; a Burrhel Wild Sheep {Ovis btirrhel <J ), a Japanese 

 Deer (Cervus sika 9 ), a Bennett's Wallaby {Halmaturus 

 bennetti ? ), two Night Herons {Nycticorax griseus), bred in 

 the Gardens. 



OUR ASTRONOMICAL COLUMN. 



A Cause qf Lunar Libration. — A paper by Mr. S. E. 

 Peal, " On a Possible Cause for Lunar Libration other than an 

 Ellipsoidal Figure, and on Lunar Snow Mountains," has recently 

 been published by Messrs. Dulau and Co. It is shown that 

 evidence of several kinds jioints to the existence of a vast shoal, 

 or submerged continent, some 1500 miles long by 400 across 

 along the prime meridian. This is presumed to be of greater 

 specific gravity than the refrigerated maria east and west of it, 

 and to have been at one time situated in the southern hemi- 

 sphere. The difference of attraction upon the shoal and the 

 surrounding maria is shown to be sufficient both to cause and 

 maintain libration. Since libration began, the shoal has placed 

 itself geocentrically, in which case the south pole must have been 

 drawn forward about 30". The possibilities of the case seem to 

 be as follows. The moon formerly had a physical constitution 

 the same as that of the earth at the present time. The lunar 

 ocean beds were then steadily subsiding, the lines of upheaval 

 and weakness being on the continents, and causing a series of 

 quasi-vQ^czmc orifices. Whilst tidal friction was reducing the 

 velocity of rotation, polar snow-caps were formed, and the 

 atmosphere became rarer. The extension of the snow-cap to 

 the equator was for ages prevented by the incidence of solar 

 heat. This struggle between steadily-increasing refrigeration 

 and solar heat should therefore be evidenced by the existence of 

 an irregular belt about the (then) equator. Such a belt is found 

 in the circular maria Smythii, Crisium, Serenitatis Imbrium, 

 and part of Oceanus Procellarum. If the axis of rotation be 



NO. II 34, VOL. 44] 



shifted about 30°, so that the south pole occurs near Nach or 

 Maginus, all these irregular ?naria form a chain of seas along 

 the equator, which may represent the belt of solar influence 

 referred to. Eventually these maria were refrigerated, and the 

 meridional shoal, acting as a fixed tide during libration, caused 

 the change in the direction of the axis of rotation, which shifted 

 the belt of seas from their equatorial position to that at present 

 occupied by them. 



Double-star Observations.— In Astronomische Nach- 

 richten, Nos. 3047 and 3048, Mr. S. W. Burnham gives the 

 results of his duulile-star observations made in 1890 with the 

 36-inch equatorial of the Lick Observatory. The stars which 

 have been re-observed aie mainly those which cannot easily be 

 measured on account of their being beyond the reach of any 

 but ihe most powerful telescopes. Mr. Burnham also notes that 

 his purpose has not been to find as many pairs as possible with- 

 out reference to their character, but to make several measure- 

 ments of interesting ones. The present catalogue of new stars 

 contains 70 pairs, of which 39 have distances less than i", with 

 an averaije distance of o"'4S. 



The following naked-eye stars are included in the list of new 

 binaries :— B. A.C. 230, 48 Cephei (H), 5 Camelopa'dns, 

 T Herculis, Ceti 199, 34 Persei, v Geaiinorum, 24 Aquarii, 

 95 Piscium, B.A.C. U42, 36 Geminorum, ^^ Aquarii, x Persei, 

 Tauri 148, 65 Geminorum ; and the following pairs, previously 

 known, have been found to be more clo ely double : — H 1981, 

 S 409, 2 809, 02 (app.) 77, 2 2476, 02 425, 2 12 (app. II.). 



Observations of the Zodiacal Counter-glow. — An 

 account of observations of the zodiacal counterglow, or Gegeit- 

 scheitt, made at Mount Hamilton from 1888 to 1891, is con- 

 tributed to the Astronomical Journal, No. 243, by Mr. E. E. 

 Barnard. The changes of form previously noted have been 

 confirmed. In the fall of the jear the Gcgenschein appears 

 large and roundish. It afterwards becomes elongated, and con- 

 nected with the zodiacal light by a narrow zodiacal band. The 

 observations prove that the Gegenschein does not lie in the 

 ecliptic, although very nearly so. Neither is it exactly 180° 

 from the sun. The mean of sixteen observations assign the 

 following longitude and latitude to the phenomenon : — 

 © - A = i8o°-6 ; 3 = -t- i°'3. 



The Observatory of Yale University. — The Report for 

 the year 1890-91 of the Observatory of Yale University conta.ins 

 a report from Dr. Elkin, from which we make the following 

 extracts : — 



" In observational work with the heliometer I have been 

 engaged almost wholly in the continuation of the series on the 

 parallaxes of the first magnitude stars in the northern hemi- 

 sphere. The scheme origmally laid out has now been com- 

 pleted, and furnishes for each of the ten stars three (for Arcturus 

 five) independent results. 



"The triangulation of the comparison stars for Victoria accord- 

 ing to the plan drawn up by Dr. Gill has been carried out by 

 Mr. F. L. Chase, who secured some 450 measures of these stars 

 during the months of June to October 1890. Mr. Chase has 

 also reduced the observations as far as it was advisable for us to 

 do so here, and the results have been communicated to Dr. Gill, 

 along with the reduced results of our observations of Victoria 

 and Sappho in 1889. Since February 1891, Mr. Chase has 

 been engaged in a triangulation of the principal stars in Coma 

 Berenices, and up to date about one-half of the proposed 

 measures have been obtained. 



" It is proposed during the ensuing season to devote the helio- 

 meter to a series of measures on the satellites of Jupiter for t^e 

 deteriiiination of their orbits and the mass of the planet, com- 

 paring them inter se, as has been done with such success by 

 Hermann Struve at Pulkova with those of Saturn." 



THE RECENT EPIDEMIC OF INFLUENZA. 

 'T^HE mortality in London from influenza shows a steady 

 -*■ decline week by week ; and, although the number of 

 deaths is still in excess of the average, there are good rea- 

 sons for hoping that the epidemic will shortly disappear from 

 our midst. The severity of the recent visitation, as compared 

 with that which prevailed last year, is clearly shown by the 

 accompanying diagram, in which the effects of the two epidemics 

 are displayed side by side. The weekly mortality from influenza 

 alone is represented by the thick curve, the number of deaths 



