DtCEMliER 16. 1^97] 



NA TURE 



159 



the preparation of marine animals and plants as transparent 

 lantern slides, by Prof. H. C. Sorby, F.R.S. ; and the shape and 

 position of the pancreas and the adjoining viscera, by Prof. C. 

 Addison. The editing committee state that the volume " is pre- 

 sented as an earnest that the new College may in the future be 

 distinguished, not only for the number of students it has trained, 

 but also as a place for the advancement of knowledge." We 

 accept the token, and from its character we are sure that the 

 University College of Sheffield will not be behind in valuable 

 contributions to science. 



The number of cuprous salts at present known is very small 

 in comparison with the large number cf stable cupric salts 

 that can exist. The isolation of cuprous sulphate, in particular, 

 has not yet been effected. In the current number of the Comptes 

 rendiis of the Paris Academy of Sciences there is an interesting 

 account, by M. A. Joannis, of some attempts to isolate this salt, 

 which, although unsuccessful, tend to prove that cuprous sulphate 

 can be formed under certain conditions. Finely divided metallic 

 copper digested with a solution of cupric sulphate, as is well 

 known, undergoes no change. If, however, carbon monoxide 

 is led in, a slow absorption takes place, the copper dissolving, 

 and the solution becoming decolorised. These facts can be 

 accounted for by assuming that cuprous sulphate is formed 

 which combines with the carbon monoxide to form a compound 

 analogous to that obtained from cuprous chloride. The decom- 

 position of this solution when the gas is removed by the mercury 

 pump is somewhat remarkable, for as soon as the pressure is 

 reduced to about 2 mm. a pellicle of metallic copper forms 

 on the surface, and the solution becomes blue, the reaction 

 between cupric sulphate, copper, and carbonic oxide being in 

 fact a reversible one and a function of the pressure of the gas. 



From the December Journal of the Chemical Society, we 

 derive the following particulars of a paper on the production of 

 sugars in beetroot, by Friedrich Strohmer : — The opinion 

 expressed thirty years ago by H. Schacht, that the quality of 

 beetroots depends on the number of developed leaves and the 

 length of life of the plant, is now shown to be free from objec- 

 tions. Sugar is produced in the leaves, either directly as reducing 

 sugar, or from starch or other carbohydrate, and migrates 

 through the leaf stems to the root. The production of sugar 

 depends on the amount of light, and the form and position of 

 the leaves are of importance. When the sunlight passed through 

 white or yellow glass, leaf production was vigorous, but with 

 blue or red glass feeble ; and the weight of roots under the 

 influence of yellow light was nearly twice as great as when blue 

 and red light were employed. The percentage of sugar under 

 the different conditions was 7 •4-8" I with yellow, 6 '4-7 "4 with 

 red, and 8 ■0-8*4 with blue light. For producing total organic 

 substance in beetroot, rays of medium wave-length are the most 

 favourable, but for converting the products of assimilation into 

 sugar, the so-called chemical rays seem to have a prominent rdle. 

 The results of field experiments showed that sugar production 

 begins at an early stage in the leaves, but is greatest from the 

 beginning of August to the middle of September. Under 

 favourable conditions, there may be a not inconsiderable 

 accumulation of sugar even later. From the beginning of July, 

 the sum of the percentages of water and sugar in the roots is 

 constant. This, and the fact that the percentage of sugar in the 

 roots increases until the leaves die, indicates that the sugar, 

 once stored in the roots, remains there. It is only when the 1 

 roots are taken out of the soil and the leaves cut off", that the i 

 sugar begins to be used up in maintaining the life of the plant I 

 and in preparation for second year's growth. j 



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

 past weekj include an Ocelet {Felis pardalis) from Para, pre- 

 NO. 1468, VOL. 57] 



sented by Mr. William Wethered ; an Arctic Fox {Canis lago- 

 pus) from the Arctic Regions, presented by Mr. H. E. Wood ; 

 a Dominican's Cat {Felis dominicanorum), two White-legged 

 Falconets {Microhierax melanoleitcus), a White-browed Laugh- 

 ing Thrush {Dryonastes sannoi), a Collared Jay Thrush (G^a r- 

 rulax picticollis) from the province of Foochoo, China, presented 

 by Messrs. C. B. Rickett and J. De la Touche ; four Burrowing 

 OviXs {Speotyto . cunicularia) from Argentina, presented by Miss 

 Sandys Lumsdaine ; a Common Chameleon {Chamceleon vul- 

 garis) from North Africa, presented by Miss M. L. Peake ; a 

 Golden Eagle {Aqtiila chrysatiis) from Newfoundland, two 

 Black-necked Swans {Cygnus tiigricollis, <J ? ) from Antarctic 

 America, purchased ; a Crested Porcupine {Hystrix cristata), 

 born in the Gardens. 



OUR ASTRONOMICAL COLUMN. 



Oppositions of Two Minor Planets. — The minor planet 

 Ceres will be in opposition to the sun on the 25th of this 

 month. (For elements and coordinates see pages 2 and 3 of 

 Appendix to Nautical Almanac 1897.) Although Ceres is the 

 largest of the asteroids, it is interesting as having to give pre- 

 cedence to Vesta for brightness ; the stellar magnitude at 

 this opposition will be 7'i. Ceres is now describing a retro- 

 grade path on the borders of Auriga and Gemini, near e 

 Geminorum, and has therefore a considerable altitude. 



There is also an opposition, on the 26th inst., of one of the 

 fainter and less well-known minor planets, viz. Gerda, the 

 elements and coordinates for which, as given by M. A. Iwanow, 

 of Pulkova, will be found in Asir. Nach., 3458. At the time of 

 opposition the asteroid will be near to v Geminorum. 



The Total Solar Eclipse of 1900 — Prevision is always 

 a desirable attribute, and to an astronomer it is essential. We 

 are reminded of this by an account given by Prof. Frank H. 

 Bigelow, in the Monthly Weather Review, of the probable 

 meteorological conditions along the path of the total eclipse of 

 the sun, in the United States, on May 28, 1900. Beginning 

 with May 15, of this year, and continuing until June 15, so as 

 to include May 28 centrally, meteorological observations were 

 made at sixty-six stations distributed uniformly over the portions 

 of the States of Virginia, North Carolina, South Carolina, 

 Georgia, Alabama, Mississippi, and Louisiana, crossed by the 

 eclipse track. Observations were made of the general state of 

 the sky at 8 a.m., 8.30 a.m. and 9 a.m., and also of the state 

 of the sky near the sun. The results show that the conditions 

 in the interior of Georgia and Alabama were better than in 

 North Carolina, South Carolina, or Louisiana. Apparently it 

 would be safer to establish eclipse stations in central Georgia or 

 Alabama, upon the southern end of the Appalachian mountains, 

 where the track crosses the elevated areas, than nearer the 

 coastline in either direction, north-eastward towards the Atlantic 

 coast or south-westward towards the Gulf coast. 



It is intended to repeat the observations during the years 

 1898 and 1899, so as to obtain as good information as possible 

 with regard to suitable eclipse stations for the year 1900. 



Corrected Position of the Moon. — It will be re- 

 membered that the Pleiades have been quite recently occulted 

 twice by the moon, once in July and again in October. These 

 occultations were specially observed at Lyons, and in No. 22 

 Co/nptes rendtis, vol. cxxv., M. Lagrula shows that in a series 

 of occultations of stars by the moon, observed at epochs 

 sufficiently near together, it can be supposed that the correc- 

 tions to apply to the tables of our satellite vary proportionally 

 with the times. It is then possible from these to combine the 

 equations of condition supplied by the different phenomena 

 observed. Thus we can obtain with great precision the semi- 

 diameter and the coordinates of the moon at the mean epoch, 

 and even in certain cases her parallax. The two important 

 occultations discussed are those which took place on July 23 

 and October 13, 1897. The results are given in the following 

 table, where D and it represents the semi-diameter and the 

 parallax of the moon at her mean distance ; Ax and a5 the 

 corrections in R.A. and declination, which ought to be applied 



