50 



ASTRONOMY, PROGRESS OF, IN 1891. 



nounced that, in accordance with the custom of 

 his predecessors, who chose as the subject of 

 their addresses a discussion of that branch of 

 science with which they were most familiar, so 

 he would attempt to discuss the progress of 

 agriculture as affected by recent discoveries in 

 chemistry and physiology. At the close of the 

 last century the crudeness of the methods of 

 chemical analysis were such that it was impossi- 

 ble to arrive at a positive knowledge of the com- 

 position of plants. It was De Saussure who, in 

 1804, wrote : " I have found phosphate of lime in, 

 the ashes of all the plants that I have examined, 

 and hence assume it to be a constant constituent 

 of all vegetable life." This naturally led to the 

 artificial application of chemicals to the soil to 

 replace those taken up by the plant. The first 

 of these appears to have been bone ash, and it 

 was not until 1843 that the Duke of Bedford 

 demonstrated the real cause of its efficiency. 

 Liebig's experiments, tending to show that by 

 treating bones with sulphuric acid they became 

 changed into superphosphates, was a distinct ad- 

 vance in the knowledge of the subject. The 

 discoveries of phosphate rock and the great work 

 in England at Rothamsted brings us down to 

 modern times. Thus, by analyzing the ash of 

 plants, chemistry has shown what ingredients 

 are necessary to restore the soil to its normal 

 composition. The condition of nitrogen in the 

 soil and its influence upon vegetation was next 

 taken up. The able researches of George Ville, 

 in France, followed by those in England of 

 Lawes and Gilbert, were referred to, and final- 

 ly the more recent work by Berthelot was men- 

 tioned. In other ways chemistry had rendered 

 great service to agriculture. The terrible dis- 

 ease that threatened to exterminate the vines of 

 France was discussed, and how one means after 

 another was suggested by chemists, until carbon 

 disulphide, proposed by Thenard, and the sulpho- 

 carbonates recommended by Dumas proved effi- 

 cacious. He closed with a brilliant description 

 of the agricultural resources of France, and es- 

 pecially those of the section of France of which 

 Marseilles was the chief city. 



Treasurer's Report. The total receipts dur- 

 ing the year, as reported by Emile Galante, were 

 $19,611, and the total expenditures were $18,325, 

 of which sum $2,160 were grants made to vari- 

 ous scientists engaged in original researches. By 

 various amounts the capital of the association had 

 been increased, until it had now reached the sum 

 of f 170,430. He also announced that the coun- 

 cil were studying means by which this twentieth 

 meeting might be made memorable by reducing 

 the annual dues required of members. In 1872 

 the capital of the association amounted to only 

 $20,000, but now, thanks to the skillful care of 

 its officers, it had reached the sum of $170,000, 

 and in the mean while the sum of $45,000 had 

 been distributed. 



Excursions and Entertainments. Two 

 evening lectures were given, one on Sept. 18 

 and the other on Sept. 21. A reception was held 

 at the Hotel d-e Ville on the evening of Sept. 17. 

 The afternoons were largely devoted to visiting 

 scientific and industrial works. Excursions were 

 made to Aries and to Aix during the meeting, 

 and at its close two days were spent in an exten- 

 .sive trip along, the Mediterranean coast. 



ASTRONOMY, PROGRESS OF, IN 1891. 



Although considerable advance has been made 

 since the close of the preceding report, it can not 

 be claimed that the present year has been char- 

 acterized by important discoveries, such as re- 

 warded the labors of astronomers during 1890. 



The Sun. This year ushers in the beginning 

 of another sun-spot maximum period, which ap- 

 pears to be too early, reckoning from the date of 

 its last occurrence, which was nearly three years 

 too late, to accord with the received interim of 

 about eleven years from maximum to maximum. 

 Thus far during 1891 there has been hardly a 

 day on which spots and extensive fields of faculae 

 have not been observed. 



On June 17, at 10 h 16 m , Paris mean time, M. 

 Trouvelot, an assistant at the Meudon Observa- 

 tory, near Paris, saw a luminous outburst on the 

 sun of apparently the same character, he says, as 

 that seen by Carrington and Hodgson on Sept. 

 1, 1859. The spot was of a yellowish color and 

 near the western limb of the sun. Soon afterward 

 another manifested itself a little to the north, 

 from both of which what appeared to be volcanic 

 bombs were projected. The same phenomena 

 were observed the next day, though with less ac- 

 tivity, and ceased to be noticeable soon after 

 noon. These seem not to have been noticed else- 

 where. 



In No. 85 of the Johns Hopkins University 

 Circular, Prof. Henry A. Rowland enumerates 

 the following elements as certainly existing in 

 the sun by comparison with the solar spectrum 

 from the extreme violet down to D: Calcium, 

 iron, hydrogen, sodium, nickel, magnesium, co- 

 balt, silicon, aluminum, titanium, chromium, 

 manganese, strontium, vanadium, barium, car- 

 bon, scandium, yttrium, zirconium, molybdenum, 

 lanthanum, niobium, palladium, neodymium, cop- 

 per, zinc, cadmium, cerium, glucinium, germani- 

 um, rhodium, silver, tin, lead, erbium, potassium. 



The doubtful elements are : Iridium, osmium, 

 platimim, ruthenium, tantalum, thorium, tung- 

 sten, and uranium. 



Those not found in the solar spectrum are : 

 Antimony, arsenic, bismuth, boron, nitrogen, 

 caesium, gold, iridium, mercury, phosphorus, ru- 

 bidium, selenium, sulphur, thallium, and praeso- 

 dymium. Strangely enough, oxygen, which con- 

 stitutes one half the earth, is not found in any 

 one of the three lists. 



Transit of Mercury. The transit of Mer- 

 cury, May 9, 1891, occurred, on this continent, 

 save for the observatories on the Pacific coast, 

 when the sun was too low to be well observed. 

 Even in that locality the sun had set before the 

 third and fourth contacts took place. At the Lick 

 Observatory, Prof. E. E. Barnard observed the 

 first two contacts as follow : Mt. Hamilton mean 

 time, first contact, 3 h 46 m 32'7 8 . Second contact, 

 3 h 51 m 19-9 9 . Though carefully looked for, no 

 trace of the planet could be detected before first 

 contact, nor was that portion of the planet out- 

 side of the sun's disk between the two contacts 

 visible. The luminous ring encircling the planet, 

 which some observers claim to have seen both 

 during this and the preceding transit, was not 

 seen. This aureola, as it is called, was, at the 

 last transit, clearly observed at at least two sta- 

 tions in India, while at another point in that 

 country it was not visible even to eager search- 



