SCIENCE. 



7 ' 



equatorial and the sun to throw cut the parts of the spec- 

 trum not under examination, and a concave cylindrical 

 lens was used next the eye to reduce the apparent width 

 of the spectrum, and thus increase its brightness. 



From Professor Young's observations it thus appears 

 that the coincidences are only near approximations, but a 

 careful investigation by bringing together the bright-line 

 spectra of the metals and the solar spectrum must be made 

 in order to settle the question conclusively. 



Mr. E. J. Stone has presented to the Royal Astronomi- 

 cal Society the complete sheets of his great Catalogue of 

 Southern Stars, observed during his superintendence of the 

 Royal Observatory, Cape of Good Hope. This very im- 

 portant work contains the places of between twelve and 

 thirteen thousand stars, including, in addition to the stars 

 observed by Lacaille, a considerable number of stars fall- 

 ing within similar limits of magnitude. " A stereographic 

 projection showing the distribution of the stars contained 

 in the Cape Catalogue, 1880, between no° and 180° N. P. 

 D.," has been lithographed by Mr. Stone. — Nature. 



w. c. w. 



As noted in the i c sue of last week, the volume of re- 

 ports on the total eclipse of 1878, has been recently is- 

 sued from the Naval Observatory at Washington. A few 

 separate copies of the report of Mr. D. P. Todd, assist- 

 ant in the office of the American Ephemeris and Nauii- 

 tical Almanac, have been reprinted, mainly for distribu- 

 tion among the gentlemen who co-operated in observing 

 the duration of totality along the limits of total eclipse. 

 Besides the usual observations of contacts, Mr. Todd had 

 planned a search for supposed intra-mercurial planets, 

 having provided himself with the four-inch comet seeker 

 belonging to the Naval Observatory. At his station, how- 

 ever (Dallas, Texas), clouds intervened to such' an extent 

 that 6 Cancri, a fourth magnitude star near the sun, could 

 not be seen. This station was almost the only oue of any 

 importance at which clouds interfered on the day of the 

 eclipse. Mr. Todd describes in his report a new method 

 of procedure in the observation of total eclipses, whereby 

 it would seem that the question of the existence of intra- 

 mercurial planets might be speedily settled. An ar- 

 rangement was concluded between Professor Newcon b 

 (observing in Wyoming), and himself, whereby, if the 

 former should observe any such object, its approximate 

 position shouldjbe telegraphed immediately to the south- 

 ern station for verification — there being about twenty 

 minutes of absolute time intervening the arrival of 

 of the moon's shadow at Wyoming and its 

 reaching Texas. As Professor Newcomb observed no 

 unknown object, there was, of course, no occasion for 

 carrying out this scheme ; but it will readily appear that, 

 had the weather been clear at the southern station, and 

 had the position of the objects seen by Professor Watson, 

 been telegraphed for veriticaticn, the question of small 

 planets near the sun might have been in a much less un- 

 certain condition than it now is. It is to be hoped that 

 astronomers may utilize this scheme on the occasion of 

 the next total eclipse on the 16th of May, of next year. 

 Eleven sketches and one lithograph plate of the corona 

 accompany this report, but they do not exhibit any details 

 of structure worthy of note. But by far the most i:npor- 

 tantant portion of Mr. Todd's report rela'es to the obser- 

 vations of duration of totality, which were made at his 

 solicitation at numerous points along the northeast and 

 southwest limits of total phase. This series of observa- 

 tions will afford a very accurate correction of the longitud 

 of the node of the lunar orbit, whenever the geographical 

 positions of the several stations have been determined 

 i: h sufficient accuracy to be used in the computation. 



NOTE ON SUN SFOTS IN JANUARY, 1881. 

 To the Editor of " SCIENCE :" 



1st, at noon : 5 groups, 11 spots. One spot quite large 

 and close to east edge. Air very tremulous, making 

 observation bad. 



7th, 3 P. M. : 1 group, 3 sjols. Two are large ; nearly 

 north of ctntre. Air bad. Observation with spy- 

 glass, power 36. 



8th, 1 P. M. : 1 group, 4 spots. Air very bad. 

 ioth, Noon : 1 group, 6 spots. Air very bad. Power 

 50. 



nth, P. M. : 2 groups, 9 spots. One group cf 7 

 spo:s 3' from west edge. Two little spots and 

 faculae at east edge. Arr pretty good. 



17th, Noon : 1 group, 2 spo:s. A large spot near half- 

 v\ay from centre to N. W. margin. Observation 

 with spyglass, power 36. 



24th, io>2 A. M. : 3 groups, 23 spots. 12 spots, 2 quite 

 large, south of centre. Air poor. 



1 8 1 h , Nocr ; 5 groups, 66 spcts. One quite large and 5 

 good size, near west edge. Only good observation 

 this month. The sun was hid most of the time. 



Telescope 4.6 inches aperture ; Power 100, except other- 

 wise r oted. 



The number of solar spots has been slowly increasing 

 since Ma - ch, 1879. But it looks likely that the next 

 maximum will be considerably mere than eleven years 

 from the last one, which occurred about August, 1870. 

 The following minimum was nearly nine years afterward. 

 It is generally about seven years lrom maximum to min- 

 imum, then tour years to the next maximum. So I thir k 

 it probable that the period, this time, will be about 

 thirteen jears, making the next maximum in 1883. 



Wm. Dawson. 



Spiceland, Ind., February 2, 1881. 



CHEMICAL NOTES. 



Formation of Bases from Substituted Acid Amides. 

 — O. Wallach and Iwan Kamenski conclude, from their 

 experiments, that if a base is formed by the action of phos- 

 phorous penta-cliloride from a substituted amide of mono- 

 basic acids with a short carbon chain, two molecules of the 

 amide enter into reaction in such a manner that hydrogen is 

 derived from the hydrocaibon radicle pertaining to the acid 

 in order to form hyjrochloric acid. 



Zinc Chloride as a Reagent for Alkaloids, Glyco- 

 sides, Etc. — A. Jorissen has found that the following bo- 

 dies Droduce characteristic reactions with pure zinc chlor- 

 ide: Strychnine, bright rose; thebaine, yellow narceine, 

 olive-green, delphinine, brownish red, berberine, yellow ; 

 veratrine, red ; quinine, pale green ; digitaline, chesnut- 

 brown, salicine, violet-red ; santonine, violet-blue ; cube- 

 bine, carmine red. In case of strychnine the reaction can 

 be produced with I decimilligrm. of the hydrochlorate. 

 Brucine and aconitine, if present, interfere. To obtain the 

 blue coloration characteristic of santonine, the mixture 

 during evaporation must be continually stirred with a glass 

 rod drawn out to a point. Digitaline gives first a green 

 solution, similar to that produced by heating with hydro- 

 chloric acid. After evaporation there remains upon the 

 porcelain a chestnut-brown spot which quickly blackens. 

 The salicine reaction can be used for detecting the fraudu- 

 lent addition of this body to quinine sulphate. Albume- 

 noid substances, if heated for a time with the zinc chloride 

 solution, leave a violet stain upon the porcelain, which 

 may be distinguished by its instability from the colorations 

 mentioned above. As a rule it quickly blackens. The 

 author's method of operating is as follows : A solution of 

 the alkaloid or its hydrochlorate is evaporated to dryness 

 upon the water-bath, say in the inside of the lid of a porce- 

 lain crucible ; two or three drops of the test-solution — 1 

 grm. fused zinc chloride in 30 c.c. concentrated hydro- 

 chloric acid and 30 c.c. water — are placed upon the residue, 

 and dried up afresh on the water-bath. The coloration 

 begins at the outer edge and spreads inwards as the water 

 is expelled. 



