yune 29, 1876] 



NATURE 



197 



Declination . . . 



Dip 



Total Force . . . 



1° S4'72 W. 

 46° 15' 

 10 04850 



The value of the declination is very reliable, as it depends on 

 observations taken every half hour from 6 A. M. to 6 p. M. on four 

 days each month in 1874, and on eight days a month in 1875. 

 The dip results from six complete observations, and the horizontal 

 component of the intensity was determined twice a month in 

 1S74, and every week in 1875. 



Previous dip observations at Shang-Hai, by Sir E. Home in 

 1843, and by Capt. Shadwell in 1858, give - 2''2 and — 3' -4 

 as the secular variation for 1851 and 1862, the latter differing but 

 slightly from the present variation in England. 



Comparing the monthly means of the horizontal force for the 

 winter and summer of 1874-75, we find an excess of o "00074 in 

 favour of the winter, when the sun is nearest the earth. The 

 extreme variation is only 000577, and both maximum and mini- 

 mum occur in the summer months. 



From a limited number of night observations it appears that 

 the range of the declination needle is much more confined, whilst 

 the sun is below the horizon than during the day hours. The 

 diurnal variation is regular throughout the year, but the daily 

 changes in winter are less simple than those of summer. The 

 following are the mean results for the separate seasons : — 

 Mean. Min. at Max. at 



Spring I 50 49 ... 9 A.M. i 47 33 ... 2 p.m. i 54 3 



Summer i 49 39 ... 8 „ i 45 45 ... 2 „ i 53 3 



Autumn i 59 35 ... 9 „ i 58 9 ... i „ 2 I 10 



Wmter i 58 51 ... 9 .. i 57 32 ••• i ..205 



The timo of the principal minimum is more constant than that 

 of the maximum, the latter being anticipated by one hour in 

 winter. 



A sudden change from 1° 50' 13" on Sept. 21 to 1° 56' 51" on 

 Sept. 26, 1874, seems to require further confirmation (which it 

 did not receive in 1875) before it can be considered as more than 

 accidentally connected with the passage of the sun through the 

 autumnal equinox. 



The monthly mean value of the declination is greatest in 

 November and least in June, and the absolute maximum and 

 minimum were : — 



2° 3' 49" at iih. 15m. A.M. on November 8, 

 and 



1° 41' 58" at 9 A.M. on June 29. 

 giving a yearly range of only 21' 51", whilst the secular variation 

 amoun'.s to + 5''85. The value on Nov. 8 was also evidently 

 increased by some irregular disturbance. 



The comparison of the yearly means for the different hours 

 with the hourly means for each season, shows that the sun's posi- 

 tion with regard to the equator has a decided effect on the mag- 

 netic declination, as increase and diminution in summer invariably 

 correspond with diminution and increase in winter. 



In discussing the hourly velocity of the needle, it is found that 

 the acceleration is greatest between 10 and 11 A.M., when the 

 magnet is near its mean position, and that the A. M. max'mum 

 velocity is an hour earlier, and the p.m. maximum an hour la'er 

 in summer than in winter, the greatest velocity being about l"'5 

 p;r minute. 



The mean amplitude of the daily excursions of the declination 

 magnet is 7' '88 in summer against 3' '68 in winter, June giving 

 the maximum mean amplitude of 9' '06, and December the mini- 

 mum of 2'-95. The value of i'*92 in February appears to be 

 exceptional. The greatest extent of a daily oscillation in the 

 course of the twelve months was ii'-o5 on June i, and the least 

 i'*i3 on Feb. 20, giving a maximum yearly variation of 9' '92. 



The changes of the magnetic elements appear to be remarkably 

 small throughout, and very free from irregular disturbances. The 

 cire with which the observations are taken, and the efficient way 

 in which they are discussed, are an earnest of the plentiful harvest 

 we have every reason to expect from this land once so famous, 

 but hitherto so neglected by modern science. 



Stonyhurst Observatory, April 13 S. J. Perry 



THE CHALLENGER EXPEDITION 



VITE have great pleasure in availing ourselves of the per- 



* ' mission to publish the following correspondence 



which has passed through our hands, and in congratulating 



the staff of the Challenger, on having deserved so weighty 



a testimonial of success. It is an additional assurance 

 that their three years' labour has not been in vain, that so 

 many distinguished men of science have been impelled to 

 speak of it in such terms, as well as a guarantee to the 

 British Government that they did a wise thing in equipping 

 the expedition ; we hope it will be an encouragement to 

 the latter to continue to deserve such golden opinions. 

 To the Editor of ''Nature " 



Vienna, Jime 12, 1876 

 Sir, — After having followed the reports of the naturalists of 

 H. M. S. Challenger with the utmost interest, we beg leave to 

 ask you kindly to transmit this simple but sincere expression of 

 a hearty welcome and of thankful admiration to these distin- 

 guished gentlemen, as well as to the officers and the crew of this 

 gallant ship, which has been called to render such prominent 

 services to science. Yours most respectfully, 



Edw. Suess, M. p. Prof. University, 



Vienna, 

 C. Claus, 



G. TSCHERMAK, 



F. Steindachner, Director of the 

 Imper. Zoolog. Museum, 



Dr. Fr. Brauer, Custos of the 

 Imper. Zoolog. Museum, 



E. v. Marenzeller, 

 Prof. Dr. J. Hann, 



F. Karrer, 



Th. Fuchs, Custos am k.k. Hof. 



Min. Cab., 

 P«lzeln, Custos am k.k. Zoolog. 



Cabinete. . 



To this the following reply has been made by Sir C. 

 Thomson : — 



To the Editor of ''Nature'" 

 20, Palmerston Place, Edinburgh, June 23, 1876 

 My dear Sir, — I received your note and enclosure last evening. 

 Will you allow me through you to express on my own part and 

 on that of my colleagues Civilian and Naval on board the Chal- 

 lender, our deep gratification at the kind way in which the 

 leaders of Natural Science in Vienna have expressed their 

 approval of our efforts to extend the limits of knowledge in 

 Physical Geography ? 



We hope that the Empire, which by the most instructive 

 voyage of the Novara immediately preceded us in a similar line 

 of research, may be among the first to aid in filling up the rich 

 details of the new zoological region of which we have been able 

 hitherto to supply only an outline. 



I am, my dear Sir, yours very faithfully, 



C. Wyville Thomson, 



Director of the Civilian Scientific Stafif 



of the Challenger Expedition. 



ABSTRACT REPORT TO "NATURE" ON EX- 

 PERIMENTATION ON ANIMALS FOR THE 

 ADVANCE OF PRACTICAL MEDICINE^ 



III. 



Experimental Researches on Ancesthesia Local and 

 General. 



THE revival of methods for rendering surgical ope- 

 rations on men and animals perfectly painless, 

 while it has been one of the greatest of the advances of 

 modern medical art, has not been without its alloy. The 

 present generation can scarcely appreciate what were the 

 scenes of the operating theatre before the introduction of 

 anaesthesia. The present generation that is not medical 

 cannot appreciate now what is the scene at an operation 

 when the agent employed to prevent pain proves an 

 agent of death. One surgeon I know has been present 

 at six of these fatal catastrophes under and from anaes- 

 thetics. Such an experience shakes the strongest heart. 

 Here is a human being talking cheerfully and resigning 

 himself with full confidence to his medical friends. The 

 operation to be performed may be the act of seconds 



' Continued irom p. 152. 



