2 



SCIENCE. 



We do not propose in this notice to epitomize the 

 report; we prefer to do more justice to the subject by 

 presenting from time to time brief abstracts of the 

 paper, some of which are very elaborate, occupying 

 1 60 pages of closely printed matter, and 90 illustra- 

 tions. 



That part of the report describing the success of the 

 commission in propagating salmon has been anticipa- 

 ted by the public press, but many of the details now 

 given are new and of great interest. Many persons in 

 the East will be astonished at the large scale of the 

 salmon fishery in the Western rivers, where seven to 

 nine thousand fish are sometimes taken in one day. 

 From one station (the St. Cloud river), fourteen mil- 

 lions of eggs of salmon were secured and embryonized 

 — sufficient to keep up the supply being returned to 

 the river, the remainder were sent East; 7,250,000 

 arrived in Chicago between the 3rd and 7th of Oc- 

 tober. The report states that, after supplying the home 

 demand, 500,000 were presented to Canada, 100,000 

 to England, 100,000 to France, 100,000 to Holland, 

 250,000 to Germany and 200,000 to New Zealand. 



In regard to shipments to the last named country, 

 it is satisfactory to be able to state, that they not only 

 arrived in perfect condition, but that by the latest 

 advices the young fish were seen in every direction, 

 promising to be the ancestors of a numerous progeny. 



Reference is made to Professor W. O. Atwater's 

 investigations upon the food qualities of various spec- 

 ies of fishes, the chief facts relating to which we were 

 able to present in an abstracted form, to the readers 

 of " Science," a few weeks since. 



Various attempts have been made to introduce live 

 specimens of the English Sole, one of the most de- 

 licious and prolific of British fishes. The last attempt 

 by Mr. Fred. Mather, whose skill in fish culture is ac- 

 knowledged in the report, was unfortunately like the 

 rest — a failure. Mr. Mather gives a very reasonable 

 explanation of his want of success, and it must be ad- 

 mitted that he was not supplied with the necessary con- 

 veniences. During 1880, Captain Mortimer was 

 more successful, and succeeded in placing living spec- 

 imens of the Sole (Solca vulgaris) in New York harbor. 

 Captain Mortimer explained to us that his apparatus 

 consisted of a tank having a fixed cover, to which were 

 attached two globes, the constant rolling of the ves- 

 sel causing the water of the tank to pass to the globes 

 and return, thus keeping up a constant aeration for 

 the fish, which naturally remained at the bottom. 



We reluctantly close our notice of this most valua- 

 ble and interesting Report feeling that our task has 

 been but half fulfilled. We shall, however, again take 

 up the subject in greater detail, and present our read- j 

 ers with many facts of much scientific interest. 



THE AMERICAN CHEMICAL SOCIETY.* 



The January meeting of the above Society was held in 

 their rooms, Monday evening, January 3, 1881, Prof. C. F. 

 Chandler in the President's chair. The nominations of 

 Messrs. James F. Slade, Theodore M. Hopke, A. F. Hop- 

 pick as regular, and of Mr. E. K. Dunham as associate 

 members were made. The resignations of Prof. Ira Rem- 

 sen, Prof. S. P. Sadtler and Mr. L. W. Drew, read and 

 accepted. A motion for the reduction of the annual dues 

 from $10 to $5 was favorably considered, and the day of 

 meeting was changed from Thursday to Monday, so that 

 in the future, meetings will be held on the first and third 

 Mondays of each month, instead of on the corresponding 

 Thursdays. There being no papers before the society, the 

 meeting was adjourned. We add herewith a list of the 

 officers chosen at the December meeting ior the present 

 year : President, Prof. C. F. Chandler ; Vice-Presidents, 

 A. R. Leeds, G. A. Koenig, E. R. Squibb, Charles A. 

 Goessmann, Henry Morten, Ira Remsen ; Corresponding 

 1 Secretary, P. Casamaior ; Recording Secretary, Albert H. 

 Gallatin ; Treasurer, W. H. Nichols ; Librarian, E. Waller ; 

 Curators, W. Rupp, A. I. Rossi, A. A. Fesquet. 



ON A THERMO-MAGNETIC THERMOSCOPE. 

 By Sir William Thomson. 



This thtrmoscope is founded on the change produced 

 in the magnetic moment of a steel magnet by change of 

 temperature. Several different forms suggest themselves. 

 The one which seems best adapted to give good results 

 is to be made as follows : 



1. Prepare an approximately astatic system of two thin 

 hardened steel wires, r b,r x b\ each one centimetre long, 

 one of them, r b, hung by a single silk fibre, and the other 

 hung bifilarly from it by fibres about three centimetres 

 long, so attached that the projections of the two on a 

 horizontal plane shall be inclined at an angle of about .01 

 of a radian (or .57') to one ano;her. 



2. Hang a very small, light mirror, bifilarly from the 

 lower of the two wires. 



3. Magnetize the two wires to very exactly equal mag- 

 netic moments in the dissimilar directions. This is easily 

 done by a few successive trials, to make them rest as 

 nearly as possible perpendicular to the magnetic me- 

 ridian. 



4. Take two pieces of equal and similar straight steel 

 wire, well hardened, each two centimetres long, and 

 about .04 centimetres diameter. Magnetize them equally 

 and similarly, and mount them on a suitable frame to 

 fulfil conditions. 



5 and 6. Call them R B and R 1 B 1 , B and B 1 denoting 

 the ends containing true north polarity (ordinarily marked 

 B), and R R 1 true south (ordinarily marked red). The 

 small letters, r, b, r l , 3\ mark on the same plan the polar- 

 ites of r b and r ] b'. 



3. The magnets R B, R 1 B', are to be relatively fixed in 

 line on their frame with similar poles next one another, at 

 a distance of about two centimetres asunder, as thus, 

 R B . . . B 1 R 1 , with BB' = two centimetres. 



6. This frame is to be mounted on a geometrical slide 

 upon the case, within which the astatic pair, r b, r 1 b\ is 

 hung in such a manner that the line of R B, B R bisects 

 rb, approximately at right angles, and that R BB R may 

 be moved by a micrometer screw through about a milli- 

 metre on each side of its central position, the line of 

 motion being the line of R B, B 1 R 1 , and the " central 

 position" being that in which B and B 1 are equi-distant 

 from the centre of r b. 



7. A lamp and scale, With proper focjssing lens if the 

 mirror is not concave, are applied to show and measure 

 small deflections as in my mirror galvanometres and elec- 

 trometer. 



* Communicated by M. Benjamin, Ph. B. 



