6i8 



NA TURE 



[October 24, 1895 



ijuestion here. For ten years I have been engiiged in 

 (Iredging and trawling about the coasts of Scotland, chiefly 

 as captain of Dr. Murray's )-acht Medusa, and my ex])erience 

 does not coincide with that of Messrs. Brady, Scott, Thompson, 

 and Herdman. Kor instance, in Loch Kyne I have always been 

 able at any time of the year to collect in half an hour enormous 

 numbers of Eiitluita, Calainn. and Xyctiphaius over the mud 

 in depths of about 70 fathf»ms or i;realer. Any person can see 

 at the Millport Biological .Station large bottles filled with these 

 Crustaceans taken in a single haul. The stomachs of the herrings 

 are frequently crammed with these Crustaceans, and the herrings 

 certainly never got this foml about the Laminarian zone, as 

 suggested in Prof. Herdman's address. 



Dr. David Rot)ertson, who is one of the best-known collectors 

 in the country, jwinted out years ago that the Loch Kyne 

 herrings got their food in the deep water, and attributed their 

 fine quality to this fact. Dr. Robertson authorises me to say 

 that, though there may be more species of Copepods in the 

 Laminarian zone than in the deep water, still the number of 

 individuals is very nmch greater in the deep water over the mud, 

 .as is conclusively proved by the Mtdiisa's work. 



Pro|jer methods must, of course, be used, for I know of at 

 least one instance in «hich a gentleman of considerable 

 scientific repute was prepared to say that tlie free-swimming 

 Crustaceans over the mud had completely left Loch Kyne ; he 

 communicated his opinion to Dr. Murray, with the result that 

 the Midina was ordered to Loch Fyne to investigate the matter. 

 -\s was expected, the result was that these Crustaceans were 

 found in as great proftision as on any previous occasion. 



The result of my experience in Loch I'yne is that the nearer 

 the nets are dragged to the mud in the deep water tlie greater 

 will be the number of Eiiilutta, Cahinis, and Nyiliphaius 

 captured. I have taken, hundreds of times, in 70 fathoms, in a 

 single haul lasting from twenty minutes to half an hour, more 

 Copepods than can be collected in the Laminarian zone in eight 

 or ten days. I have also captured herrings by means of drift 

 nets sunk to the Wittom, in depths of 70 and 80 fathoms, and 

 their stomachs were filled with Crustaceans of the same species 

 as we captured by the nets just over the mud at these depths. 



hs, to the deep mud in Loch Fyne not producing a rich fauna, 

 I may state that in the dee|x:st water the trawl could not lie kept 

 down for a longer time than alxiut half an hour ; otherwise the 

 deck engine and all other appliances on board would have failed 

 to bring the net to the surface through sheer weight, chiefly of 

 organisms. There was generally a certain i>erccntage of nuid 

 present, but the lag of the net was generally crammed with 

 thousands of Artini,, , which live there, along with Pictcii 

 sfptemradiattis, Hippolytt , PandaliiF, Cratigon, .-tsfidiairf, and 

 many other invertebrates and fishes. 



I have dredged Loch Fyne systematically for months, and 

 examined its fauna from the littoral zone to the greatest depth : 

 the specimens collected are now licside me, and all the journals 

 with the notes are in Dr. Murray's |iossession. But I think 

 enough has I)een said to show thai the greatest abundance of 

 Copcp<xJs is not to lie found in the Laminarian or other .shallow 

 zones, but in the deep water over the mud ; also that the deep 

 mud doas |kis.sc.ss a very rich fauna. I sjwak only of the 

 abundance of the aliove-menlioned organisms, with which I am 

 well acquainted. I am not a s|)ecialisl nor a scientific man. but 

 I have had a great deal to do with the jiraclical |>art of the 

 investigations which have assisted Dr. Murray in drawing his 

 conclusions. Ai.i:\AMir.R Tiriivni-,. 



.Millport, Cumbrae, N.H. , October 5. 



The Toronto Meeting of the British Association. 



An effort will lie made to have the meeting of the .American 

 Association for the Advancement of Science held at San Fran- 

 cisco in 1897, so that the memliers of the British .'\s.sf>ciation may 

 rross the continent, and join us there, either iK'fore or after their 

 own meeting at Toronto, which many of us ho|)e to attenil. 



A suggestion of great importance, and deserving immediate 

 consideration, seems to me that the Australasian As.sociation 

 should try to arrange a meeting for the .siime year on (he Pacific 

 roast of America, vi thai we may all join in the meeting of the 



^ • ^ iilion at .San Francisco. This will 1m; the first 



"f lliese Associations on that cojusi, and hence a 

 i^ion. 

 know how to reach the officers of the Australasian 

 : but think that an insertion of this letter in Naiurk 



NO. 1356, VOL. 52] 



will find them. I have already sent a letter at a venture to the 

 President by his official title, as I do not know his name, in care 

 of the Post-master of Melbourne, to be forwarded ; but perhaps 

 the Post-master may not know where to send it. 



I have also written to Mayor .Sutro of San Fr,ancisco, calling 

 his attention to it. Wm. H. Halic 



Brooklyn, October 9. 



The Theory of Magnetic Action upon Light. 



I.N the British Association Reports for iSg,. Mr. Lirmor has 

 attempted to show that a satisfactory theory of magnetic action 

 upon light can be constructed by means of a modification of 

 MaxwcUs theory which was proposed by Prof. I'it/4;erald in 

 1879 : and he alleges, with special emphasis (see \i. 349), thai 

 his theory furnishes "a consistent scheme of equations of reflec- 

 tion and refraction, without the necessity of comloning any 

 dynamical ditViculties in the process."' And on p. 359, after 

 raising objections against a theory originally suggested by Prof. 

 Rowland, and afterwards fully developed by myself, he says : — 

 " But against this procedure,'' that is my own. " there stands 

 the |>ure assumption as regards discontinuity of electric force at 

 an interface. ' 



To fully discuss the defects of Larmor's resuscitation of Fitz- 

 gerald's theory would occupy too much space, and would 

 necessitate the introduction of a considerable amount of mathe- 

 matical analysis. I shall, therefore, confine myself to pointing 

 out that his theor)' is open to exactly the same objections as 

 my own, viz. discoiitiiiiiily of the taiii;iiitial component of elcctro- 

 iiiolive foree at an interfaee. 



One of Larmor's boundary conditions (see p. 349) is equivalent 

 to the condition that the expression 



should be continuous. Now 4ir^/K = Q, where Q is one ol 

 the tangential components of the K.M.F. at an interface ; also 

 in immagnetised media C = o. Conscciuenlly, if accenteil 

 letters refer to the latter medium, the condition becomes 



I,) + 4nCd0/de - i6ir°Cy^//dl = Q' ; 



in other words, tic tangential eomponeni of t/u E.M.F. is 

 discontinuous. \. B. Bassist. 



Molyport, Berks, October 9. 



The Society of Chemical Industry and Abstracts. 



.\i the recent annual meeting of the .Society of Chemical 

 Industry, the retiring President and the new President each made 

 some remarks concerning the cost of the journal of the Society, 

 and the necessity of curtailing expenses by dealing more strictly 

 with the abstracts. I suppose hanlly any two of us would (piite 

 agree as to what is the rubbish, Teutonic or otherwise, which 

 ought to be left out, and what is good matter, which ought to be 

 abslmcled at greater or less length. No matter who is editor, 

 all of us would abide as firmly as ever in the belief that we could 

 have made a better selection of articles for abstr.iclion. Before, 

 however, we set about any further movement in the direction of 

 culling down ab.str.acts to a mere useless list of titles, I would 

 like to point out one direction in which expense might .safely be 

 curtailed without fear of objection from any quarter. All will 

 agree, I am sure, that it is a w.a.ste of money to abstract the 

 same article twice. I am sure other memliers besides myself 

 nmst have noticed that this blemish is not entirely absent from 

 the Society's journal. It shoidd be known to every chemical 

 babe and suckling, that even very tmimporlant jjapers arc some- 

 times published more than once. Vet this seems to have 

 escaped the notice of whoever is responsible for the editing 

 of the abstracts. Witness the following front this year's 

 journal: — P. 389, "Sulphides of Colialt and Nickel, .\. 

 Villiers (Hull. Soc. Chini., 1895, '3 UD- •""' " Qualilatij'f 

 SeiKiration of Nickel from Cobalt, A. \illiers, /iull. ,Soc. 

 Cliim., 1895, 13 (4I." Now let us turn to p. 524, where we 

 find, "Sulphides of Nickel and Cobalt, A. X'illiers, Comptes rend., 

 1894, 119. and on p. 509, " (,)ualilative Separation of Nickel 

 and Cobalt, .\. Villiers, Comptes rend., 1895, 120." We 

 have cobalt and nickel in one case, and nickel and cobalt 

 in the other ; but the articles from the Jiutl. Sot. C/iini. 

 are the same as those from the Comptes rend., and by the 

 same author. A still more incomprehensible example will 



