Feb. 29, 1872J 



NATURE 



341 



no power whatever to enforce the laws it might make, and 

 could not be expected to put an end to discussion on these 

 points. The linot must be untied, not cut. 



2nd. That the binomial system of nomenclature should not 

 be arbitrarily considered to liave commenced at any given date ; 

 but that recognisable niraes in all works in which this system is 

 methodically employed sliould be used according to the rule of 

 priority. 



3rd. That it is not necessary to suppress a generic name in 

 zoology because it has been previously used in botany (or vice 

 versa); but that it is much to be regretted that any generic name 

 should thus be in double use, and it should always be made 

 matter of reproach to an author that he has committed an act of 

 this nature. 



4th. That names must be Latin to the extent that renders 

 them capable of being written or used in scientific Latin ; but 

 that classical emendations beyond this are entirely inadmissible ; 

 no line except ihi^ can be drawn between emendation, alteration, 

 and total suppression. The laws of classical lanjjuages have, 

 per se, no more right over scientific nomenclature than has the 

 Hindoo language. As regards the much talked-of " Amphio- 

 nycha knownothing, " it should be latinised in the simplest man- 

 ner, as Ainphioiivcha knownot/iiiiga : and I would further suggest 

 that ils barbarian author be well hissed whenever he ventures to 

 show his face in a scientific assembly. 



5th. That as regards placing an author's name after a species, 

 the name so placed should always be that of the first describer 

 of the species ; not because he has any right in the matter, but 

 as an additional means of certainty, and as a security against 

 change. 



6th. That the specific name is the name of an object, and 

 therefore a noun, and should be changed in gender, or any other 

 manner, when removed from one genus to another. 



7th. That it is very undesirable to use the same specific name 

 in two closely-allied genera ; but that where this has been done 

 already no alteration should be made till the two names actually 

 come into collision on account of the two genera being united as 

 one genus. Surely to act otherwise is like cutting one's throat 

 for fear somebody else should do it. 



8ih. That as regards placing an author's name after a genus, 

 the name so placed should be that ot the author who established 

 the genus in the sense in which it is actually used. Caraluis of 

 Linna;us included ail the insects now comprised in tlie family 

 Caraltii/tr, at present divided into several hundreds of genera. 

 To write, therefore, Caraiiis Linn., when we mean something 

 entirely different, may be usual but is not desirable. 



I may add, that I consider it useless to expect a perfectly 

 stable zoological nomenclature, until zoology itself is complete 

 and perfect ; but that in order to reduce changes to a minimum, 

 classical and other secondary claims must not be allowed any 

 great importance. 



D. Sharp 



Thoruhill, Dumfriesshir 



Deep-Sea Soundings 



In reference to the very interesting article in Nature for 

 February 22, "American Deep-Sea Soundings," may I be per- 

 mitted to make the following remarks : — It is there stated that 

 the waler-coUecting cylinder is apt to lead to incorrect con- 

 clusions in regard to the gaseous ingredients of sea water obtained 

 by its means fiom great depths, owing to the escape of a por- 

 tion of the gases when the pressure is reUeved by the cylinder 

 being drawn to the surface. As a member of the l\n-ciipine ex- 

 peditions of 1S69 and 1870, I had nearly eight weeks' constant 

 daily experience m the examination ot samples of abyssal water 

 thus obtained, and I believe that I was the first to adapt the 

 gas analysis apparatus of the late Prof W. A. Miller to the 

 exigencies of a laboratory on board ship. The general result 

 of these experiments for 1869 will be found as an appendix in 

 No. 121 of the Proceedings of the Royal Society. I\Iy object 

 in writing now is to point out that if there were such an escape 

 of gaseous ingredients as is indicated above, the abyssal water 

 would be so saturated with them at the ordinary atmospheric 

 pressure (i.e. after the sample was removed from the water C)lin- 

 der in the laboratorj), that the least elevation of temperature 

 would be sufficient to cause a further quantity to be given off. 

 This, however, never was the case, since I invariably noticed that 

 there was no appearance of bubbles of gas, until the water had 



been heated above 120° Fahr., and frequently still hotter. I may 

 add that the only samples of water which appeared saturated 

 with gaseous ingredients were those taken at the surface, afte 

 several hours of strong wind. I must confess that after giving a 

 good deal of thought to the subject, and conversing with friends 

 whose knowledge of physics is far greater than mine, who agree 

 with my view of the matter, I am unable to see any reason why 

 we should expect to find any greater quantity of gaseous in- 

 gredients in abyssal than in surface water. No doubt, if the ex- 

 cess were there the enormous pressure would retain it, but 

 where is the source of the supply of the supposed excess ? I have 

 never seen a satisfactory answer to this question. The solvent is 

 exposed to excessive pressure, but the gases to be dissolved in it 

 are not, unless there is any evolution of gas at those depths. It 

 is probable that this abyssal water was at some point in its cir- 

 culation near the surfice, when an interchange would take place 

 between some of its dissolved carbonic acid and the oxygen of 

 the almosphere. And it appears to me that it is only when the 

 particles of sea water are near the surface, and exposed to no ex- 

 cess of pressure, that they dissolve their gaseous ingredients, 

 which are afterwards modified in their composition by the animal 

 life on the sea bottom. William Lant Carpenter 



Clifton, Bristol, February 26 



Snow at the Mouth of a Fiery Furnace 



It would be interesting to ascertain the temperature of the 

 saltatory drops noticed by Mr. H. W. Preece. Sudden and ex- 

 cessive evaporation may have produced actual congelation. 



Henry H. Higgins 



ON THE SPECTRUM OF THE A TMOSPHERE 



TOURING the voyage out to India of the Eclipse Ex- 

 -■-^ pedition, I took every opportunity of observing care- 

 fully the spectrum given at sunrise, compared with that at 

 sun-high, and obtained the following results, which, though 

 poor in themselves, will show the wide field open for 

 further research. 



When leaving England, and for some way into the 

 Mediterranean, the length of the spectrum as seen at sun- 

 rise extended generally from about B in the red to near 

 G in the violet. Great differences were, however, presented 

 in the absorption-lines according to the state of the 

 weather, or perhaps rather according to the state of the 

 sky when the sun rose. 



If the sun rose among yellow tinted clouds, the absorp- 

 tion bands about B, C, between C and D, and near D, 

 were exceedingly well defined ; at the same time the blue 

 end did not extend so far as usual, showing that there was 

 more absorption of the blue, while probably the greater 

 quantity of aqueous vapour in the air reflected the red 

 and yellow rays. In these cases the tint of the clouds 

 generally changed to a rosy red shortly after sunrise. 



A clear sunrise, on the contrary, showed an extension 

 of the violet end, whilst the aqueous bands at B, C, and 

 D were less defined, as if the red and yellow light were 

 not so strong to show them out by contrast. 



On passing through the Suez Canal and down the Red 

 Sea the spectrum was shortened at both ends, leaving 

 from little beyond C to a third from F to G ; this would 

 seem to show a general absorption going on in the atmo- 

 sphere from some cause, probably light dust in the air. 

 This idea is strengthened by the beautiful purple colour 

 of the distant mountains, as if, though the violet rays were 

 greatly absorbed, the red rays were so to a less degree, 

 whilst the want of aqueous vapour allowed nearly all the 

 yellow rays to be transmitted. 



When clear of the Red Sea in the Indian Ocean, the 

 blue became greatly reduced, and the red end extended 

 to A ; the aqueous bands were very strong indeed, so 

 much so that on two mornings D^ and Dj could hardly 



