3H 



NATURE 



{Feb. 19, 1874 



Berlin Time. 



T = Oct. I '80022 



SCIENTIFIC SERIALS 

 In the Journal of Bolany for January, there is no paper of 

 special general interest, the illustration being that of a new 

 British moss Torttila iitclinata. Mr. J. G. Baker describes a 

 number of new or little known capsular gamophyllous Liliacete ; 

 and Mr. F. E. Kitchener gives an "elementary proof of the 

 rule for detecting spiral airangement." The first article in the 

 February No. is an illustration of how much yet remains to be 

 done in completing the Briiish flora, being a description with a 

 plate of a British Docli, Ruiiic.x maximiis, discovered by the 

 Hon. J. L. Warren in the neighbourhood of Lewes, where it 

 was recorded many years since, but not liaving been observed in 

 the meantime, had been generally treated as an error. There is 

 no other paper bearing specially on British Botany, but a very 

 useful account of the Esparto-grass of commerce, byJMr. J. R. 

 Jackson. 



Aslronomische Nachrichtcn, No. 1972. The elements of 

 Henry's comet, 1873, by E. Weiss and Aug. Zielinsky, the 

 following elements are given : — 



Zielinslcy, 

 Paris Time. 

 Oct. 1765792 

 H = 50° -8' 1 8 -"5 50° 1 8' 42" -96 



a = 176° 43' 14" 176° 43' 2 1 ■'•88 



/ = 121° 28' 58 "8 121° 27' 48" -19 



log :j = 9'5S5297 9-5866441 



A list of fifteen new nebulce is given, which M. Stephan ob- 

 served at Marseilles. 



roggeiidorff' s AnnaUu da- Physik uiid Ckcmic, No. 10, 1873. 

 We may first notice, in this number, some observations relat- 

 ing to phenomena of light. — M. Behrens contributes a paper on 

 the production of coloured light through elective relleclion. The 

 reflected and transmitted light of opal and other bodies was ex- 

 amined with a micro-spectroscope ; and it is shown that certain 

 substances may have colour without absorbing light, ond that 

 the two spectra (from i-eflection and transmission, respectively) 

 are exactly complementary of each other. This, he says, occurs 

 more frequently than one might suppose. — Dr. Noggerrath draws 

 attention to the production of Ight in grinding of hard slones, as 

 witnessed in the aiate-woiks at t)berstein and Idar. In the case 

 of all hard stones (which the workmen press with their hands 

 against large grindstones revolving thrice in a seccnd), a strong 

 red light appears between the object and the grindstone, with a 

 red halo and emission of sparks. Transparent stones, however, 

 are lit up throughout with a beautiful yellowish-red light, like 

 that of glowing iron, so that it seems as if the workman must 

 burn his hands (though the rise of temperature was not above 

 10° or 12° R.). The author invites research in this direction, for 

 which ihe works named present good opportunity. — The con- 

 cluding portiiin of M. von Bezola's paper on the law of colour 

 mixture and the physiological primary colours, is given ; the 

 author is led to some valuable deductions which w-e cannot here 

 stop to particularise. — M. Valerius, in a note on binocular, as 

 compared with monocular, vision, comes to the conclusion that 

 the proportion of brightness of an object, looked at successively 

 with both eyes, and with one, is nearly independent of the abso- 

 lite amount of illumination: and with ordinary candle or gas 

 flame, does not exceed i ■15. He afterwards found that his left 

 eye was less sensitive than the right ; had he used the latter, 

 the proportion in question would be somewhat less. The mea- 

 surements were made with Foucault's photometer. — M. Kundt 

 contributes a paper on the vibration of rectangular, and espe- 

 cially of square, air plates ; meaning, by an air plate, a thin 

 layer of air enclosed between two solid plane plates applied to 

 each other (it may I e either in communication with the external 

 air, or closed all round). He makes the vibration-forms visible 

 by means of cork powder; and the present communication chiefly 

 shows that the vibration-numbers observed in the entirely-closed 

 air plates agree with those deduced from theory, to less than 

 I per cent. — Dr. Hiibener gives an account of researches on 

 transpiration of salt solutions through capillary tubes. The velo- 

 city of outflow is found to be inversely as the equivalent weights ; 

 which may be explained (the author thinks) by the fact, that in 

 compounds with hiyh equivalent weight the molecules are lai-ger 

 than in those with k-w. If, then, equal weights of two salts of 

 different equivalent weight bo dissolved in a liquid, there will be 

 present in the solution of the heavier salt larger but fewer mole- 

 cules than in the other solution. Hence, in the solution of the 

 first salt, the molecular surface in contact with the solvent will 



be less than in the second liquid ; and the internal friction will 

 be less ; thus (other conditions equal), there will be greater mo- 

 bility. — A paper by Dr. Dibbits discusses, at some length, the 

 dissociation of ammonium salts in aqueous solution ; the results 

 detailed being both qualitative .and quantitative. — M. Ram- 

 melsberg communicates a second note on natural compounds of 

 tantalum and niobium ; and Dr. Bender describes an ingenious 

 method of determining the time of vibration of a material pen- 

 dulum. The remaining matter does not specially call for 

 notice. 



. SOCIETIES AND ACADEMIES 



Royal Society, Feb. 5, — "On the Anatomy and Habits of 

 the genus Phronima (Lattr.)." By Dr. John Denis Macdonald, 

 F.R..S., Staff Surgeon R.N., Assistant Professor of Naval Hy- 

 giene, Netley Medical School. 



Of all groups of Crustacea the Amphipoda would appear to 

 exhibit the widest range, in the modification of their parts or 

 organs, without obliterating the delicate lines of natural affinity 

 running through them as a whole. This is well exemplified in 

 the interesting paper of Dr. R. Willemoes-Suhm, naturalist to 

 the Challenger Exploring Expedition, " On anew Genus of Am- 

 phipod Crustaceans " founded by him, and named Thaunwps. 

 This genus, although exhibiting many characters in common with 

 Fhronima, presents some striking points of difference traceable 

 in the external jaw-feet, caudal appendages, the position of the 

 generative bone, and certain particulars in its external anatomy. 



During the exploi-atory voyage of H.M.S. Herald, in the S.W, 

 Pacific, numerous species which I have always been in the habit 

 of referring to the genus Phronima, were taken in the towing- 

 net ; and I might remark that the assumed parasitic habit of 

 these creatures was never, at lenst, a prominent fact to me, they 

 were so often taken either perfectly free, or tenanting anidamental 

 case. Those who, like Dr. Suhm, are acquainted with deep-sea 

 dredging, are usually cautious how they refer the doubtful pi'oducts 

 to their proper habitat ; whether it be the bottom that has been 

 reached, or some zone of the watery space above. Indeed it is quite 

 possible for the narrow area of the tallow-arming of the deep-sea 

 lead to include fortuitously, and carry down Phronima or any 

 other little crustacean naturally living near the surface ; and con- 

 tact with the bottom would finally press it into the tallow, so as 

 to misleael the ob;erver as to its true habitat. Conversely, in 

 bringing up the dredge from a given depth, it may finally carry 

 with it any more superficial objects casually lying in the track 

 which it taiies. 



The author then describes a species of P/ironima captured in 

 lat. 30° i6' S., long. I76'> 27' W. 



The evidence of Dr. Willemoes-Suhm supports my own expe- 

 rience that there is no metamorphosis in this group ; and as it is 

 very probable that the history of the development of Thanmops 

 would resemble that of Phronima, the following observations 

 may be of some importance, as carrying the process a little 

 further than it has perhaps yet been traced by him : — 



In lat. 21° o' S. and long. 17° 45' W. off the island of Ono, 

 Fiji group, apparently the same species of Phronima as that above 

 referred to was taken in the towing-net, but wi*h the addition of 

 a numerous progeny of young in a large gelatinous but tough 

 nidamental case. This interesting nest was shaped like a barrel, 

 but with both ends open, and the external surface was somewhat 

 tuberculated and uneven. The wall of the tube presented nume- 

 rous round and puckered openings, observing no very definite 

 arrangement, but through which entering currents were observed 

 to pass. These openings in general pierced the tuberculations, 

 though not invariably. 



An external membrane, with an internal lining, was distinctly 

 visible, both seeming to be continuous at the rims of the tube. 

 The space between these byers was filled up with a pulpy sub- 

 stance, in which scattered nucleiform bodies were detected with 

 a higher power of the microscope. 



In a subsequent commission on ihe North-American and West- 

 Indian Siatiun in H.M.S. learns, I have frequently captured 

 " Phronima in its bay," as my messmates would say. In order 

 to bring the swjnmerets into full play, the animal protrudes its 

 booy tail foremost trom the case, only calling into use the fine 

 tips of the tliird and fourth pairs of thoracic limbs to hold fast 

 its charg;. When it fully retires into the case, the claws of the 

 two posterior pairs of legs are pressed backwards against the 

 lining membrane, so as still more effectually to secure its hold on 

 the approach of danger. 



