Al'RIL 27, 1905] 



NA TURE 



62 1 



pressure. In spite of the ingenuity of this explanation, its 

 validity seems doubtful, for the stresses involved can at 

 most be only a subsidiary cause of earthquakes, and con- 

 sequently any effect due to them would naturally be looked 

 for at the time when they vary most rapidly in amount 

 rather than at that of their maximum. 



The same publication contains a paper, of some im- 

 portance in this connection, on daily periodic changes of 

 level in artesian wells, by K. Honda. It is the account 

 of a record, obtained by a self-registering instrument, of 

 the daily changes in level of two artesian wells, 380 metres 

 and 300 metres depth, in Tokio and Yokohama. Each 

 of them showed a periodic change of level which is 

 directly correlated with the tides in the neighbouring sea, 

 and also a variation due to changes in barometric pressure, 

 of such amount as' to show that one-third of the changes 

 in the first case, and one-fourth in the second, are absorbed 

 by the rocks overlying the water-bearing stratum. 



The catalogue of earthquakes felt in Austria during the 

 year 1903, forming No. 26 of the Mitteilungen of the 

 Austrian Earthquake Commission, is the last of the series 

 which will be published under the auspices of the Academy 

 of Sciences. In the introduction to the catalogue it is 

 announced that from the beginning of 1904 the task of 

 collecting and publishing the records of all earthquakes, 

 whether of local or distant origin, observed in Austria, was 

 taken over by the Zentralanstalt fiir Meteorologie und 

 Geodynamik. The Earthquake Commission, having pub- 

 lished the earthquake registers up to the end of 1903, will 

 in future confine itself to the encouragement and publi- 

 cation of purely scientific investigations. 



After the collapse of the campanile of St. Mark's, in 

 1902, there was a popular demand, inspired by the idea 

 that the detonation was likely to precipitate the destruc- 

 tion of other historic buildings in Venice, for the cessation 

 of the usual mid-day gun. The idea was, of course, un- 

 founded, but to allay the alarm Prof. Vicentini was re- 

 quested to instal one of his microseismographs, and his 

 report has now been published. The instrument was 

 attached to the wall of the ducal palace which faces the 

 lagoon and is directly exposed to the sound waves of the 

 cannon ; it indicated a vertical displacement, in conse- 

 quence of the report, of 0012 mm. to 0014 mm., and 

 a horizontal displacement of 0-007 mm. to 0012 mm., being 

 about one-half of those produced by a person jumping on 

 the floor of the room in which the instrument was in- 

 stalled, and one-fifteenth of the displacement caused by 

 a high wind. From these figures it is evident that the 

 sound waves of a cannon can have no appreciable effect 

 on a building, though plaster may be detached where this 

 has become loosened and separated from the wall by an 

 air space. 



SOCIETIES AND ACADEMIES. 

 London. 



Royal Society, February 23. — " The Colour-physiology of 

 the Higher Crustacea," Part iii. By F. Keeble and Dr. 

 F. \V. Gamble. Communicated by Prof. Svdney J. Hick- 

 son, F.R.S. 



(i) The chromatophores of Hippolyte and Crangon are 

 multicellular structures. Their branches show differenti- 

 ation into a firmer ectoplasm and a more fluid mobile 

 endoplasm in which the pigment occurs. (2) The form- 

 ation of the pigments in the larval and post-larval chro- 

 matophores is described. (3) In addition to pigments, fat, 

 in the form of colourless globules, occurs in the chromato- 

 phores of Hippolyte. This fat lies in special cells of the 

 chromatophore, and exhibits a mobility similar to that of 

 the pigments of the chromatophore. (4) If fed and kept 

 in the dark, or if starved and kept in the light, Hippolyte 

 loses little of its chromatophoric fat. Depletion of fat 

 occurs, however, in starved, dark-kept animals. These, 

 when exposed to sunlight for five or six hours, show fat 

 in their chromatophores. These results show that the 

 colourless chromatophoric fat is a reserve food material, 

 and point to the conclusion that in the accumulation of 

 this reserve fat light plays an important part. (5) At the 

 time of settling on the weeds of the sea-shore, Hippolyte 

 various is a colourless or faintly brown-striped animal. 



NO. 1852, VOL. 71] 



At this stage it is extremely sensitive to the light con- 

 ditions of its environment, assuming the colour of its 

 surroundings within twenty-four hours. If the environ- 

 ment be changed, sympathetic change of colour takes place 

 in three days. Half- and full-grown Hippolyte are less 

 susceptible. With them sympathetic colour-change occupies 

 a week or more. 



March 30. — " On the Distribution of Velocity in a 

 Viscous Fluid over the Cross-section of a Pipe, and on the 

 Action at the Critical Velocity." By J. Morrow. Com- 

 municated by Prof. H. S. Hele-Shaw, F.R.S. 



Summary and Conclusion. — (i) The experiments provide 

 a partial confirmation of the theoretically obtained law of 

 velocity distribution, but show that this distribution can 

 only be obtained under very special conditions, of which 

 absolute freedom from obstructions and end effects are 

 important ; and hence (2) When the flow is direct and 

 stream-lines exist, the velocity distribution is not necessarily 

 exactly that which may be described as characteristic of 

 " normal " flow. (3) At the critical velocity the irrota- 

 tional straight line motion ceases and is followed by one 

 in which the paths of the particles of fluid are eddying 

 and turbulent. The law of distribution of mean linear 

 velocity parallel to the axis simultaneously changes from 

 the parabolic (or approximately parabolic) to that typical 

 of eddying motion. (4) The critical velocity in question 

 (being that at which eddying motion ceases to be trans- 

 formed into direct motion, and not that at which a highly 

 unstable stream-line motion is suddenly disturbed) is not 

 accompanied by a sudden change in the velocity parallel 

 to the axis at any point in the cross-section. On the 

 other hand, as the total flux increases, the experiments 

 show a gradual transition from one state to the other, 

 due to the change which has occurred in the law of 

 velocity distribution. (5) The observations have little bear- 

 ing on the upper limit of stream-line flow, as observed 

 by colour bands. They indicate, however, that the un- 

 stable direct motion would follow an approximately para- 

 bolic law of velocity distribution (as represented by the 

 equation obtained for stream-line motion), and that at the 

 higher critical velocity this distribution would suddenly 

 change to that represented by the equation given for eddy- 

 ing motion. In this case, then, instead of a gradual 

 change of velocity, there would actually be sudden and 

 large changes in the velocity parallel to the axis at different 

 points in the cross-section of the pipe. (6) The " Pitot 

 law " (v= •y2gh) is at least approximately true at ex- 

 ceedingly low velocities. 



-April 6. — " The Influence of Cobra-venom on the Proteid 

 Metabolism." By Dr. J. Scott. Communicated by Sir 

 Thomas R. Eraser, F.R.S. 



Conclusions. — (i) Practically no change in rate of proteid 

 metabolism was induced by the administration of cobra- 

 venom, in spite of well marked local reaction. (2) A slight 

 decrease in the proportion of urea nitrogen, quite insignifi- 

 cant compared with that produced by diphtheria toxin and 

 various drugs, was observed. (3) A slight rise in the pro- 

 portion of ammonia nitrogen occurred. (4) There was a 

 slight rise in the proportion of nitrogen in purin bodies. 

 (5) The nitrogen in other compounds showed no constant 

 change. (6) The P,Oj excreted showed no constant change, 

 but in two experiments there was a slight rise. The change 

 produced in the proteid metabolism is, therefore, small, 

 and such as it is, being in the directions of decreased 

 elaboration of urea and increase in the proportion of 

 nitrogen excreted as ammonia, it seems to indicate a slight 

 toxic action on the hepatic metabolism rather than a 

 general action on the proteid changes, and tends to con- 

 firm the view that the poison acts chiefly upon the nervous 

 system. 



Entomological Society, April 5. — Mr. F. Meriifield, 

 president, in the chair. — Specimens of a melanic Grammo- 

 ptera, discovered by Mr. J. C. T. Poole at Enfield, and 

 apparently quite distinct from any member of the genus 

 taken in'Brltain: H. St. J. Donisthorpe. Mr. Gahan, 

 to whom the species had been referred, considered it to 

 be a form of G. ruficornis. — A specimen of Megalopus 

 melipoma, Bates, an insect which so much resembles a 

 bee that Bates had said they were indistinguishable in 



