332 



NA TURE 



[February 6, [908 



Mr. Solomon often succeeded in taking as many as 500 

 per minute. In this process some hundred shells are 

 exposed at a time to the rays. The oysters, spread on 

 trays, are carried under the specially constructed 

 cylinders by means of an electric motor. These great 

 cylinders are cooled by means of suitable w?ter jackets, 

 and can thus be kept working continuously. 



The oysters in which there is no sign of pearl forma- 

 tion are put back to their beds. Those in which good- 

 sized pearls are detected arc removed and opened, and the 

 pearls promptly utilised. Those showing no pearls of 

 adequate commercial value, but containing promising 

 seed or immature pearls, are carefully placed in hospital. 

 This hospital has rather a novel object ; not the cure of 

 the_ pearl disease (for the much prized gem is but a patho- 

 logical growth), but, on the contrary, everything is done 

 to keep the mollusc in stulu quo ante so that the disease 

 may progress as rapidly as possible to the production of 

 valuable pearls and to the death of the incurable patient. 



The question seems to arise, can the normal, or perhaps 

 vcc should say the abnormal, conditions of the pearl- 

 producing bivalve be well enough imitated in captivity to 

 ensure the continued growth of the pearls? May not the 

 ■"change of water" (as they must be kept nearer the 

 surface) secure for the sufferers immunity from their 

 diseased process? One might have imagined that a 

 ■greater amount of sunlight, more oxygen, altered tempera- 

 ture, different nutrition, lessened pressure, and other 

 changed conditions we think not of, would so influence 

 the life of the mollusc that it might depart from its 

 pathological but useful habit of producing these valued 

 round bits of shell material, and the hospital might thus 

 prove a true Kur-Anstalt instead of a pearl-breeding 

 dep6t. But Mr. Soloinon tested these points, and he has 

 satisfied himself that, if he can be certain to transmit in 

 all circumstances the oysters to and from his laboratorv 

 without injury to their well-being, all other difficulties 

 Viave^ already been overcome. As to the lucrative com- 

 mercial value of the undertaking, time alone can tell ; 

 sufficient ha^ not yet elapsed to make it demonstrable bv 

 actual proof that pearls can thus be hatched en gros. 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE. 



Cambridgi!. — Two Graces will be offered to the Senate 

 at the Congregation on Thursday, Februarv 13 ; the first 

 gratefully accepts the generous offer of the Drapers' Com- 

 pany tp contribute a sum of 200/. a year until igiq towards 

 the stipend of a second professorship in the department 

 of agriculture, and the second establishes in the University 

 a professorship of agricultural botany. 



The council of the Senate has reported that it is ol 

 opinion that the University should hold a Darwin celebra- 

 tion in the course of the year 1909. The council points 

 out that Charles Darwin was born on February 12, 1809, 

 and that the " Origin of Species " was published ori 

 November 24, 1859. The hundredth anniversary of the 

 former event, and the fiftieth anniversary of the latter, will 

 therefore fall in the course of the ve.ar 1909. It is' sug- 

 gested that representatives of universkios and other learned 

 bodies, together with distinguished individuals, should 

 receive invitations to visit the Universitv on the occasion. 

 Should this report bo confirmed by the .Senate, the council 

 will appoint a committee to consider the details of the 

 proposed celebration. The week beginning June 20, 1909, 

 appears to the council to be the most suitable time for the 

 celebration. 



London.— The degree of D.Sc. has been conferred on 

 Mr. H. B. Fantham for a thesis entitled " Spirochaeta 

 (Trypanosoma) balhianii (Certes) and Spirochaeta ano- 

 <ioH(ae (Keysselitz) ; their Movements, Structure, and 

 .Affinities," and other researches in zoology. 



Dr. Otto Stapf has commenced a universitv course of 

 ten lectures on "Grasses: their Structure, Biology, Dis- 

 tribution, and Classification," and Dr. Bcddard, F.R.S.. 

 a course pf four lectures on " The Circulatory System of 

 Reptiles." Both courses are being delivered at University 

 College on Mondays, the botanv lectures at 4 p;m. and 

 the zoology lectures at =; p.m., admission to these lectures 

 being free. 



NO. TQ97, VOL. yy] 



A university course of four advanced lectures in zoology 

 on " Tooth Development and Morphology " will be given 

 by Prof. H. \V. .Marett Tims, at Bedford College for 

 Women, at 5 p.m. on Tuesdays, commencing March 3. 

 Admission will be free. 



Arrangements have been made for university courses 

 in geology by Prof. Garwood, on " The (ieology and 

 Physiography of Arctic Europe " (in March) ; by Prof. 

 Seeley, F.R..S., on " The Thames and its Tributaries " 

 (in May); by Dr. Evans, on "Recent Advances in the 

 Determination of Minerals by Optical Methods " (in June) ; 

 and by .Miss Raisin, on " The Geological Structure of the 

 .Area of the Vosges " (in October). 



In future, a candidate for the D.Sc. degree may be 

 required by the examiners, as an additional test, to submit 

 within a given period a reasoned report on a subject 

 prescribed by them. Candidates for the B.Sc. honours 

 degree in mathematics as internal students are to be 

 allowed, under -certain conditions, to submit research work, 

 and such work will be taken into account in estimating 

 their qualifications. 



The Lord Alverstone, G.C.M.G., Lord Chief Justice of 

 England, will present prizes and certificates to students 

 of evening classes and the day college of the South-Western 

 Polytechnic, Chelsea, on March 13. 



The Board of Education has issued a return (325) show- 

 ing the application by local authorities of funds for higher 

 education in England and Wales during the official year 

 1905-6. It appears that the total expenditure on account 

 of education other than elementary during the year was 

 3,355,434/. Of this amount, 706,149!. was spent on 

 secondary schools and 234,182!. on pupil-teacher centres.. 

 On behalf of evening schools and institutions for higher 

 and technical education, 1,200,789!. was expended, and in 

 dav schools of similar scope 258,517!. Exhibitions and 

 bursaries at secondary schools, pupil-teacher centres, even- 

 ing and day technical institutions, accounted for 376,762!. 

 The training of teachers cost 71,910!., the salaries of 

 officers other than teachers 120,531!., and 150,660!. was 

 paid on account of loans. The part of the total amount 

 which was expended in Wales reached 214,185!., more 

 than half of which was devoted to secondary schools. 



SOCIETIES AND ACADEMIES. 

 London. 



Royal Society, November 21, 1907. — " Note on the Sensi- 

 bilitv of the Ear to the Direction of Explosive Sounds." i 

 By A. Mallock, F.R.S. V 



Soon after llic introduction of modern rifles, which give 

 their projectiles a velocity much higher than that of sound, 

 the author noticed that when standing in a position in 

 front of the gun, and not far from the line of. fire, the 

 sound seemed to come, not from the firing point, but 

 from some point considerably in advance of the gun. The 

 natural explanation seemed to be that the sound thus 

 heard was not that of the explosion itself, but was caused 

 by the wave-surface, which is generated in the air by the 

 projectile moving at a velocity higher than that of sound. 

 In i8q8 the author made observations at the ranges at 

 Broundown to see if the apparent directions agreed with 

 this supposition ; and in the present year he has again 

 made similar experiments in much more favourable circum- 

 stances. It is clear (if the source of the sound is due to 

 the wave caused by the projectile) that the apparent direc- 

 tion of the sound will be the normal to the wave-surface, 

 and that if the direction of this normal is known, the 

 velocity of the projectile, at the time that that particular 

 portion of the wave-surface was generated which ultimately 

 reaches the observer, can be calculated. 



These observations are now recorded, not as giving a 

 practical method of ascertaining the velocity of projectiles, 

 but as showing that the ear can distinguish with con- 

 siderable accuracy the direction of a sound which consists, 

 not of a train of waves, but, at most, of two waves only. 

 The figure gives the plan of the range and the stations 

 at which the observations were made. 



The arrows through these points show the direction of 

 the sound as judged by ear. Each arrow is the mean 



