1 8 



NATURE 



[May i, igr 



(2) The surface water must be of approximately 

 the same salinity as that of the sea bottom ; if 

 it has a much lower salinity, its density may not 

 be increased by a reduction of temperature to 

 an extent sufficient to set up convection move- 

 ments reaching to the sea-bottom. (3) It must 

 be cooled to a slightly lower temperature than 

 that of the water at the sea-bottom, for its 

 adiabatic contraction, by pressure, as it sinks, 

 must warm it slightly ; this may be the cause of 

 the slight increase in the temperature of oceanic 

 water as we approach great depths — an increase 

 which has been attributed to the emission of haat 

 by radio-active substances in the oceanic bol>am- 

 deposits. (4) The formation of ice on the sea- 

 surface may favour convection currents by raising 

 the salinity of the superficial water ; but this is 

 not an important factor. 



The cold bottom water of the North Atlantic 

 Ocean originates in a restricted area of sea, out- 

 side the boundaries of the southerly-flowing polar 

 current, and lying to the south-east of Greenland. 

 Some of this water may also proceed from the 

 surface of the Norwegian Sea after flowing over 

 the Faroe-Iceland ridge. 



Incidentally Dr. Nansen directs attention to 

 the presence of Mediterranean water in the 

 channel between Ireland and Rockall. This 

 originates from warm and dense water flowing 

 out as an intermediate current through the Straits 

 of Gibraltar. The presence of this water in British 

 seas was pointed out by Dickson in 1909 as the 

 result of observations made in 1903 by Wolfen- 

 den. Dr. Nansen in 1909 referred to the methods 

 of these observations as " so inaccurate as to be 

 of little use." Nevertheless, he now adopts the 

 conclusions drawn from them, without, however, 

 referring to Dickson's prior discoverv. 



J- J- 



SOUTH AFRICAN INSTITUTE FOR 

 MEDICAL RESEARCH. 



SOUTH AFRICA has decided to have an insti- 

 tute for medical research on the same lines 

 as the Pasteur Institute in Paris, the Lister Insti- 

 tute of Preventive Medicine in London, or the 

 Rockefeller Institute in New York. To this end 

 a new building is now in process of erection in 

 Johannesburg, and is expected to be complete in 

 about twelve months. 



A site has been provided by the Government, 

 and we understand that the cost of building and 

 equipping the new institute will be provided by 

 the Witwatersrand Native Labour Association. 

 The maintenance of the institution will be under- 

 taken by the Government of South Africa and the 

 association in equal shares. 



A very satisfactory feature of the institute will 

 be its close proximity to the largest hospital in 

 South Africa, with which it is intended that it 

 should work in conjunction. It will also be 

 equipped with four wards for the purpose of 

 treating patients, who will be the subject of special 

 study. 



NO. 227O, VOL. gi] 



From the present plans, the institute seems to 

 be suitably arranged, and will be an imposing- 

 structure. It will comprise, in a main block, form- 

 ing a two-storied quadrangle, the institute offices, 

 experimental and observation hospital, animal 

 house, mortuary, and director's house. Ample 

 space is allowed here for future extension. Of this 

 main block the northern and southern sides are 

 prolonged eastwards and westwards to form two 

 further quadrangles. These will contain the hos- 

 pital wards and research laboratories, also librarv 

 museum, and further laboratories. The buildirio- 

 will carry as well a lecture theatre, basement work- 

 shops and storage rooms, and a number of rooms 

 for miscellaneous scientific purposes. A dome 

 eighty feet in height will crown the building, and 

 will carry a finial emblematic of the surrender bv 

 Death of his secret, and we understand that a 

 second dome of equal magnitude is aspired to. 

 Although we realise that an institute which is 

 intended to render valuable service to the State 

 should be housed in fashion suitable to the import- 

 ance of the work it is to undertake, we sincerely 

 hope that contemplation of the domes and 

 the finial will not distract the attention of the au- 

 thorities from the fact that the success of their 

 scheme will essentially depend upon the personnel 

 of the staff and the funds made available for scien- 

 tific investigation. 



The research work of the institute is, we under- 

 stand, to be primarily directed towards the indus- 

 trial diseases of the Transvaal, but all diseases 

 will come under its scope. It is intended that 

 research fellowships shall be available for medical 

 men, in order that they may carry out special 

 lines of investigation; also it is hoped that in the 

 near future medical students will be enabled to 

 undertake courses in pathology and bacteriology 

 at the institute, of a character which can now 

 only be attended in Europe. 



Two appointments to the staff of the institute 

 have already been made : the director of the insti- 

 tute will be Dr. Watkins Pitchford, and the 

 statistician Dr. G. D. Maynard, both of whom 

 have already accomplished sound work in con- 

 nection with one or other of the public health 

 organisations of the colonies now forming the 

 Dominion of South Africa. 



EDUCATION OF THE AUDITORY 

 CENTRES. 1 

 DROF. MARAGE, who is well known as an 

 -*- otologist and for his researches in physio- 

 logical acoustics, has issued a small but suggestive 

 pamphlet on what he terms the education of the 

 auditory centres. It is known that there are 

 cases in the clinique of the aurist where there 

 is sensitiveness to even feeble noises while there 

 is deafness to music and to speech. In others 

 the patient may hear noises, music, and even 

 speech sounds, but without any understanding of 

 the meaning of the speech sounds. Prof. Marage 



1 " Education et Reeducation des Centres auditifs." By Prof. Marage. 

 Pp. 15. (Paris, 19 Rue Cambon.) 



