March 25, -1887. J 



8CIEJSICE. 



301 



CURRENTS IN THE BOSPHORUS. 

 Captain Makarof of the Russian navy has 

 given an account, in the Sapieski of the academy 

 at St. Petersburg, of his observations on the cur- 

 rents of the Bosphorus, made between November, 

 1881, and August, 1883, which reaches us through 

 the highly valued Annalen der Hydrographie of 

 the German admiralty. The surface current, from 

 the Black Sea to the Sea of Marmora, follows the 

 windings of the strait, with occasional backset 

 eddies near the shore : its velocity averages two 

 knots an hour, and reaches a maximum of four 

 knots. The velocity has a maximum in summer 

 corresponding to the higher level of the Black Sea 

 in that season and a faint maximum about noon, 

 supposed to be due to the diurnal increase of the 

 north-east wind. The undercurrent carries the 

 denser water of the Mediterranean into the Black 

 Sea : its water has a specific gravity of 1.02834, 

 vphile that of the surface is 1.01534. The plane of 

 contact of the two has a greater inclination to- 

 wards the Black Sea : at Constantinople it is 

 tvpenty metres under the surface ; at the north- 

 eastern end of the Bosphorus it is fifty metres 

 deep. This is shown more in detail in the follow- 

 ing table : — 



cross-sections of the two currents, it is estimated 

 that the Bosphorus annually carries 153 cubic 

 kilometres of water from the Black Sea. 



MENTAL HYGIENE. 



There appears to be a variation in the depth 

 of the contact plane with the seasons, but it is to 

 be remembered that this depends on only one 

 year's observations. At nine kilometres from the 

 Black Sea, water of a specific gravity of 1.0335 

 was found in the middle of June at 43 metres ; at 

 the beginning of July, 41.5 ; end of July, 40.5 ; 

 end of August, 34.7 metres. It is suggested that 

 this variation depends on the height of the water 

 in the Black Sea. The greater its height above 

 that of the Sea of Marmora, the less the difference 

 of pressure at the bottom of the strait, and thus 

 the less cause for the deep counter-current. The 

 velocity of the upper current is greatest at the sur- 

 face ; at the limit between the two currents, the 

 two velocities just counteract each other ; the 

 maximum velocity of the lower stream is found 

 at five and a half metres below this neutral sur- 

 face. By considering the mean velocities and 



One important element that contributes to the 

 high position that Germany occupies in the world 

 of science is the existence of a large class of sci- 

 entists devoted to a specialty, but with an intelli- 

 gent and cultured interest in many topics lying 

 more or less remotely outside their own branch. 

 In this way an appreciative public is guaranteed 

 for an 'atechnical' treatment (to use Hamerton's 

 word) of one's own specialty. This is synony- 

 mous with the good sense of the word ' popular,' 

 but it is the very opposite of much that goes by 

 that name here. It is a concise and easy treat- 

 ment of a subject, without neglecting the difii- 

 cult points, or sifting out the interesting things to 

 be served in a highly diluted form. Another en- 

 viable peculiarity of German science closely con- 

 nected with the former is the ability to treat a 

 subject from (there is no better word for it) a 

 philosophic point of view ; to bring it into rela- 

 tion with the questions that always have inter- 

 ested and always will interest mankind. As the 

 physicians everywhere form the largest body of 

 professional scientists, it is an especially enviable 

 state of things when all this (as it is in Germany) 

 is true of them. An excellent illustration of this 

 fact is shown in this book by Dr. Schulz. He is 

 writing upon his specialty in a perfectly clear and 

 yet entirely scientific manner, feels confident of 

 finding an appreciative public, and has shown 

 an important connection between the teacher and 

 the doctor. 



The problem of civilization is to the alienist the 

 problem of keeping sane. At no time was op- 

 timism so justifiable a faith as it is now. Com- 

 fort, liberty, philanthropy, education, and all the 

 aids to happiness, are more wide-spread now than 

 ever before. And yet we do not enjoy our hap- 

 piness. Discontent is found everywhere. Why 

 is this ? Primitive man used muscle and nerve as 

 his chief tools, just as we do ; but formerly it was 

 the muscle, now it is the nerve, that has the most 

 to do. The work that modern culture demands 

 is, above all, brain-work. The higher the civiliza- 

 tion, the more the brain has to do. This delicate 

 organ has become overtaxed. The onward march 

 has been too rapid to give us time to get fully 

 adapted to our surroundings, and an intense strug- 

 gle for existence is the result. In this struggle 

 many fail, and hence our age is called an * age 

 of nerves ' {nervoses Zeitalter) : hence the alarm- 

 Die Didtetik des Geistes. Von Dr. Feibdebich Schulz. 

 Leipzig, 



