August 23, 1895.] 



SCIENCE. 



229 



its discussion of structural and petrograph- 

 ical problems, it is of use to the physiogra- 

 pher also in giving excellent description 

 and illustration of typical examples belong- 

 ing to this peculiar member of the volcanic 

 group of forms. It may thus serve as a cor- 

 rective to the undue share of attention or- 

 dinarily allowed to the superficial loose- 

 textured and short-lived volcanic cone. It 

 serves also to enforce the idea that the sur- 

 face of the land as we see it is often deeply 

 carved in land of earlier times ; triily a 

 primitive geological conception, but one 

 which geographers have been slow to re- 

 cognize and utilize. 



THE ETIN-OFF OF RIVERS. 



The same report of the survey contains a 

 chapter by F. H. Newell on the results of 

 stream measurements, in which an impor- 

 tant relation is indicated between rainfall 

 and topography, on the one hand, and ' run- 

 off,' on the other. For example, where the 

 mean annual rainfall on mountainous re- 

 gions is 40 inches, the run-off approaches 

 30 inches ; where the rainfall is 25 inches, 

 the run-off is 15 ; where the raiafall is 12, 

 the run-off is only 5. On more open coun- 

 try, where the mean annual rainfall is 50 

 inches, a run-off of 25 inches may be ex- 

 pected ; where the rainfall is 30 inches, the 

 run-off is about 8 inches ; while where the 

 rainfall is 20 inches, only about 3 inches 

 gets into the streams. In both mountainous 

 and open country, the percentage of run-off 

 rapidly decreases as the rainfall lessens. 

 One notable exception to this rule is noted. 

 In regions of small rainfall, under twelve 

 inches, the rain usually falls at long inter- 

 vals, but then at an excessive rate, often as 

 'cloud bursts.' In such cases the water 

 has little time to penetrate the ground, and 

 the run-off is exceptionally large. An in- 

 teresting map of the mean annual run-off of 

 our country accompanies this essay. 



W. M. Davis. 

 Haevaed Univeesiiy. 



SCIENTIFIC NOTES AND NEWS. 

 THE BRITISH MEDICAL ASSOCIATION. 



The sixty-third annual meeting of the 

 Association convened in London on July 

 30th, with an attendance of nearly 3000 

 members. The growth of the Associa- 

 tion in recent years has been remarkable. 

 "When it last met in London (1873) the 

 membership was 1500, whereas now it is 

 the strongest medical society of the world, 

 having 15,669 members and property of 

 great value. The address of the president, 

 Sir J. Russell Reynolds, was entitled ' The 

 power of life in life,' and discussed in part 

 the use of ' living things ' in the conser- 

 vation of health and the prevention or 

 cure of disease. The address also re- 

 viewed the progress of medicine since the 

 preceding London meeting and the rela- 

 tions of professional life to certain aspects 

 of art and religion. The Association met 

 in fifteen sections, before each of which 

 many papers were presented, followed by 

 discussions of much interest, not only to 

 members of the medical profession, but also 

 to all interested in the progress of science. 

 The Association occupies somewhat the 

 position of a professional trades union, and 

 with its great membership and means and its 

 organ. The British Medical Journal, is able to 

 influence, not only the etiquette and practice 

 of the profession, but also legislation. The 

 reports of committees, such as that on 

 Parliamentary bills, and the discussions that 

 followed, were consequently of great prac- 

 tical importance. 



SECTION O, CHEMISTRY, OF THE A. A. A. S. 



The committee appointed by the Council 

 to prepare a programme for the meetings 

 announce that the Committee after care- 

 ful consideration believe that added interest 

 may be given to the meetings by providing, 

 in addition to the original papers that may 

 be offered, a series of discussions of sub- 

 jects of current interest to chemists, in 



