Oct. 5, 1883.] 



♦ KNOWLEDGE ♦ 



209 



AN ILLUSYRATED \Jt 



MAGAZINE OF SCIENCE ^ 



^PLAINIXVfdRDED-£XACTl)f DESCRIBED 



LONDON : FRIDAY, OCT. 5, 1883. 



Contents of No. 101. 



BRITISH ASSOCIATION SCRAPS. 



N a paper read before the JSIatheniatical and Physical 

 section, Professor Chandler Roberts remarked on the 

 rapid diil'tision of molten metals. The two metals chosen 

 were lead and gold enclosed in a U-shaped tube, the lead 

 occupying the lower portion of the tube, and the gold 

 beiug put in at the top of one limb. After about forty 

 minutes Professor Roberts found that the two metals had 

 been thoroughly mixed. Sir \V. Thomson called attention 

 to the extreme importance of this, with reference to metallic 

 alloys, and remarked that it resembled the difl'usion of 

 gases or of heat in a gas rather than of a solid in a liquid. 

 Salt would take years to dill'iise in a similar manner through 

 water. 



A PAPER was read which had been received from two 

 American gentlemen, Messrs. W. B. Scott and 11. F. 

 Osborne, upon the " Origin and Development of the Rhi- 

 noceros Group." These gentlemen have made careful re- 

 searches in the extensive series of tertiary lake deposits in 

 the North- Western United States, in which specimens of 

 very many animals have been discovered, which render it 

 possible satisfactorily to trace the genealogy of several im- 

 portant groups of mammals. These gentlemen have dis- 

 covered the remains of the ancestor of the ihinoceros 

 group — an ancestry from which it is found that both the 

 rhinoceros and the tapir groups are descended. This 

 animal has been named Orthocynodon. A somewhat do- 

 tailed account of the anatomy of the skull and form of 

 dentition was given, bearing out the auth 'rs' views. 



The committee on ^Meteoric Dust state that Mr. Pope 

 Ilennossy had obtained a quantity of ice and snow from 

 the Himalayas. After lieing melted and boiled down the 

 residue was sent to England for examination. In most 

 specimens of the dust arc^ a number of small spherical 

 bodies of magnetic matter, the surfaces of which are 

 generally highly polished. Dr. Schuster showed several of 

 these particles, the largest being perhaps one-twentieth of 

 a millimetre in diameter, which had been obtained from a 

 Gpot in the Himalayas about 3,400 ft. high and It miles 

 from any human habitation. 



Sir R. W. Rawson stated that, according to the obser- 

 vations of the Anthropometric Committee, it appeared that 

 from the top of the social scale to the bottom there was a 

 gradual descent in stature, weight, chestrgirth, and all the 

 elements of strength. It was therefore of the utmost 

 importance that by nurture and improvement of sanitary 

 conditions the lowest should be raised to the level of the 

 highest. 



Dr. Schuster read an interesting paper on the motion 

 of the Swiss glaciers. It has been known for some time 

 that there are long periods of time during which the Swiss 

 glaciers advance down or recede up their beds. Thus, in 

 1741, they were advancing, but it was reported that in 

 1700 it was possible to walk from Chamounix to Cour- 

 meyer over the Col de Gt-ant without touching ice. They 

 advanced all last century as far as is known and up to 

 1817, then went back until 1840, advanced till 18-59, and 

 have since been receding till the present year, when many, 

 including the Mer de Glace and the Kosenlaui glacier, 

 have begun to advance. Dr. Schuster has made ob- 

 servations this summer on the Glacier des Boissons, at 

 Chamounix, and has arrived at the important con- 

 clusion that the rate of motion of the same point 

 on a glacier changes greatly from day to day. Thus he 

 showed that while during the day the hourly rate of 

 motion of one point observed was only G centimetres, 

 during the next night it advanced at the rate of 5 .5 centi- 

 metres per hour. The rate of other points examined varied, 

 but not so greatly. Dr. Schuster also noticed the change 

 occurring at the foot of the glacier when it comes into the 

 valley. The downward motion of this point is determined 

 by the fact that the parts above advance more quickly 

 than the ice at the foot melts away. He found tliat on 

 one side of the glacier, where it rested against a boulder, 

 there was no apparent change in the outline of the ice or 

 in the position of the boulder during the day, while at the 

 other side the end had moved in the same time four or five 

 feet. 



A PAPER was read by Mr. E. B. Poulton on heredity in 

 cats with an abnormal number of toes. The peculiarity 

 appeared in the third generation and in succeeding genera- 

 tions. All varieties between the normal four and the extreme 

 seven toes had been observed. The females most frequently 

 possessed the abnormal number of toes. They were very 

 clever at catching mice, and readily learnt to shake hands. 

 The President said the importance of such observations lay 

 in their bearing on heredity. Reasons had been advanced 

 to show that man was descended from a six-fingered animaL 

 Miss Buckland said she had seen in Bath a cat with seven 

 toes on each foot. Professor Marshall remarked on the 

 importance of such observations in relation to investigations 

 as to the origin of species. 



Mr. Adam Sedgwick gave an account of the Periodatus 

 — a slug-like animal which he found in South Africa, and 

 of which he exhibited specimens. The animal, he said, 

 had only recently been discovered, and he made a special 

 visit to the Cape to obtain specimens. Special interest 

 attached to it, as it had no living relations in the animal 

 kingdom. It was a survival of a type of animal which at 

 some ancient time in tlie world's history was represented 

 by a greater number of forms. The animal lived in the 

 roots of rotten trees, and it had probably survived on 

 account of its habit.-* and the dilliculty of finding it. Since 

 its iirst discovery the animal had lieen found in New 

 Zealand, South America, and other parts of the world. 



