NOTES. 



43i 



that of mere chemical composition. Mr. F. 

 L. Garrison has found the microscope a very 

 useful test for determining the qualities of 

 metals, through the revelations which it af- 

 fords of the arrangement of their particles 

 and their structure. 



The British Association's committee to 

 observe the migration of birds has learned 

 that birds on their arrival at the British 

 Isles, as a rule, avoid high cliffs, and prefer 

 to enter river-valleys, whence they spread 

 gradually over the area embraced by the riv- 

 er's tributaries. 



Mr. E. W. Bccke has determined by 

 soundings the depth of the tubes of several 

 geysers of the Rotorua district, New Zea- 

 land. In the case of the extinct geyser of 

 Te Waro, he was let down the tube. At 

 thirteen feet below the surface it opened 

 into a chamber fifteen feet long, eight feet 

 broad, and nine feet high, from one end of 

 which another tube led downward to an 

 undetermined depth. The author was sat- 

 isfied, from his intercourse with the natives 

 of the district, that by constant observations 

 on the direction of the wind and the con- 

 dition of the atmosphere, they had learned 

 to prognosticate the movements in all these 

 hot springs with wonderful accuracy. lie 

 had also observed during his residence that 

 the geysers were in eruption only when the 

 wind blew from a particular quarter. 



Mr. Robert Capper proposed, in the Brit- 

 ish Association, a railway to connect the 

 heart of Africa with London in ten days, as 

 " a feat worthy of the age we live in." He 

 would advocate the building of a railway 

 from the two rivers Niger and Congo to- 

 ward each other, and north and south at the 

 rate of a mile a day, to form a spine through 

 the continent. It would give the missiona- 

 ries and traders two sides to work from, in- 

 stead of one, as now. 



Weeds are plants in the wrong place. 

 They all probably have their right places 

 and their uses somewhere in Nature's ecan- 

 omy, though these are sometimes hard to 

 appreciate. The most of them may serve 

 to keep some desolate spot from being cn- 

 tiely bare, and the decay of their repeated 

 generations furnishes mold to the ground, 

 and may in time make it fit to bear some- 

 thing better. They all, too, have elements 

 of beauty, and these will reveal themselves 

 to every one who diligently searches for them. 

 Many of them, if they were not weeds, would 

 be prized as choice flowers, and some of 

 them have been such. 



Commenting on the vital statistics of 

 one of the parishes of London, Dr. Mey- 

 mott Tidy calls attention to the fact that 

 the death-rate of England is decreasing, and 

 that 150 people are added yearly to every 



10,000 of the population. From this he 

 prognosticates that at the present rate of in- 

 crease the population of the country twenty 

 generations hence will be 27,200,000,000, 

 or enough, if distributed no more densely 

 than the present population, to fill twenty 

 earths. From 5,000,000 in the reign of 

 Henry VIII, the population of England rose 

 to about 7,500,000 in the early part of the 

 reign of George III, and then, under the im- 

 pulse of a long period of commercial pros- 

 perity, to 16,000,000 at the time of the re- 

 peal of the corn laws. Now, 24,000,000 

 people are housed and fed in England and 

 Wales, and depend on other countries for 

 half of their food. Dr. Tidy regards the 

 present increasing population and declining 

 trade as serious facts. 



Dr. J. Burnet Yeo mentions, as among 

 the special applications which are made of 

 the waters of the mineral springs of Conti- 

 nental Europe, the treatment of biliary ob- 

 structions and the plethoric forms of gout, 

 at Carlsbad ; of atonic gout, at Rogat ; of 

 calculous disorders, at Vichy and Contrexe- 

 ville ; of chronic articular rheumatism and 

 gout, at Aix-les-Bains ; of diabetes, at Neuc- 

 nahr and Carlsbad ; of obesity, at Marien- 

 bad ; of gouty and catarrhal dyspepsia, at 

 Hamburg and Kissingen ; of anaemia, at 

 Schwalbach and St. Moritz; of asthma, at 

 Mont Dorc ; of throat affections, at Caute- 

 rets and Eaux-Bonnes ; of scrofulous gland- 

 ular affections, at Kreuznach; and of the 

 great variety of chronic skin affections, at 

 Aix-la-Chapel!e, Cannstadt, La Bourbole, 

 and Uriage. 



Describing, in the British Association, 

 his optical studies in the essential oils, Dr. 

 Gladstone, after explaining how the refract- 

 ive equivalent of an organic compound 

 may be used to determine its constitution, 

 pointed out that the dispersive equivalents 

 can be similarly used. He also discussed 

 the refraction and dispersion equivalents of 

 the turpenes, citrenes, camphor, and some 

 other members of the group of essential 

 oils, and showed how their values are of 

 service in determining the constitution of 

 those bodies. 



n. R. Mill has determined the salinity 

 of the water from point to point in the Firth 

 of Clyde and the Firth of Forth. The dis- 

 tribution of salinity in the Firth of Forth is 

 constant all the year round, while periodi- 

 cal variations are observed through the 

 whole mass of the water in the Firth of 

 Clyde. It is evident that in the Forth River 

 entrance, a mixture of river- and sea-water 

 takes place by a true process of diffusion, 

 and a constant gradient is maintained from 

 river to sea. The dissolved matter of fresh- 

 er water was found richer than sea-water in 

 calcium carbonate. 



