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SCIENTIFIC NEWS. 



[Nov. 2, 1888. 



blocks of gneiss in the midst of a volcanic district, even 

 at some distance from the coast, and has drawn the con- 

 clusion that they were erratic blocks, brought by ice- 

 bergs. In Humboldt we find mention of a different view 

 quoted from Simroth in the Globus. The inhabitants of 

 Terceira state that these stones have been brought by 

 ships as ballast, and have been used by the country- 

 people for building their houses and garden-walls. This 

 view is supported by the fact that the two spots where 

 these stones have been found are not on the north side 

 of the island, where ice-bergs would be stranded, but on 

 the south and east coasts. The Azores have probably 

 never been glaciated. Simroth was unable to find marks of 

 glaciation even on the Pico, 7,000 feet above the sea-level, 

 where snow falls every winter. 



Action of Electric Currents upon Delicate 

 Balances. — The Naturwisscnschaftliche Wochenschrift re- 

 marks that as delicate balances are often strongly affected 

 by very slight causes, such as trifling fluctuations ot 

 temperature or slight agitations, the question is justified 

 in how far such instruments, as containing iron or steel, 

 are disturbed in their sensitiveness by electric currents. 

 The Central-Zeitung fiir Optik und Mechanik writes that 

 certain manufacturers have refused to introduce the 

 electric light in their establishments lest the current 

 should injure their balances. Hence, G. H. Terry, of 

 New York, has made a formal investigation of the 

 alleged influence. To this end he placed balances of 

 precision near very powerful currents and sought to 

 discover any irregularities. But nothing could be detected. 

 The balances contained very little iron or steel. For 

 greater certainty he therefore placed a piece of iron in 

 one scale and brought very near it a conductor traversed 

 by a powerful current. No action was perceived until 

 the current was brought within 3 millimetres of the iron. 

 From these researches it follows that the currents used 

 in electric lighting can have no effect upon balances of 

 precision. 



The Pine Forests of Western France. — In a report 

 on the agriculture of the Gironde, the British Consul at 

 Bordeaux refers to the forests which cover about a third 

 of the department, especially the Landes district, where 

 the soil is wholly unfitted for ordinary cultivation. 

 Hence forests of pines {pin maritime) have in recent 

 times been planted, and the wood and resin obtained 

 from them have now become an important and, in some 

 instances, the sole source of revenue of the inhabitants 

 of those districts. In the parts distant from towns and 

 other inhabited places, resin is chiefly produced, while in 

 places nearer to Bordeaux or other shipping ports, where 

 means of transportation exist, the production of pit 

 props, rai'way sleepers, telegraph poles, and wood for 

 fuel forms the chief business. The collection of resin 

 affords n living to a large number of the very poorest 

 persons, a:id the recent decline in the exportation of this 

 article from Bordeaux has been a great misfortune to the 

 inhabitants of some parts of the Landes district. The 

 decline has been caused by the annually increasing com- 

 petition of the United States, which has become the 

 chief exporter of resin, to the almost entire exclusion of 

 Bordeaux. A new kind of oil, called pine oil, is now 

 made from the refuse of resin after the latter has been 

 employed in making turpentine. This is used as an 

 illuminant in some private houses in Bordeaux, and burns 



very brightly ; it is cheaper than refined petroleum, and 

 is not explosive. The trees do not appear to suffer by 

 the extraction of the resin, if it be done carefully, and 

 the wood is even better fitted then for certain purposes, 

 such as paper-making and the manufacture of pyrolig- 

 neous acid, than it was before. The export of pit props 

 made from the Landes pines is an important branch of 

 trade between Bordeaux and English ports ac'jacent to 

 coal districts. Railway sleepers and telegraph poles are 

 likewise made in large quantities in these pine forests ; 

 they are used chiefly in France. Besides, a large quan- 

 tity of young pine finds its way to England every year 

 to be converted into paper. The Landes is a sandy 

 district in which nothing but pines will grow, and the 

 forests are all of recent origin. 



The Public Health. — The Registrar-General's return 

 for the week ending Saturday, October 20th, states that 

 the deaths registered in 28 great towns of England and 

 Wales corresponded to an annual rate of 21*0 per 1,000 

 of their aggregate population, which is estimated at 

 9,398,273 persons in the middle of this year. The six 

 healthiest towns were Bradford, Brighton, Halifax, Hud- 

 dersfield, Hull, and Leicester. The highest annual 

 death-rates, measured by last week's mortality, were — 

 from measles, 1-3 in Blackburn and in Wolverhampton, 

 and i"9 in Leeds ; from scarlet fever, i - 6 in Sunderland 

 and in Derby, and 2 - 6 in Blackburn ; from whooping- 

 cough, i'o in Cardiff; from "fever," i'o in Preston, 1*2 

 in Salford, 1*4 in Bolton, and i - 6 in Birkenhead; and 

 from diarrhoea, 1*5 in Portsmouth, 2-5 in Preston, and 

 2-8 in Bolton. The 53 deaths from diphtheria in the 28 

 towns included 36 in London, and 6 in Manchester. 

 Small-pox did not cause a single death in any of 

 the 28 great towns. In London 2,459 births and 

 1,641 deaths were registered. Allowing for increase 

 of population, the births were 329 below, while the 

 deaths exceeded by 30 the average numbers in the 

 corresponding weeks of the last ten years. The annual 

 death-rate per 1,000 from all causes, which had increased 

 in the four preceding weeks from I5'8 to 18-7, further 

 rose last week to 20-0, and exceeded the rate recorded 

 in any week since April last. During the first three 

 weeks of the current quarter the death-rate averaged 18*4, 

 and was 0*3 below the mean rate in the corresponding 

 periods of the ten years 1S78-87. The 1,641 deaths in- 

 cluded 80 from measles, ^^ from scarlet fever, 36 from 

 fever, diphtheria, 12 from whooping-cough, 19 from enteric 

 1 from an ill-defined form of continued fever, 42 from 

 diarrhceaand dysentery,and not one from small-pox,typhu=, 

 or cholera ; thus 223 deaths were referred to these diseases, 

 being 19 above the corrected average weekly numbe 

 Different forms of violence caused 51 deaths; 45 weu 

 the result of negligence or accident, among which were 

 18 from fractures and contusions, 6 from burns and 

 scalds, 4 from drowning, 3 from poison, and 10 of infants 

 under one year of age from suffocation. In Greater 

 London 3,233 births and 2,004 deaths were registered, 

 corresponding to annual rates of 30-5 and 18 "9 per 1,000 

 of the estimated population. In the outer ring 10 deaths 

 from diarrhoea, 8 from diphtheria, 5 from measles, 

 and 5 from whooping-cough were registered. The 

 8 deaths from diphtheria included 2 in Godstone, 2 

 in West Ham, and 2 in Walthamstow sub- districts. Both 

 measles and scarlet fever also caused 2 deaths in West 

 Ham sub- district. 



