3 8o 



NATURE 



{August 17, 1882 



ing matter from passing into solution), the Canton of Berne in 

 September, 1879, issued an ordinance, fixing as an upper limit 

 for potassium sulphate in wines so doctored, 2 grammes per 

 litre. Various complaints then arose from merchants, who 

 thought the regulation too stringent ; and the Direction of In- 

 ternal Affairs nominated a Commission, consisting of Herren 

 Lichtheim, Luch-inger, and Nencki to study the subject afresh. 

 In their report (Journal fur Prakl. Chan.) they come to the conclu- 

 sions (1) that the perniciousne^s of plastered wines even when they 

 contain more *hin 2 gr. sulphate of potassium per litre, is far 

 from being demonstrated indisputably. On the other hand it 

 remains proved that wines strongly plastered have sometimes 

 cau-ed slight accidents, and it results from our theoretic study 

 that the prolonged u^e of such a drink cannot be without pre- 

 judice to health ; (2) that we therefore do not think it well to 

 leave the trade in plastered wines without any contiol. While 

 recognising the difficulty of fixing an absolute limit for plastering, 

 they approve as sufficient that of the ordinance in question ; on 

 the one hand, it guarantees the public against il!ne-s from u-e of 

 wines too much plastered, and on the other it is not a heavier 

 fetter for the producer than similar prescriptions in France, 

 where the interest in tolerance of plastered wines is vastly greater. 

 Each buyer who lias ordered a natural wine should have the 

 right to refuse any wine containing more than o'6gr. neutral 

 sulphate of potassium per litre. The reporters are unable to 

 answer a question as to the action of plastered white wines on 

 the system as compared with red. 



The additions to the Zoological Society's Gardens during the 

 past week include a Macaque Monkey (Macacus cynomolgus) 

 from India, presented by Mr. F. Logie Pirie ; two Silver 

 Pheasants (Euplocamus nycthemerus) from China, presented by 

 Mrs. Haines ; a Peregrine Falcon (Falco peregrimu), European, 

 presented by Col. A. Brooksbank ; a Peregrine Falcon (Falco 

 pcrcgrintis) captured at sea off Ceylon, pre-ented by Mr. Tom 

 Broune ; six Common Kingfishers {Alcedo ispida), British, pre- 

 sented by Mr. T. A. A. Burnaby ; two Slow-worms (Anguis 

 fragilis), two Common Vipers (I'i/era berus), Briti.-h, presented 

 by Mr. Charles Taylor; a Mou-tache Monkey (Ccriopithicus 

 Cephas) from West Africa, two Common Ravens ( Con/us corax), 

 British, two Common Boas (Boa constrictor) from South America j 

 deposited ; two Shags or Green Cormorants (Plialacrocorax 

 eristatus), European, purchased. 



CLIMATE IN TOWN AND COUNTRY x 

 'THE speaker began by describing the construction and u.-es of 

 -*• the instruments with which he had studied the conditions 

 of climate, for many years past, in various parts of Europe. 

 For the determination of sun temperature, he used a thermome- 

 ter technically known as the blackened bulb in ■■actio laid in full 

 sunshine upon a sheet of white 1 aper. The shade or air tem- 

 perature was measured by an ordinary thermometer with a clear 

 glass bulb and a scale engraved upon the stem. This thermome- 

 ter was placed upon the same sheet of paper, and was shaded by 

 a small white paper arch which admitted of a free circulation of 

 air around the bulb. 



He then explained the terms "sun temperature," "shade tem- 

 perature," and "sdar intensity." By shade tem| erature is 

 meant the temperature of free air in full sunshine. Strictly it 

 ought to be ascertained without any shade at all ; for as soon as 

 a shade is produced, conditions are introduced which often 

 entirely baffle the object of the observer. The shade of a para- 

 sol has a different temperature from the shade of a tree, and this, 

 again, differs widely from that of a house. The temperature of 

 the shade of a sheet of tinfoil is quite different from that of a 

 sheet of writing paper. Indeed it may be truly said that every 

 shade has its own peculiar temperature. The following table 

 shows the effect of the area of shade, and of the quality of the 

 shading material : — 



1 Lecture delivered at the Royal Institution of Great Britain, February 

 10, 1882. by li. Frankland, Esq., D.C.L.. F.RS., MR. I., Professor of 

 Chemistry in the Normal School of Science. South Kensington Museum. 



Beneath larch tree ia"'5C. 



„ white parasol ... ... ... 25'o 



,, small white paper arch ... ... 3S"o 



,, small arch of bright tinfoil ... 45'2 



Thus shade temperatures, measured during ij{ hours of unin- 

 tenupted sunshine in the middle of the day, and w ithin a few 

 yards of the same spot, differed by no less than 25 '7 C. These 

 observations were, however, made at Pontresina, 5,915 feet 

 above the sea-level, and so w ide a range does notoccur at lower 

 altitudes. 



The most effective shading material is, obviously, that which 

 most 1 erfectly reflects solar heat ; and of all materials with which 

 he had experimented white paper was found to be the best, 

 white linen and zinc-white being nearly equal to it. The most 

 trustworthy shade thermometer, therefore, is one having its bulb 

 covered with a thin layer of one of these materials; or the 

 naked layer may be shaded by a small arch of ■ hite paper. 



The term "sun temperature," as commonly employed, has a 

 very vague meaning. If a body could be [laced in sunlight 

 under :uch circumstances as to absorb heat rays and emit none, 

 its temperature would soon rise to that of the sun itself. But, as 

 all gocd absorbers of heat are also good radiators, the elevation 

 of temperature caused by the exposure of even good absorbers 

 to lunl ght is comparatively small. Thus an isolated thermome- 

 ter, with blackened glass bulb, pilaced in sunshine, will rarely rise 

 more than 10° C. above the temperature which it marks when 

 screened from direct sunlight. Under these circumstances, how- 

 over, the thermometer loses heat not merely by radiation, but 

 also by actual contact with the surrounding cold air. If the lat- 

 ter source of loss be obviated, a much higher suu tetnperatureis 

 obtained. Thus, the blackened bulb enclosed in a vacuous clear 

 gla^s globe will sometimes, when placed in sunlight, rise as much 

 as 60" C. above the shade temperature, and a still higher degree 

 of heat may be obtained by expo ing to the ! un's rays the naked 

 1 lackened bulb of a thermometer enclosed in a wcoden box 

 padded with black cloth, and closed by a lid of clear plate glass. 

 Thus he obtained w ith such a box, on the 22nd of December, in 

 Switzerland, when the a>r was considerably below the freezing 

 point, a temperature of 105° C, and a still higher temperature 

 could doubtless be obtained by surrounding the thermometer with 

 a vacuous globe before enclosing it in the padded box. These 

 widely different temperatures, produced under different condi- 

 tions by the solar rays, show that such observations can be com- 

 parative only when the thermometer employed to measure them 

 is always surrounded by the same conditions. All the sun tem- 

 peratures here mentiontd were measured when the "blackened 

 bulb in vacua" was laid horizontally upon a sheet of white 

 paper with its stem at right angles to the direction of the sun's 

 raj :-. 



" Solar intensity " is relative only, and means the 1, umber of 

 degrees through which the sun raises the temperature of a black- 

 ened bulb in vacuo over the shade temperature. Hence the two 

 temperatures mu-t be observed simultaneously, which is a labo- 

 rious operation when continued half-hourly throughout the day. 

 By the use of a peculiar self-registering differential thermometer, 

 however, which he had recently described to the Royal Society 

 (Proceedings of the Royal Society, 1SS2, p. 331), the naximum 

 solar intensity during the day is recorded by ore reading only. 

 The solar intensities commented upon in this disccurse were 

 ascertained by subtracting, in each case, the shade temperature 

 from the sun temperature taken synchronously. The precautions 

 necessary are described in the paper to the Royal Society just 

 quoted. 



The chief things affecting climate are the following : — (1) The 

 sun. (2) Land and water — ocean and atmospheric currents. 

 (3) Aspect — slope of ground, exposure or shelter. (4) Nature of 

 surface. (5) Reflection from land and water. (6) Rain and 

 clouds — suspended matter in the air. (7) Latitude — incidence of 

 solar rays, thickness of air. (8) Presence or absence of aqueous 

 vapour. Of these, the first three are obvious and require no 

 comment. The remainder are less well known, but their im- 

 pottance demands our special attention. 



Climate, or rather genial climate, is ultimately resolvable into 

 two prime factor — sun-warmth and air-warmth. The amount 

 of sun-warmth (assuming the sun's heat to be constant) depends 

 upon two things only — length of day, and quantity of suspended 

 matter and aqueous vapour in the air. The warmth of the air 

 depends upon contact with matter heated by the sun's rays and 

 upon the stoppage of radiation from the earth by aquei us vapour. 



