82 



KNOWLEDGE. 



[April 2, 1894. 



life much better than ours ; tbey showed a greater capacity 

 for adapting themselves to the new conditions, although 

 in this respect they fell short of our sailors ; they were 

 more provident in proceeding at once to make good 

 roads from their landing-place to the front ; they were 

 conspicuously better cooks, and it is even said that they 

 feasted upon what our men threw away. Once more, 

 I cannot do better than quote Mr. Radcliffe's words. 

 " Yet there was still another tragedy to be enacted in 

 the Crimea before the war ceased. I have already 

 spoken of the French army as suffering less than the 

 British from the sicknesses incident to the campaign 

 during the winter of 1854-55, and I have more than once 

 referred to the better organization of our allies, in view 

 of field service, at the beginning of the war. There can 

 be little doubt that to this better organization, and to the 

 greater adaptability for campaigning displayed by the 

 French soldier during the first period of the war, the 

 comparative immunity of our allies from the sufferings 

 which crippled the British forces was owing. But after 

 the termination of the first winter, and during the time 

 that the British army was recovering from the state into 

 which it had been plunged, and was proceeding step by 

 step to that extraordinary pitch of health and efficiency I 

 have described, the strange spectacle was presented of the 

 French army gradually sinking into a state of misery and 

 disease, which eventually, in the winter of 1855-5G, 

 equalled, and indeed, if it were possible, surpassed what 

 had been witnessed in the British army the preceding 

 winter. A more startling contrast was never contem- 

 plated than that presented by the English and French 

 camps and the English and French hospitals during the 

 winter of 1855-56. On the one side — the French — was to 

 be seen a gallant army melting rapidly away from 

 privations and from typhus, dysentery, scurvy, camp- 

 diarrhoea, and other deadly ailments ; camps degenerated 

 to the lowest depths of negligence and filth ; hospitals from 

 which all semblance of hospital care and order had gone, 

 and which were equally deadly to patients and attendants.- 

 As in the Crimea, so in the Bosphorus ; the scenes which 

 had been enacted in the British hospitals at Scutari in the 

 winter of 1854-55 were now re-enacted in the French 

 hospitals in Constantinople in the winter of 1855-56. 

 But there the resemblance ended. With the coming of 

 the spring of 1856 there was no arrest of the diseases 

 which were sapping the marrow of the French army, such 

 as there had been in the case of the British army the 

 preceding year ; and when peace was declared, the entire 

 disablement of the French forces from privations and 

 sickness appeared to be imminent." 



Towards the close of the siege the Russians suffered 

 also very severely from typhus, and when the army after 

 the conclusion of the war was distributed over the country, 

 it carried the fell plague with it to every halting-place, 

 causing a wide-spread mortality among the civilian 

 population, which probably far exceeded one hundred 

 thousand. 



Incidentally, a lesson in pathology (the science which 

 treats of the nature of disease) of lasting importance was 

 finally driven home by this campaign. Hitherto the 

 French doctors, who at that time held a very high position 

 in the scientific world, had been destitute of experience 

 of typhus fever, and combated the views of Jenner, 

 Murchison and Budd that ' continued fever ' comprised 

 at least two diseases which were fundamentally distinct, 

 alike in symptoms, causes, and mode of propagation. The 

 French army surgeons had ample opportunities on the 

 plateau before Sebastopol of seeing the behaviour of the two 

 diseases side by side, and from that time there was no 



disagreement as to the distinctness of typhus, which is 

 invariably associated with overcrowding and is propagated 

 directly from man to man, from typhoid or enteric fever, 

 which is associated with conditions of exeremental filth 

 and propagated for the most part indirectly by means of 

 polluted water or milk. 



True sanitary method necessitates a foundation of 

 exact knowledge of the nature of disease. 



Mr. Radcliffe adds with great force : " If it had been 

 possible for any doubt to have rested upon this great result 

 and its causes, the spectacle of the French army sinking 

 into the slough out of which we had escaped, and the 

 conditions under which this happened, would have put an 

 end to it. Here, then, was a lesson in hygiene, having 

 the precision and force of a scientific experiment, as 

 applicable to civil as to military life, and which exercised 

 a less obvious tut hardly less important part on the 

 progress of civil hygiene in this country than it did upon 

 military hygiene." 



THE THERMAL RADIATION FROM SUNSPOTS. 



By W. E. Wilson, M.R.I.A. 

 CoinmunicKfi'd to the Royal Society, January -itli, 1894.. 



THESE observations were made by means of a large 

 heliostat, lent by the Royal Society, and a Boys' 

 radio-micrometer. The heliostat consists of a 

 plane silver on glass mirror of 15 in. aperture. It is 

 mounted equatorially, and driven by a clock. When 

 in use, it is adjusted to reflect the sunlight to the north 

 pole, and as long as the driving clock is kept in motion the 

 beam of light remains fixed in that position. In the track 

 of this beam, and about 12 ft. from the plane mirror, is 

 mounted a concave silver on glass mirror of 9 in. aperture, 

 and about 18 ft. focus. Its axis points to the south pole, 

 so that the cone of rays formed by it strikes the centre of 

 the plane mirror at a short distance inside the focus. A 

 small plane mirror mounted on the end of an arm is then 

 so placed as to intercept the cone of rays, and reflect it 

 horizontally into the observatory window ; an achromatic 

 lens enlarges the solar image which is formed on a screen 

 in the room to 4 ft. in diameter. 



Behind this screen, and standing on a pier of concrete, 

 is mounted the radio-micrometer. The aperture through 

 which radiant heat reaches the sensitive thermo-couple is 

 a round hole drilled through a thick sheet of brass, and is 

 only 1 mm. in diameter. A white cardboard screen is 

 placed in front of the brass one to cut off heat from falling 

 on the latter, and is provided with a hole slightly larger. 

 A beam of lime-light is thrown on the mirror of the radio- 

 micrometer, and reflected on to the scale in the usual way. 

 The diagonal mirror of the heliostat is provided with slow 

 motions in two directions, which are moved by long rods 

 and hook joints inside the observatory. Thus any part of 

 the sun's disc can be placed on the small aperture of the 

 radio-micrometer, and the driving clock will then keep it 

 there. 



The observations are taken in the following manner. 

 A small screen is placed over the aperture of the radio- 

 micrometer, and the zero position of the spot of light on 

 the scale noted. The screen is then removed, and the 

 umbra of a sunspot placed on the aperture. The reading 

 is then taken and entered in column u. The image is 

 then moved, so that a part in the neighbourhood of the 

 spot, but at thf same distance from the centre of the solar disc, 

 is placed on the aperture. This reading is entered m 

 column N. Finally, a reading is taken at the centre of 



