252 



NA rURE 



\ya7i. 27, 1876 



the present century, made about thirty-six ascents of the 

 peak, for the purpose of making barometric observations. 

 In 1854 a society at Bagn^res founded on the Col de 

 Sencours, 511 feet below the Pic, on a hill immediately 

 above the Lake Oncet, a hotel for tourists. It is this 

 hotel which the Ramond Society has used as a temporary 

 observatory, until the Government provide the means of 

 erecting a proper building on the summit of the Pic. On 

 August I, 1873, the Commission appointed by the Society 

 provided a tolerably complete set of meteorological appa- 

 ratus on the Col de Sencours. Regular observations 

 were carried on till October 10, when want of funds cut 

 them short. On June i of the following year an observer, 

 along with the President of the Commission, General de 

 Nansouty, installed themselves and remained till Decem- 

 ber 25, when, as we recorded at the time, the severity of 

 the winter, for which they were insufficiently provided, 

 compelled them to beat a precipitate retreat. On June i 

 last year. General de Nansouty and M. Baylac again 

 established themselves in the temporary observatory, and 

 it is to be hoped they will be able to remain throughout 

 the whole of the winter. An avalanche did considerable 

 damage to the meteorological hut, and injured several of 

 the instruments ; fortunately, however, the observers 

 managed to repair most of the damage done. The in- 

 struments which have been provided are of the best kind, 

 and already observations of great value have been made, 

 some of which have been published by the Ramond Society. 



.This Society determined to accomphsh the erection of 

 a proper observatory on the Pic du Midi itself, and has 

 appealed to every quarter from which funds are likely to 

 be obtained. The work of construction has already been 

 begun. The building will be composed of three parts. 

 The dwelling-hous^, situated seven metres below the sum- 

 mit, is in part subterranean, and will open only on the 

 south side. It communicates by a tunnel with a circular 

 vaulted erection, which will contain the barometer, the 

 magnetic apparatus, &c. At a little distance will be 

 solidly built the Montsouris hut, intended to cover the 

 instruments which must be subjected to the direct influ- 

 ence of the atmosphere. 



The work is thus in progress, and there is every reason 

 to believe that it will soon be successfully completed, and 

 the station become one of the most important physical 

 observatories, not only in France, but on the globe. 



PROF. TYNDALL ON GERMS* 



THE author refers in an introduction to an inquiry on 

 the decomposition of vapours and the formation of 

 actinic clouds by light, whereby he was led to experiment 

 on the floating matter of the air. He refers to the ex- 

 periments of Schwann, Schroder and Dusch, Schroder 

 himself, to those of the illustrious French chemist Pas- 

 teur, to the reasoning of Lister and its experimental 

 verification, regarding the filtering power of the lungs ; 

 from all of which he concluded, six years ago, that the 

 power of developing life by the air, and its power of scat- 

 tering light, would be found to go hand in hand. He 

 thought the simple expedient of examining by means of a 

 beam of light, while the eye was kept sensitive by dark- 

 ness, the character of the medium in which their experi- 

 ments were conducted, could not fail to be useful to 

 workers in this field. But the method has not been much 

 turned to account, and this year he thought it worth while 

 to devote some time to the more complete demonstration 

 of its utility. 



He also wished to free his mind, and if possible the 

 minds of others, from the uncertainty and confusion which 

 now beset the doctrine of " spontaneous generation." 

 Pasteur has pronounced it "a chimera," and expressed 



* On the Optical Deportment of the Atmosphere in reference to the Phe- 

 nomena of Putrefaction and Infection. Abstract of a paper read before 

 the Royal Society, January 13th, by Prof. Tyndall, F.R.S. (Communicated 

 by the author.) 



the undoubting conviction that this being so it is possible 

 to remove parasitic diseases from the earth. To the 

 medical profession, therefore, and through them to human- 

 ity at large, this question is one of the last importance. 

 But the state of medical opinion regarding it is not satis- 

 factory. In a recent number of the British Medical 

 Journal, and in answer to the question, " In what way is 

 contagium generated and communicated?" Messrs. Braid- 

 wood and Vacher reply that notwithstanding " an almost 

 incalculable amount of patient labour, the actual results 

 obtained, especially as regards the manner of generation of 

 contagium, have been most disappointing. Observers are 

 even yet at variance whether these minute particles, whose 

 discovery we have just noticed, and other disease germs, are 

 always produced from like bodies previously existing, or 

 whether they do not, under certain favourable conditions, 

 spring into existence de novoP 



With a view to the possible diminution of the uncer- 

 tainty thus described, the author submits without further 

 preface to the Royal Society, and especially to those who 

 study the etiology of disease, a description of the mode 

 of procedure followed in this inquiry, and the results to 

 which it has led. 



A number of chambers, or cases, were constructed, 

 each with a glass front, its top, bottom, back and 

 sides being of wood. At the back is a Hitle door which 

 opens and closes on hinges, while into the sides are in- 

 serted two panes of glass, facing each other. The top is 

 perforated in the middle by a hole 2 inches in diameter, 

 closed air-tight by a sheet of india-rubber. This sheet is 

 pierced in the^middle by a pin, and through the pin-hole 

 is passed the shank of a long pipette ending above in a 

 small funnel. A circular tin collar 2 inches in diameter 

 and i^ inch high, surrounds the pipette, the space between 

 both being packed with cotton-wool moistened by glycer- 

 ine. Thus the pipette, in moving up and down, is not 

 only firmly clasped by the india-rubber, but it also passes 

 through a stuffing box of sticky cotton-wool. The width 

 of the aperture closed by the india-rubber secures the 

 free lateral play of the lower end of the pipette. Into 

 two other smaller apertures in the top of the case are 

 inserted, air-tight, the open ends of two narrow tubes, 

 intended to connect the interior space with the atmosphere. 

 The tubes are bent several times up and down, so as to 

 intercept and retain the particles carried by such feeble 

 currents as changes of temperature might cause to set in 

 between the outer and the inner air. 



The bottom of the box is pierced with two rows, some- 

 times with a single row of apertures, in which are fixed 

 air- tight, large test-tubes, intended to contain the liquid to 

 be exposed to the action of the moteless air. 



On Sept. 10 the first case of this kind was closed. The 

 passage of a concentrated beam across it through its two 

 side windows then showed the air within it to be laden 

 with floating matter. On the 13th it was again examined. 

 Before the beam entered, and after it quitted the case, its 

 track was vivid in the air, but within the case it vanished. 

 Three days of quiet sufficed to cause all the floating 

 matter to be deposited on the sides and bottom, where it 

 was retained by a coating of glycerine, with which the 

 interior surface of the case had been purposely varnished. 

 The test-tubes were then filled through the pipette, boiled 

 for five minutes in a bath of brine or oil, and abandoned 

 to the action of the moteless air. During ebullition aque- 

 ous vapour rose from the liquid into the chamber, where 

 it was for the most part condensed, the uncondensed por- 

 tion escaping, at a low temperature, through the bent 

 tubes at the top. Before the brine was removed little 

 stoppers of cotton- wool were inserted in the bent tubes, 

 lest the entrance of the air into the cooling chamber 

 should at first be forcible enough to carry motes along 

 with it. As soon, however, as the ambient temperature 

 was assumed by the air within the case, the cotton-wool 

 stoppers were removed. 



