JUNE 15. 1893J 



NA TURE 



161 



registering apparatus, which were exWbited recen'ly at the an- 

 niversary meeting of the Socu'te de Physique, and will be sent 

 up very shortly with a 113 cm. balloon inflated with pure 

 hydrogen. So a new departure may be said to have been 

 taken for the scientific exploration of the air at an altitude 

 where no human being can penetrate. The series of prizes 

 proposed by M. Hodgkins for 1893 and 1894, and the creation 

 of the Hodgkins medal by the Smithsonian Institution, certainly 

 add new interest to these experiments. 



M. Janssen intends to establish an apparatus for making pure 

 hydrogen in the Meudon Observatory in order to help M. Hermite 

 to send his sounding balloons to a higher level if possible. He 

 will, moreover, try to measure by direct observation the altitude 

 of the balloons sent, as long as they remiin visible from his 

 Observatory. 



This last scheme was adopted by Le Verrier, who says in 

 the Bulletin de l' Association Scientifiijiie de France for October 

 1874 : " La hauteur du ballon est toujours deduite de U mesure 

 du barometre et du thermometre, au moyen d'hypotheses 

 sur la repartition de la pression atmospherique. li s'agit 

 d'ecarter ces causes d'incertitude, et de me-;urer directement par 

 des operations trigonometriques la hauteur meme du billon ; 

 ce qui permettra de verifier les lois admises ou de les modifier. 

 l,es operations trigonometriques a terre seront faites par les 

 astronoms de I'observatoire sur le charge de cette partie des 

 depenses. La direction de I'aerostat fourni par I'observatoire 

 est confiee a M. W. de Fonvielle." The protracted illness of 

 (he illustrious astronomer and his subsequent death, prevented 

 the series of ascents from being tried as contemplated. 



The experiments already tried by M. Hermite, namely, on 

 March 3, prove that the balloon will remain long visible 

 from an Observatory, if the ascent is executed on a clear and 

 calm day with a considerable ascending force, which gold- 

 beater's skin can support without being torn by the friction. 



The ascent of March 21, when ordinary gas was employed, 

 took place with such velocity that the balloon was seen always 

 Hearing the zenith, independently of the diverging direct'on of 

 the air, the mean recorded velocity having been eight metres per 

 second from the time of starting to the time of maximum, 

 which was reached in three-quarters of an hour, according to 

 the automatic barometer. 



The inflating pipe (afipendice) which the balloon carried with 

 it, was 30 cm. diameter and 90 cm. long, and air took the place 

 vacated by the retreating gas, when the balloon descended. 

 Consequently it was found quite full when discovered, just the 

 same as when the balloon was liberated. Ttie only differenec 

 was that the gas had been expelled and replaced by air. 



Since the volume of the balloon remained quite constant 

 during the whole of the operation, it would have been quite easy 

 to determine the absolute distance from the observatory by 

 measuring the apparent diameter with a micrometer. By taking 

 simultaneously a reading of zenith distance and azimuth, it 

 would have been quite easy, by a series of observations con- 

 ducted from a single station, to ascertain the altitude of the 

 balloon and every circumstance of its motion. 



The principal object of M. Janssen will be to determine the 

 absolute minimum of temperature at the maximum altitude, 

 which can be done more or less precisely, and the direction 

 orvilocity of the winds blowing at difl'erent altitudes. Then 

 the indications of the registering instruments can be submitted 

 10 the rational control which is necessary before coming to any 

 definite conclusion. 



It is interesting to notice that these preliminary results are 

 inonformity withtheJouleandClausiustheory, whichasserts that 

 celestial space is at the temperature of - 273° C, or even 

 with the opinion that there is no limit to the refrigeration, as 

 asserted by other natural philosophers. 



Another question is raised by these experiments, when coupled 

 with Dewar's and Cailletet's discoveries relating t) the lique- 

 faction or solidification of the elements of the air. If the tem- 

 perature descends to such a degree it is necessary to admit that 

 the air loses its gaseous condition and becomes changed into a 

 series of minute crystals or drops, which follow the earth in its 

 motion through space, and are constantly vapourised when fall- 

 ing in regions where the temperature is somewhat above their 

 point of liquefaction or evaporation. 



Such are some of the questions raised by this new exploration 

 of elevated regions, rendered very easy by the unexpected facilicy 

 with which balloons and instruments in working order are re- 

 j.overed. This has been rendered |)ossible in France by the 



NO. 1233. VOL. 4S] 



interest taken in the matter by public schoolmasters, who have 

 been notified of the experiments by the newspapers, and 

 have found special instructions printed on a paper pasted to the 

 basket. It is certain that similar results may be obtained in 

 every civilised country in the world, and we trust this new 

 method will develop and improve so that unquestionable facts 

 will be discovered with regard to the mysterious cosmical fron- 

 tiers of our globe. W. de Fonvielle. 



DISINFECTANTS AND MICRO-ORGANISMS. 



CO.ME important results have recently been obained 

 ^ by Heider, who has been experimenting with dis- 

 infectants at higher temperatures and testing the effect pro- 

 duced u;)on their bactericidal properties. The author's first 

 contributions in this direction were published in 1891. 

 In Heider's original communication, " Ueber die Wirksamkeit 

 von Desinfektionsmittein bei hoherer Temperatur " (0»/ra/- 

 blatt fiir Backteriologie, vol. ix. 1891, p. 221), 

 temperatures of 55° and 75° C. were employed, and the 

 spjres of anthrax were selected for investigation. Although 

 these spores, it was ascertained, survived an immersion 

 during 36 days in a S per cent, solution of carbolic acid 

 ke,)t at the ordiniry temperature of the room, they were 

 destroyed in from one to two hours in a similar solution at 

 55°C. Weaker solutions of this acid {l percent, and 3 per 

 cent.), even when maintained at the higher temperature for 

 seven and eight hours, produced no effect upon the anthrax 

 spores. On the temperature being raised to 75° C, however, 

 three minutes' exposure to a 5 per cent, solution of carbolic 

 acid, fifteen minutes to a 3 per cent, solution, from two to two 

 and a half hours to a i per cent, solution sufficed to annihilate 

 these spores. Other materials were also investigated at these 

 high temperatures, and equally satisfactory results obtained. 

 Heider has brought together all his researches on this interest- 

 ing subject in an elaborat-; memoir, " Ueber die Wirksamkeit 

 der Desinfectionsmittel bei erhohter Temperatur," which has 

 been published in the Archiv.fiir Hygiene, vol. xv. p. 341. It 

 is pointed out how great an effect upon the powers of resistance 

 possessed by micro organisms may be exercised by the nature 

 of their surroundings, and that it may be taken that they are, 

 as a rule, more refractory in their normal environment than 

 when purposely introduced into various materials. This 

 has been shown by Yersin, in respect to the tubercle bacillus, 

 which succumbs more readily to certain temperatures when 

 exposed in artificial cultures than in sputum. Heider also found 

 that particular culture media had a remarkable effect in this 

 respect upon bacteria, that, for example, those grown in sugar 

 broth (3 per cent, cane sugar) proved far more capable of re- 

 sisting exposure to a high temperature than those introduced 

 into ordinary broth. In conclusion, it having been distinctly 

 proved that the bactericidal action of the majority of disin- 

 fecting materials is markediv increased when they are employed 

 at a higher temperature, the author recommends that in all 

 those cases where the destruction of spores is required, instead 

 of applying these materials in cold solutions, they should be 

 employed hot, or even boiling. The advantages derived by so 

 doing are not alone the greater security obtained and saving of 

 time, but economy in the cost of material, inasmuch as effectual 

 sterilisation may be accomplished by the use of le^s concentrated 

 solutions. 



THE NEW FLORA AND THE OLD IN 

 AUSTRALIA. 

 A VERY interesting paper on the effect which settlement in 

 ■^ Australia has produced upon indigenous vegetation, by 

 Mr. A. G. Hamilton, appears in the new number (vol. xxvi. ^ of 

 the "Journal and Proceedings of the Royal Society of New 

 South Wales." Mr. Hamilton traces with great care the 

 results which have sprung from the direct action of 

 man. He then deals with the alteration of the flora by the 

 introduction of a new fauna, and the modification of it by the 

 destruction of the native fauna. Finally, he considers the 

 introduction of a new flora, and the conseq lent modification o( 

 the indigenous flora through competition. 



The following is the portion of the paper relating to the 

 effects due to a new flora : — 



