December i6, 1897 J 



NA TURE 



165 



Society, viz. before the Chicago Section (April 24, 1897) : 

 Quaternions as members of four-dimensional space, by Prof. 

 A. S. Hathaway. Note on the invariants of n points, by Dr. 

 E. O. Lovett, is another communication which was made at the 

 same meeting. — Dr. Lovett contributes also a note on the 

 fundamental theorems of Lie's theory of Continuous Groups 

 (October 30). The object of the note is to call attention to a 

 misapprehension, if not an error, in a paper, by J. E. Campbell, 

 on a law of combination of operators bearing on the theory of 

 continuous transformation groups, read at the March II meet- 

 ing of the London Mathematical Society {Proc, vol. xxviii. 

 pp. 381-390). The fourth paper is one read at the Toronto 

 meeting, August 16. It is an interesting short note by Prof. T. 

 F Holgate, and is entitled, "A geometrical locus connected 

 with a system of coaxial circles." The writer's object is to find 

 the locus of points through which three lines can be drawn 

 tangential to three circles of a coaxial system in pairs. — Con- 

 dition that the line common to w - i planes in an n space may 

 pierce a given quadric surface in the same space, by Dr. V. 

 Snyder, was read at the Detroit meeting mentioned above. The 

 note is a generalisation of a proof recently given by the author 

 (criteria for nodes in Dupiti's cyclides) of the geometric signifi- 

 cance of a certain determinant. — Dr. E. W. Brown gives a 

 valuable analysis of Prof. H. Lamb's Hydrodynamics. Of this 

 the reviewer writes : "' The author is to be congratulated on the 

 completion of a task which will earn him the gratitude of all 

 those who are now, or may in the future be, interested in Hydro- 

 dynamics. — In the Notesare particulars of the British Association 

 meeting at Toronto, in so far as it concerned mathematicians. 

 — Other matters are a list of the mathematical courses for the 

 winter semester (1897-98) in the Universities of Gottingen, 

 Leipzig, Munich, Vienna and Strassburg. 



Ix the Meteorologische Zeitschrift for November, Dr. J. Hann 

 gives the daily ranjje of the meteorological elements at Cairo, 

 deduced from the observations of the five years 1891-5, as pub- 

 lished in the Khtimc Meiisuel of the observatory at Abbassieh. 

 These values are of some interest, as Dr. Hann states that the 

 monthly means contained in the tables give for the first time the 

 true daily means for Cairo. The barometric range exhibits the 

 small amplitudes for the latitude that have been noticed in 

 other parts of the Mediterranean. The night minimum does 

 not appear to fall below the daily mean throughout the year. 

 The range of temperature shows no special peculiarities ; it is 

 greatest in June, and is greater in the dry spring than in the 

 damp autumn. The daily range of wind force is noteworthy, 

 especially during spring and autumn ; during the year there is 

 only a very slight variation at night-time, but in the after- 

 noon there is a great increase in the force from winter to spring, 

 and from summer to autumn. During the winter half-year the 

 nights are clear, while cloud prevails at the middle part of the 

 day ; in the summer the morning hours are cloudiest, but from 

 about noon the sky is almost cloudless. The influence of the 

 overflow of the Nile in the autumn naturally affects the range of 

 humidity. 



In \he Journal of Botany for November and December, Mr. 

 F. Townsend completes his monograph of the British forms of 

 ^«//zra.f/rt, of which he makes fourteen "species" founded on 

 von Wettstein's monograph of the genus. It is accompanied 

 by seven plates illustrating the habit of each "species," and 

 details of the form of the flow-ers and leaves. — In a paper on 

 "New and Critical Marine Algse," Mr. E. A. L. Batters 

 describes a number of species new to science, together with a 

 new genus, of Floridece, Porphyrodiscus, from Berwick, with the 

 crustaceous habit of Hildenbrandtia. 



SOCIETIES AND ACADEMIES. 

 London. 

 Royal Society, November 25. — "On certain Media for 

 the Cultivation of the Bacillus of Tubercle." ^ By Dr. Arthur 

 Ransome, F. R.S. 



The following conclusions had been drawn from previous 

 experiments : — 



(i) That finely divided tuberculous matter, such as pure 

 cultures of the bacillus, or tuberculous matter derived from 



1 By permission of the Royal College of Physicians, this research, which 

 forms a portion of the Weber-Parkes prize essay, is communicated to the 

 Royal Society before publication. The cost of the inquiry is defrayed by 

 the Thrustan prize, presented to the author this year by Gonville and Caius 

 College, Cambridge. 



NO. 1468, VOL. 57] 



sputum, in daylight and in free currents of air is rapidly deprived 

 of virulence ; 



(2) That even in the dark, although the action is retarded, 

 fresh air has still some disinfecting influence ; and 



(3) That in the absence of air. or in confined air, the bacillus 

 retains its power for long periods of time. 



These observations afforded an explanation of the immunity 

 of certain places, and the danger of infection in others. They 

 show that where tuberculous sputum is exposed to sufficient 

 light and air, to deprive it of virulence before it can be dried up 

 and powdered into dust, no danger of infection need be dreaded. 

 It would appear further, from this research and others, that it is 

 only when there is sufficient organic material in the air, derived 

 from impure ground air, or from the reek of human bodies, that 

 the tubercle bacillus can retain its existence and its virulent 

 power. 



But, in addition to the above-mentioned researches, it seemed 

 desirable that an attempt should be made to ascertain what part 

 was played respectively by the several forms of organic impurity 

 that are present in insanitary dwellings. It was determined, 

 therefore, to collect the aqueous vapours arising from the ground, 

 or from human bodies, and to submit these products to the test 

 of trying whether they would serve as cultivating media for the 

 bacillus of tubercle. 



By means of a simple freezing mixture of ice and salt it was 

 easy to condense the aqueous vapour, both of the breath and 

 that coming from ground air. 



Some evidence was obtained with simple glycerine agar that 

 the organic fluids facilitated cultivation to some extent. With 

 the organic fluids there were only two failures, and growth was 

 fairly rapid. 



In the next series of trials, it was decided to use as the materia? 

 bases some non-nitrogenous substance, and at length it was^. 

 determined to use a particularly pure " filter-paper." 



Some degree of success was attained in twelve out of fifteeit- 

 specimens of the organic fluids. 



The degree of growth was also much the same as in the previous- 

 series, though perhaps slightly less vigorous. 



It was now determined to try to do without the help of the 

 glycerine, which, as is well known, so greatly assists the ordinary 

 cultivations of the bacillus. Accordingly, four tubes with simple 

 filter-paper as the supporting medium, and condensed fluid^^, from 

 the breath of a healthy person, and from that of a phthisical 

 patient, as nutrient fluids, were inoculated, and no glycerine was 

 added. In these tubes the same cultivation was used as in the 

 previous experiments. 



Shortly afterwards, two similar tubes with fluid from healthy 

 breath alone, but with 5 per cent, of glycerine, were sown with 

 the same cultivation, and were left at the ordinary temperature 

 of the laboratory, about 21° C. 



AH of the former group took on active growth within four 

 weeks, and one of the latter. In other words, it was proved 

 that pure filter-paper, moistened with these condensed fluids, 

 alone would suffice to nourish and promote the growth of the 

 bacillus, and, further, that this growth would take place at 

 ordinary temperatures. It may hence be concluded that wheir- 

 this organic fluid is present in ordinary dwellings, the bacillus- 

 may grow at the temperature of living rooms as well as at the^ 

 temperature of 35^ C. 



Two sets of tubes were then prepared of condensed vapour 

 from breath, and from ground air from a pure sandy soil. No 

 glycerine was added ; but for the solid medium, in some in- 

 stances, the pure filter-paper was employed ; in others, an or- 

 dinary lining paper, containing a little size, but carefully steri- 

 lised, was used. 



Some of these were placed in the incubator at a temperature 

 of 37° C., others were left in the dark at the ordinary tempera- 

 ture of the laboratory. 



In many of the tubes a free growth was observed as early as 

 the end of the first fortnight. 



Out of the total number in this series of 37, in thirty six in- 

 stances there was free growth on the medium employed, on both 

 kinds of paper, and all kinds of condensed fluid. Eleven of 

 them were grown at a temperature of about 20° C. In only one 

 instance was there complete failure (vapour from healthy 

 breath). 



The bearing of these researches upon the subject of the pro- 

 phylaxis against tuberculosis seems to be of some importance. 



They prove that any one of the various organically charged 

 vapours, whether coming from healthy or from diseased lungs, 



