February 6, 1896] 



NATURE 



11^ 



frigerator. If the oxygen is replaced by air, no liquid jet can be 

 seen unless the pressure is raised to i8o atmos. If the carbon 

 dioxide is cooled by exhaustion (to about I in. pressure) or 

 - 115°, liquid air can easily be collected in the small vacuum 

 vessel D, or if the air pressure is raised above 200 atmos. , 

 keeping the cooling at - 79° as before. The chief dif- 

 ficulty is in collecting the liquid, owing to the rapid cur- 

 rent of gas. The amount of liquid in the gas jet is 

 small, and its collection is greatly facilitated by directing 

 the spray on to a part of the metallic tube above the little 

 hole, or by increasing resistance to the escaping gas by placing 

 some few turns of the tube, like B in the figure, in the upper 

 part of the vacuum tube, or generally by pushing in more tube 

 m any form. For better isolation, the pipe can be rolled between 

 two vacuum tubes, the outer one being about nine inches long 

 and one and a half inches diameter, as shown in Fig. 3 ; the 

 aperture in the metal pipe has a small piece of glass tube over 

 it, to help the collection of the liquid. Using this apparatus and 

 an air supply at 200 atmos. with no previous cooling, liquid air 

 begins to collect in about five minutes, but the liquid jet can be 

 seen in two to three minutes. In Fig. 4 the metallic tube in 

 the vacuum vessel is placed in horizontal rings, leaving a central 

 tube for the passage of the glass tube c, which is used to cool 

 bodies or examine gases under compression ; the inner lube can 

 be filled for an inch with liquid air at 60 atmos. pressure, in 

 about three minutes. A double coil of pipe may be advantage- 

 ously used in some experiments ; the efficiency is low, but it 

 affords a quick method of reaching low temperatures and 

 collecting a few hundred cubic centimetres of liquid air. By 

 the use of this apparatus air at the ordinary temperature can be 

 simply converted into liquid air at the boiling point, — 194°, in 

 less than ten minutes ; a fall of 200° is effected in this short 

 period of time. 



The author, after giving a sketch of the results up to the 

 present achieved in connection with the liquefaction of hydrogen, 

 remarks that hydrogen, cooled to - 194" {80° abs. /), the boiling 

 point of air, is still at a temperature which is two and a half 

 times its critical temperature, and its direct liquefaction at this 

 point would be comparable to that of air taken at 60°, and 

 liquefied by the apparatus just described. Now, air supplied at 

 such a high temperature greatly increases the difficulty and the 

 time required for liquefaction. Still, it can be done, even with 

 the air supply at 100°, in the course of seven minutes; and this is 

 the best proof that hydrogen, if placed under really analogous 

 conditions, at - 194° must also liquefy with the same form of 

 apparatus. Hydrogen, cooled to - 200°, was forced through a 

 fine nozzle under 140 atmos. pressure, and yet no liquid jet 

 could be seen. If the hydrogen contained a few per cent, of 

 oxygen the gas jet was visible, and the liquid collected, which 

 was chiefly oxygen, contained hydrogen in solution, the gas 

 given off for some time being explosive. 



If, however, hydrogen, previously cooled by a bath of boiling 

 air, is allowed to expand at 200 atmos. over a regenerative 

 coil similar to that shown in Fig. 2, but longer, a liquid jet can 

 be seen after the circulation has continued for a few minutes 

 along with a liquid which is in rapid rotation in the lower part 

 of the vacuum vessel. The liquid did not accumulate, owing to 

 its low specific gravity and the rapid current of gas. These 

 difficulties will doubtless be overcome by the use of a differently 

 shaped vacuum vessel and by better isolation. The liquid jet 

 can, however, be used as a cooling agent, like the spray of liquid 

 air obtained under similar circumstances, and, this being practic- 

 able, the only difficulty is one of expense. In order to test in 

 the first instance what the hydrogen jet could do in the pro- 

 duction of lower temperatures, liquid air and oxygen were placed 

 in the lower part of the vacuum tube just covering the jet. The 

 result was that in a few minutes about 50 c.c. of the respective 

 liquids were transformed into hard white solids resembling 

 avalanche snow, quite different in appearance from the jelly-like 

 mass of solid air got by the use of the air pump. The solid 

 oxygen had a pale, bluish colour, showing by reflection all the 

 absorption bands of the liquid. There is no reason, apart from 

 that of cost, why a spray of liquid hydrogen, at its boiling point 

 in an open vacuum vessel, should not be used as a cooling agent 

 in order to study the properties of matter at some 20° or 30 above 

 the absolute zero. 



The only widely distributed element which has not yet been 

 liquefied is fluorine ; and it would seem that, although the atomic 

 weight of fluorine is nineteen times that of hydrogen, it must in 

 he free state approach hydrogen in volatility. If the chemical 



NO. I 37 I, VOL 53] 



enei^y of fluorine is abolished at low temperatures, like that of 

 other active substances, some kind of glass or transparent sub- 

 stance, less brittle than calcium fluoride, could be employed in 

 the form of a tube, and the liquefaction of fluorine achieved by 

 the use of hydrogen as a cooling agent. 



SCIENCE IN THE MAGAZINES. 



"POLITICS saturates the February magazines, but science is 

 -*• not altogether drowned in this plethora of diplomatic 

 diatribes. There are four articles in the Contemporary of. 

 interest to scientific readers. Mr. Herbert Spencer traces the 

 development of the sculptor, and shows how, in its primitive 

 character, sculpture was an auxiliary to ancestor-worship. " The 

 tomb and the temple are," he shows, "developed out of the 

 shelter for the grave— rude and transitory at first, but eventually 

 becoming refined and permanent ; while the statue, which is 

 the nucleus of the temple, is an elaborated and finished 

 form of the original efligy placed on the grave. The im- 

 plication is that, as with the temple so with the statue, the 

 priest, when not himself the executant, as he is among savages, 

 remains always the director of the executant — the man whose 

 injunctions the sculptor carries out." Mr. W. H. Hudson 

 writes pleasantly, if somewhat aimlessly, about the village of 

 Selborne and of the simple naturalist whose observations have 

 made it famous. Mr. W. H. Mallock continues his study of 

 " Physics and Sociology." The argument of the two articles 

 which preceded the present one may be thus summarised : 

 Great men are analogous to atoms of superior size, on whose 

 presence the aggregation of all the other atoms depend, there- 

 fore they should form the first study of the sociologist. Two 

 propositions (among others) which follow from this conclusion 

 are now stated by Mr. Mallock ; the first of them being more or 

 less of a heresy, so far as scientific opinion is concerned. The 

 propositions are as follows, (i) Other things being equal, com- 

 munities progress and become civilised not in proportion to the 

 talents of the mass of the individuals who compose them, but in 

 proportion to the percentage which occurs in each of the indi- 

 viduals whose talents are superior to those of the mass. 

 (2) Other things being equal, communities progress and become 

 civilised in proportion to the desirability of the rewards which 

 are practically attainable in each by the exercise of superior 

 talents, and which thus stimulate the possessors of these talents 

 to develop them, and make them actual instead of merely 

 potential. Mr. D. C. Boulger having suffered from diphtheria, 

 and been made a victim of the anti-toxin treatment, survived, 

 and now records his experience of the disagreeable character 

 of the disease and its sequelae, all of which unpleasant- 

 ness was aggravated, in his opinion, by the employment 

 of antitoxic serum. From his particular case, he passes 

 to a general discussion of diphtheria and antitoxin, which 

 he condemns. So few are the gifts to science and education 

 in England, that we rejoice to find Mr. Bernard Shaw commend- 

 ing in the Contemporary such benefactions to the attention of 

 millionaires. The questions which a millionaire, moved by a 

 generous spirit to benefit any locality, should ask himself are : 

 " Has it a school, with scholarships for the endowment of 

 research, and the attraction of rising talent at the universities ? 

 Has it a library, or a museum ? If not, then he has an opening 

 at once for his ten thousand or hundred thousand pounds." 



" Reflex Action, Instinct, and Reason " are discussed from 

 the point of view of their development in the Fortnightly by 

 Mr. G. A. Reid. It suffices here to call attention to the 

 article, which is a chapter from a forthcoming book on " The 

 Present Evolution of Man," and to state the definitions of 

 instinct and reason given in it. Instinct is defined as *' the 

 faculty which is concerned in the conscious adaptation of means 

 to ends," by virtue of inborn inherited knowledge and ways of 

 thinking and acting. Reason is defined as " the faculty which 

 is concerned in the conscious adaptation of means to ends" by 

 virtue of acquired non-inherited knowledge and ways of thinking 

 and acting. An admirable article on " Plant Names" appears 

 in the Quarterly Review (January), being a review of the 

 " Index Kewensis" and of four other recent publications upon 

 the names of plants. In the National, Mr. Walter B. Harris 

 describes Tiflis, the capital of Transcaucasia, and in Scrihner 

 an interesting account is given of an ascent of Mount Ararat, 

 the paper being illustrated by several of the finest specimens of 

 process-work we have ever seen. 



