March 6, 1902] 



NATURE 



425 



by foods, Dr. Cotfield stated that in 1S71 he was called on to 

 inspect the house at which His Majesty (then Prince of Wales) 

 was supposed to have contracted typhoid fever, and reported 

 the results of his investigations in a letter which appeared in the 

 Times of January 22, 1872, in which he showed that, although 

 there were certain sanitary defects in the house in question, 

 there were no such defects as had been previously described. 

 For instance, it had been said that the water-closet in their 

 Royal Highnesses suite of apartments was directly connected 

 with a cesspool beneath them, and that its soil-pipe was not 

 ventilated. Neither of these statements was true ; there was 

 no cesspool under the water-closet at all, nor, indeed, anywhere 

 on the premises, and the soil-pipe was fully ventilated. There 

 was, in fact, nothing the matter with that water-closet, and it 

 is certain that His Royal Highness did not get his attack of fever 

 from any foul air in it. There was, however, a defect in a 

 water-closet in the middle of the house, and he was unable to 

 say positively that the outbreak of the disease was not due to 

 defective sanitary arrangements. On looking through his notes, 

 made some thirty years ago, he had come to the conclusion that, 

 although it was proved that the outbreak was not caused by 

 water or milk, it was in all probability caused by some other 

 food (such as oysters or salad) which was partaken of 

 by His Royal Highness, the other gentlemen of the party 

 and some of the menservants (among whom all the cases 

 occurred), perhaps at a shooting luncheon, but not by 

 the Princess of Wales, or by any of the other ladies 

 or female servants. Had the outbreak beeii caused by the 

 insanitary condition of the premises, it would certainly have 

 attacked some of those who were most in the house, whereas 

 it attacked those, who were most out of doors and some of those 

 who did not sleep in the house at all. 



He then described cases in which the disease had been dis- 

 tributed by means of sewer air and by the washing and mangling 

 of clothes. The questions of ground water and of direct infection 

 were also considered. An account was given of the behaviour 

 of the typhoid bacillus in various circumstances, and the lecture 

 concluded with a reference to the prevalence of typhoid fever in 

 South Africa and its probable dissemination by means of dust 

 and flies, as well as by water, and with some tables of statistics 

 showing the great diminution of the death-rate from the disease 

 in England and Wales, and also in Paris, daring recent years. 

 The increase of the disease in Paris during the years 1S99-1900 

 was not peculiar to that city, as it was shared by London and 

 England generally, and it was only heard of because the Paris 

 Exhibition was held in 1900. 



EVOLUTION AND ITS TEACHING.^ 

 pVER since the dawn of the human intellect, man has tried 

 to increase his knowledge in two ways, by observation and 

 by speculation. Observation came first, for that is common to 

 man and animals. Speculation is a distinctly human attribute, 

 and we find that it soon out-distanced observation, and formed 

 the basis of the earlier philosophies. But during the last few 

 centuries, the observational method has once more come to the 

 front under the name of science, and its conclusions have not 

 always been in accord with those of the speculative philosophies 

 which preceded it. 



The difference between the two methods is that whereas 

 speculation starts a chain of reasoning from one or two proposi- 

 tions which are taken as absolutely true, science reasons from 

 the basis of as large a number of observations as possible, and 

 tries to find a hypothesis which connects them all together ; 

 or explains them, as it is usually called. 



An Outline of Evolution. 

 The idea of evolution originated with the Greeks, but only as 

 a speculation, which led to nothing ; and its scientific history 

 may be said to C(jmmence in the early part of the last century, 

 when the practically new theory of the origin of species by 

 gradual development was proposed by Lamarck. This theory 

 was at first discredited for lack of evidence ; but it was developed 

 and demonstrated by Darwin in the middle of last century. 

 .\bout the same time it was pointed out by Lord Kelvin that 

 not only was the sun cooling, but that all kinds of energy, when 



1 Abridged from an inaugural address, delivered before the .\ustralasian 

 Association for the Advancement of Science, by Captain F. W. Hutton, 

 F.R .S., president, on January 8. 



converted into heat, lost a portion by radiation into space, and 

 that this process must go on until the whole universe was of a 

 uniform temperature. So that, although the amount of energy 

 in the universe remains unalterable, it will, by redistribution, 

 be brought into the potential state, and thus, when every pos- 

 sible action is counterbalanced by other actions, energy will 

 practically disappear. 



From this theory of "dissipation of energy" it follows that 

 as the earth is cooling, life cannot go on for ever ; and also that 

 at some former time the earth must have been too hot for the 

 existence of protoplasm. Consequently, life can only have a 

 limited existence on the earth. It must have had a beginning, 

 and must come to an end. 



But the inference extended further. Not only living beings, 

 but even the whole solar system must have had a beginning, 

 not indefinitely remote ; because most of its members still con- 

 tain a large amount of their original heat. And if the solar 

 system had a beginning, so also must each star in the heavens 

 have had a beginning ; for the very fact that we can see them is 

 a proof that they are radiating out energy. And, it was asked, 

 why should not the whole universe, visible and invisible, have 

 had a common origin and a common beginning in time ? This 

 had been the opinion of Immanuel Kant in the middle of the 

 eighteenth century, and although modern astronomy has not 

 altogether confirmed his speculations, it has proposed a hypo- 

 thesis which is not very dissimilar. This is the " meteoritic 

 hypothesis," and is chiefly the work of Sir Norman Lockyer 

 and Prof. G. H. Darwin. I will give you a short sketch of the 

 views held by the former.^ 



Inorganic Evolution. 



The close connection between the orbits of comets and those 

 of meteoritic streams has led to the universally admitted con- 

 clusion that comets are neither more nor less than swarms of 

 meteorites, .\gain, the resemblance between the spectra of 

 comets and those of nebuUx" suggests that these also are swarms, 

 or aggregations, of meteorites. And we naturally infer that the 

 stars with similar bright-line spectra must be collections of 

 meteorites. From bright-line stars we pass to those of which 

 the meteoritic origin is no longer to be recognised, all having 

 blended together. Further, it is claimed that by supposing vari- 

 able and temporary stars to be due to the meeting and entangle- 

 ment of two meteoritic swarms we get a better explanation of 

 the observed phenomena than any other hypothesis can give. 



This meteoritic hypothesis supposes that the present material 

 universe was at one time in a state of " cosmic dust,"' spread 

 irregularly through space, and moving slowly in many directions. 

 It is the original irregular distribution of the cosmic dust and its 

 irregular movements which are the source of all the energy in the 

 universe. We have specimens of this cosmic dust in the chon- 

 droi, or spherules, of which many of the stony meteorites are 

 built up. They are small round bodies of crystallised minerals, 

 varying from microscopic dimensions to the size of a marble. Of 

 course, these chondroi are not the first form in which matter 

 existed. They are evidently due to chemical reactions, and we 

 could frame several different hypotheses as to their origin and 

 history. But these would be speculations which could not, 

 at present, be verified, and so we must content ourselves with 

 the chondroi as the earliest form of matter known to us. 



Through the action of gravitation, much of the cosmic dust is 

 supposed to have aggregated into meteorites, the irregular move- 

 ments of which were, in certain places, reduced to order ; and so 

 arose a number of meteoritic streams, or swarms, moving through 

 space. Still, under the force of gravitation, each of these swarms 

 got more and more dense, until, at last, collisions took place 

 between the meteorites ; light and heat were given out, and the 

 swarm became a nebula. The heat produced by the collisions 

 would, at first, be slight, but would gradually increase, until the 

 whole of the solid material was resolved into vapour and a star 

 was formed. Concentration, however, would still go on, and 

 the temperature of the star would rise until, in time, the loss by 

 radiation more than counterbalanced the gain by concentration, 

 when the star would begin to cool. At last light would no longer 

 be given oft", and the star would end by becoming a dark cold 

 body moving in space. Of course, some stars would attain a 

 higher maximum temperature than others, and either a single'or 

 a douiile star might be the result of the condensation ; but all 

 would follow a somewhat similar development. 



1 See " The Meteoritic Hypothesis" (llacmillan, 1890) ; and " Inorqanic 

 Evolution ■■ (Macmillan, 1900J. 



NO. 1688, VOL. 65] 



