30+ 



NATURE 



[Feb. 14, 1878 



two formidable objections wliich he foresaw would be brought 

 against them, namely, the improbability of two bodies endowed 

 with enormous energy in the form of rapid motion coming 

 into actual collision with one another, and secondly, the 

 want of experience of like movements in the universe. It is 

 but seldom that a theory, however ingenious, can be upheld 

 against tzvo antecedent improbabilities, but granting Dr. CroU 

 all he asks, even to the existence of non-luminous bodies moving 

 through space with a velocity of 1,700 miles per second, there 

 may still be brought more serious objections than either of the 

 above. Our knowledge of the actual motions of the stars in 

 space has recently been greatly extended, and it is now well 

 known that proper motions exceeding thirty miles"per second are 

 very rare, and that probably there is no well-authenticated case 

 of a velocity greater than forty miles per second. It has long 

 since been ascertained also that the proper motion of our own 

 sun in space is at the rate of four miles per second only. It is, 

 of course, possible or fortunate that the two bodies from whose 

 collision the solar nebula originally derived its vast stores of 

 heat might be of such equal masses and velocities 'that the mo- 

 tion of translation should be so nearly destroyed, and the whole 

 converted into heat, but it is inconceivable that amid all the 

 diversity of dimensions of the heavenly bodies it should invari- 

 ably happen that the resultant movement of the combined masses 

 should ba reduced to such insignificant figures as the above. 



It is strange that it should not have occurred to Dr. CroU that 

 the heat generated by the impact of two bodies in such rapid 

 motion cannot be considered as remaining constant for nearly the 

 length of time he computes, because the rate of radiation from 

 so intensely heated a sun will be enormously greater than it is 

 now. Indeed the origin of the solar heat does not materially 

 affect the question at issue, which is rather of the means of con- 

 tinuous and equable supply than of the primary source. The 

 contraction theory of Helmholtz addresses itself to meet this 

 difficulty, but alone it is probably insufficient. In the Popular 

 Science Review of January, 1875, I have directed attention to 

 other possible and supplementary means of heat supply, which, 

 being continuous, will tend to prolong the period during which 

 the radiation of heat from the sun shall be nearly constant, and 

 hence favourable to the development of organic life. Without 

 advocating any peculiar views of my own which recent disco- 

 veries have necessarily somewhat modified, I content myself 

 with pointing out what appear to me to be grave difiiculties in 

 the way of accepting the theories and explanations of Dr. 

 CroU. John I. Plummer 



Nacton, Ipswich 



Faraday's "Experimental Researches" 



Doubtless many of your readers will have observed an 

 advertisement of a well-known antiquarian bookseller professing 

 to be able to supply "a perfect copy " of Faraday's "Experi- 

 mental Researches " at a price not too exorbitant for a complete 

 original copy of that priceless work. 



Any who may have applied for the work will, perhaps, share 

 with me the indignation with which they discover that the so- 

 called perfect copy is only such in virtue of being a ' ' facsimile re- 

 print " (sic) not twelve months old, though dated on the title-page 

 1839. But perhaps scientific men are too innocent of the ways 

 of antiquarian caterers to receive with calm contentment the 

 assurance that they have not been deceived. 



SiLVANUs P. Thompson 



University College, Bristol, February 5 



CLAUDE BERNARD 



T N rapid succession we are compelled to chronicle the 

 ■*• recent serious losses by death to French science. 

 To the names of Leverrier, Becquerel, and Regnault, we 

 regret to add that of the equally famous physiologist, 

 Prof. Claude Bernard, who died in Paris on the evening 

 of February 11. He was born at St. Julien, near Ville- 

 franche, in the Rhone department, July 12, 18 13. After 

 completing a course of study in the Paris faculty of 

 medicine he was appointed hospital-surgeon in 1839. 

 Two years later he became assistant to the well-known 

 physiologist, Prof. Magendie, in the College de France, 

 and continued in close connection with him for thirteen 

 years, during the last half of this time lecturing himself 

 as privat-docent. A series of notable discoveries made 



during this period caused his election, in 1854, to the 

 Academy of Sciences, and his appointment to the newly- 

 founded professorship of general physiology in the Col- 

 lege de France. This he exchanged in the following 

 year for the chair of experimental physiology, a position 

 which he occupied up to the time of his death. 



As an original investigator, Bernard stands among the 

 foremost of the century. He entered upon his career at 

 the epoch when Magendie, the chief founder of the 

 modern French school of physiology, had completely 

 altered the character of this study by the introduction of 

 a variety of experiments on living animals, such as the 

 action of the alkaloids, &c. Bernard entered with en- 

 thusiasm on the new field of experimental activity opened 

 up by his master, and by a swift succession of remarkable 

 discoveries v;ith regard to the changes taking place in the 

 humari organism, guided the young science into a com- 

 pletely new channel. Of these the most important were 

 connected with the phenomena of digestion, and espe- 

 cially the relation of the nerves to these processes. Per- 

 haps the most valuable was the exhaustive investigation 

 into the functions of the pancreatic juice (in 1850), in 

 which he showed that this fluid was the only one in the 

 digestive apparatus capable of so modifying fatty matter 

 that it can be absorbed by the chyle ducts, and that the 

 digestion of this portion of the nourishment introduced 

 into the system was its sole purpose in the animal 

 economy. Another discovery at this period, which 

 attracted universal attention, was that of the saccharine 

 formation in the liver. Bernard found that not only was 

 sugar a normal constituent of the liver, but that while the 

 blood, on entering into this organ, was completely free 

 from saccharine matter, large amounts of the latter could 

 be detected after it left the liver to pursue its way to the 

 heart. Interesting as this fact was, it was eclipsed by the 

 discovery of the two remarkable connections between 

 this function of the liver and the nervous system. 



It was ascertained, first that this normal formation of 

 sugar in the liver could be totally interrupted by severing 

 the pneumo-gastric nerve in the neighbourhood of the 

 heart ; and secondly, that by wounding a certain place on 

 the fourth ventricle of the brain, near the origin of the 

 eighth pair of nerves, it was possible to cause such an 

 abnormal formation of sugar that an animal within two 

 hours after such an operation showed all the symptoms 

 of diabetes. In recognition of these brilliant experiments 

 the physiological prizes of the French Academy were be- 

 stowed upon Bernard in 1851 and 1853. In a continuation 

 of this line of research in 1859 he made the important dis- 

 covery that the sugar for the embryo is prepared in the 

 placenta, and not in the liver. Shortly previous to this time 

 he published the results of extensive observations on the 

 temperature of the blood, in which he showed that 

 remarkable alterations in the degree of warmth take place 

 on the passage of the blood from one organ to another, 

 especially in the different parts of the digestive and 

 respiratory systems. The absorption of oxygen by the 

 blood formed the subject of a memoir in 1858, from which 

 it appears that the coefficient of absorption diminishes 

 gradually with an increase of temperature, and becomes 

 zero at 38° — 40" C. in the case of mammals, and 40° — 44" 

 C. in the case of birds, viz., at the temperatures at which 

 death sets in. The respective amounts of oxygen in the 

 arterial blood, and red and black venous blood were like- 

 wise carefully estimated, and the chemical causes for the 

 differences in colour revealed. Among the other leading 

 researches of Bernard must be mentioned those on the 

 comparative properties of the opium alkaloids ; on the 

 poisonous properties of curarine ; on the sympathetic 

 nerves in general ; as well as numerous investigations 

 on the individual processes in the act of digestion. 

 Many of these discoveries, as well as the results deduced 

 from them, have formed subjects for long-continued 

 controversies. With rare exceptions, however, not only 



