424 



NA TURE 



SjSept. I, 1885 



bitten by rabid animals, who, if they had not been subjected to 

 this treatment would have died of that disease. The value of 

 his discovery is, however, greater than can be estimated by its 

 present utility, for it shows that it may be possible to avert other 

 diseases besides hydrophobia by the adoption of a somewhat 

 similar method of investigation and of treatment. This, though 

 the last, is certainly not the least of the debts which humanity 

 owes to the great French experimentalist. Here it might seem 

 as if we had outstepped the boundaries of chemistry, and have 

 to do with phenomena purely vital. But recent research indi- 

 cates that this is not the case, and points to the conclusion that 

 the microscopist must again give way to the chemist, and that it 

 is by chemical rather than by biological investigation that the 

 causes of diseases will be difcovered, and the power of removing 

 them obtained. For we learn that the symptoms of infective 

 diseases are no more due to the microbes which constitute the 

 infection than alcoholic intoxication is produced by the yeast-cell, 

 but that these symptoms are due to the presence of definite 

 chemical compounds, the result of the life of these microscopic 

 organisms. So it is to ihe action of these poisonous substances 

 formed during the life of the organism, rather than to that of 

 the organism itself, that the special characteristics of the disease 

 are to be traced ; for it has been shown that the disease can 

 be communicated by such poisons in entire absence of living 

 organisms. 



If I have thus far dwelt on the progress made in certain 

 branches of pure science it is not because I undervalue the other 

 methods by which the advancement of science is accomplished, 

 viz. that of the application and of the diffusion of a. knowledge 

 of Nature, .but rather because the British Association has 

 always held, and wisely held, that original investigation lies at 

 the root of all application, so that to foster its growth and 

 encourage its development has for more than fifty years been our 

 chief aim and wish. 



Had time peroiiited I should have wished to have illustrated 

 this dependence of industrial success upon original investigation, 

 and to have pointed out the prodigious ^trides which chemical 

 industry in this country has made during the fifty years of Her 

 Majesty's reign. As it is I must be content to remind you how 

 much our modern life, both in its artistic and useful aspects, 

 owes to chemistry, and, therefore, how essential a knowledge of 

 the principles of the science is to all who have the industrial 

 progiess of the country at heart. 



This leads me to refer to what has been accomplished in this 

 country of ours towards the diffusion of scientific knowledge 

 amongst the people during the Victorian era. It is true that 

 the English people do not possess, as yet, that appreciation of 

 the value of science so charactei istic of some other nations. Up 

 to very recent years our educational system, handed down to us 

 from the Middle Ages, has systematically ignored science, and 

 we are only just beginning, thanks in a great degree to the pre- 

 vision of the late Prince Consort, to give it a place, and that but 

 an unimportant one, in our primary and secondary schools or in 

 our Universities. The country is, however, now awakening to 

 the necessity of placing its house in order in this respect, and is 

 beginning to see that if she is to maintain her commercial and 

 industrial supremacy the education of her people from top to 

 bottom must be carried out on new lines. The question as to 

 how this can be most safely and surely accomplished is one of 

 transcendent national importance, and the statesman who solves 

 this educational problem will earn the gratitude of generations 

 yet to come. 



In conclusion, may I be allowed to welcome the unpre- 

 cedentedly large number of foreign men of science who have 

 on this occasion honoured the British Association by their 

 presence, and to express the hope that this meeting may be the 

 commencement of an international scientific organization, the 

 only means nowadays existing, to use the words of one of the 

 most distinguished of our guests, of establishing that fraternity 

 among nations from which politics appear to remove us further 

 and further by absorbing human powers and human work, 

 and directing them to purposes of destruction. It would 

 indeed be well if Great Britain, which has hitherto taken the 

 lead in so many things that are great and good, should now 

 direct her attention to the furthering of international organiza- 

 tions of a scientific nature. A more appropriate occasion than 

 the present meeting could perhaps hardly be found for the 

 inauguration of such a movement. 



But whether this hope be realized or not, we all unite in that 

 one great object, the search after truth for its own sake, and 



we all, therefore, may join in re-echoing the words of Lessing 

 " The worth of man lies not in the truth which he posse-ses 

 believes that he possesses, but in the honest endeavour whicl 

 puts forth to secure that truth ; for not by the possessioi 

 truth, but by the search after it are the faculties of 1 

 enlarged, and in this alone consists his ever-growing perfect 

 Possession fosters content, indolence, and pride. If God sh( 

 hold in His right hand all truth, and in His left hand the e 

 active desire to seek truth, though with the condition of 

 petual error, I would humbly ask for the contents of the 

 hand, saying, ' Father, give me this ; pure truth is only 

 Thee.' " 



SECTION A. 



mathematical and physical science. 



Opening Address by Sir Robert S. Ball, LL.D., F.R 

 President of the Section. 



A Dynamical Parable. 



The subject I have chosen for my address to you to-day 

 been to me a favourite topic of meditation for many years, 

 is that part of the science of theoretical mechanics which is usu 

 known as the " Theory of Screws." 



A good deal has been already written on this theory, b 

 may say with some confidence that the aspect in which I s 

 invite you now to look at it is a novel one. I propose to 

 an account of the proceedings of a committee appointed tc 

 vestigate and experiment upon certain dynamical phenom 

 It may appear to you that the experiments I shall describe 1 

 not as yet been made, that even the committee itself has 

 as yet been called together. I have accordingly ventured to 

 this address " A Dynamical Parable." 



There was once a rigid body which lay peacefully at rest, 

 committee of natural philosophers was appointed to mak( 

 experimental and rational inquiry into the dynamics of 

 body. The committee received special instructions. They^ 

 to find out why the body remained at rest, notwithstanding 

 certain forces were in action. They were to apply impul 

 forces and observe how the body would begin to move. 1 

 were also to investigate the small oscillations. These b 



settled, they were then to • But here the chairman ir 



posed ; he considered that for the present, at least, there 

 sufficient work in prospect. He pointed out how the quest 

 already proposed just complettd a natural group. "Let it su 

 for us," he said, *' to experiment upon the dynamics of this t 

 so long as it remains in or near to the position it now occuj 

 We may leave to some more ambitious committte the 

 of following the body in all conceivable gyratioi.s through 

 universe." 



The committee was judiciously chosen. Mr. Anharm 

 undertook the geometry. He was found to be of the utr 

 value in the more delicate parts of the work, though his colleaj 

 thought him rather prosy at times. He was much aided b) 

 two friends, Mr. One-to-One, who had charge of the ho 

 graphic department, and Mr. Helix, whose labours will be : 

 to be of mucli importance. As a most respectable if rather 

 fashioned member, Mr. Cartesian was added to the conmiit 

 but his antiquated tactics were quite out-manoeuvred by thos 

 Helix and One-to-One. I need only mention two more nai 

 Mr. Commonsense was, of course, present as an cx-oi 

 member, and valuable service was even rendered by 

 Querulous, who objected at fir^t to serve on the committee at 

 He said that the inquiry was all nonsense, because everybody k 

 as much as they wished to know about the dynamics of a i 

 body. The subject was as old as the hills, and had all 1 

 settled long ago. He was persuaded, however, to looV 

 occasionally. It will appear that a remarkable result of 

 labours of the committee was the conversion of Mr, Queru 

 himself. 



The committee assembled in the presence of the rigid bod 

 commence their memorable labours. There was the bod 

 rest, "a huge amorphous mass, with no regularity in its shape- 

 uniformity in its texture. But what chiefly alarmed the c 

 mittee was the bewildering nature of the constraints by w 

 the movements of the body were hampered. They had 1 

 accustomed to nice mechanical problems, in which a sm( 

 body lay on a smooth table, or a wheel rotated on an axle, 

 body rotated around a point. In all these cases the constra 



