November 5, 19 14] 



NATURE 



267 



to the earth. Prof. Howe showed curves indicating 

 in some cases a marked maximum in the strength of 

 signals at midnight, and not, as one might expect, a 

 uniform strength during the whole period of darkness. 

 Dr. Eccles related some remarkable effects noted in the 

 neighbourhood of Pago-Pago, a ver\- lofty pinnacle 

 of highly insulating lava with a wireless station on 

 the summit. A ship near the island received distant 

 signals better when the island was in a position to 

 intercept the waves, as if the lava pinnacle deflected 

 the waves and concentrated them on the ship. 



MAI. ARIA AXD THE TRANSMISSION OF 

 DISEASES.^ 



Al^HEX I received the distinguished honour of 

 • * being invited by the committee of this school 

 to deliver the biennial Huxley Lecture — an honour 

 depending not only on the merits of the school itself, 

 but on the names of some of the greatest leaders of 

 the profession who have actually delivered the lecture 

 in the past — I conceived it to be my first duty to 

 select a theme which might be worthy of the occasion. 

 In that fine book, the " Historical Account of the 

 Charing Cross Hospital and Medical School," by Dr. 

 William Hunter, the eminent dean of the school, it is 

 shown that the founder of the hospital and the school. 

 Dr. Benjamin Golding, had already recognised so long 

 ago as 182 1 the importance of the study of tropical 

 medicine ; and it was therefore impossible that the 

 subject of my lecture of to-day should not lie in this 

 field. But the field is large ; and I should be losing 

 myself in the sand of too great diffusion were I even 

 to attempt a cursor}- survey of it. It was told, how- 

 ever — and gathered from the lectures of my prede- 

 cessors—that what my audience most desire to hear 

 would be, not remarks upon othe**' findings, but 

 rather a succinct histor)' of personal experiences, dis- 

 played from the widest point of view. I say this to 

 excuse my somewhat personal choice of theme. The 

 history will be a survey of the past ; and. though wider 

 for that reason, may be the more lacking in interest 

 to some of you who perhaps have already heard much 

 of these combats of a day already bygone. It is the 

 narrative of a very humble foot-soldier, but one, alas I 

 who is no longer employed by his country' at the front. 

 My subject will be malaria and the transmission of 

 diseases. 



First allow me to add a little wreath to the monu- 

 ment which the past lecturers have erected to the 

 memory of the great Huxley — and I should like to 

 place it upon a vacant spot. We all know Huxley as 

 the St. Paul of evolution, the bulldog of Darwin (as 

 he described himself), and the interpreter of Darwin's 

 profoundities to the world; and we also know him as 

 the patient and passionate investigator and the patient 

 and dispassionate thinker regarding phenomena. But, 

 in my opinion, he was still more — though not a higher 

 thing — a philosopher. Like thousands of others, I 

 have been fed and refreshed with those wonderful 

 essays, which, when, as his biographer tells us, his 

 hand grew heavy for dissections, he gave to the world 

 in his latter days. To my mind he had all of the 

 very first qualities required for true philosophy. The 

 claritv of his style, which he possessed in common 

 with Hobbes, Locke, and Hume and the great French 

 philosophers, was itself a guarantee of the genuine- 

 ness and completeness of his thought — so different 

 from the obscurity and pretension of style which many 

 philosophers from the days of Herakleitus onwards 

 have emploved to cover their emptiness. Secondly, his 

 mind was fiercely critical in its search for truth, and 

 he accepted nothing as fact which he himself had not 



1 The Huxley Lecture. Delivered at Charing Cross Ho«piml on Monday, 

 Noveml>:ra, by >ir,Ronald Ross, K.C.B.. F.R.S. 



NO. 2349, VOL. 94] 



endeavoured to probe into to the depths. Thirdly, no 

 one has ever doubted that his aim was, not to astonish 

 or to defeat or to persuade, so much as to reach the 

 actual truth of every matter which he dealt >\ ith ; and 

 this serves to distinguish him from many of those 

 who work in a field which is particularly open to 

 pretence and even to charlatanry. We all trust Hux- 

 ley. He may have been wrong for want of facts, but 

 not for want of sincerity and effort. It is the fashion 

 of one generation to decry the labours of the preceding 

 generation ; but as time advances this error is put 

 right, and Huxley will be seen from the distance to 

 soar more and more above the eminent writers of his 

 own time. 



I can imagine nothing that would have delighted 

 him more than the bearing of recent advances in 

 science on the medicine of the tropics. Indeed, this 

 latest victory of science, achieved after his time, may 

 be considered as a culminating point in the practical 

 application of science to the needs of suffering 

 humanity. The victory- has been won, not only by 

 medicine, but by medicine and zoology fighting side 

 by side — by those two great branches of science in 

 which he himself was so proficient. Let me now 

 describe the details of the campaign. 



It is curious that though the transmission of disease 

 is a matter of such vast import to ever}- one of us, it 

 has received so little investigation in the past. Even 

 up to the middle of last century, our inquiries had led 

 us little further than what I call the subscience of the 

 subject — that is, we distinguished, classified, and 

 named our various bodily inflictions. We also did 

 more ; for we had ascertained empirically the physio- 

 logical and therapeutical effect of many drugs — 

 quinine, opium, mercury, iodide of potassium, 

 ipecacuanha, and others ; and also that great genius 

 Jenner had discovered a wonderful fact which is at the 

 basis of the theory of immunity, prevention, and 

 cure. But the causes of disease and their mode of 

 transference still remained hidden. At that epoch, 

 however, and afterwards, Pasteur, Koch, Lister, Beh- 

 ring, and others created the science of bacteriology. 

 But still, though the information thus obtained was 

 of prime importance to the pathologist, the physician, 

 and the surgeon, we still remained much in the dark 

 regarding one important issue, namely, the exact path 

 of transmission of many diseases from man to man. 

 Bacteria are easily saprophytic, and may have many 

 paths of transmission, and, I fear, that we are still 

 ver\- much in doubt as to the most important of these 

 numerous routes. We thought, and are often still 

 inclined to think, that the germs of disease come to 

 us from any place where they may be scattered — that 

 they have not precise routes and points of entr>-. 

 This leads us to a very vague prophylaxis. We under- 

 take all kinds of disinfections in order to destroy the 

 enemv, wherever he may possibly lurk ; and the conse- 

 quence is that -we often fail to check infection as 

 certainly as we wish. It has been the great result of 

 the inquiries which I will now proceed to describe that 

 they have, as the French say, precised our knowledge 

 upon this point in connection with many diseases, and 

 have indeed led to the discover}- of another and most 

 wonderful route of infection which until recently was 

 undreamed of by the profession and the public. 



The armies of science, like those of nations, com- 

 mence with small beginnings and advance in parallel 

 columns. If one column is checked by insuperable 

 difficulties, the others endeavour to outflank the point 

 of resistance ; and a victor}- is often won by this means 

 in science as in war. (Excuse my military similes, 

 which appear to be appropriate at this hour.) That 

 column of science which conquered the domain of 

 bacteriology was brought to a standstill for some time 

 as regards the exact transmission of disease until the 



