January 27, 19 16] 



NATURE 



609 



rural sanitation. Their good effects have been quickly 

 (Innonstrated on a large scale. 



Boards of health in several American municipalities 

 ind States have lately undertaken a large work of 

 public teaching by means of widely distributed posters 

 and leaflets on contagia and the carriers of contagious 

 disease. They have found themselves obliged to take 

 this action, because they learnt by experience that the 

 spread of contagious disease cannot be prevented by 

 enacting laws and employing inspectors to procure 

 the execution of those laws, unless the citizens them- 

 selves co-operate actively and with intelligence in the 

 execution of the measures which applied biology pre- 

 <> ribes. Thus, the public at large must be taught 

 lat if streets, yards, and vacant lots of a city are kept 

 ean, garbage is removed promptly and kept covered 

 antil removed, and the privy vault and the manure- 

 heap are abolished, the number of flies and vermin 

 in and about dwellings will be much reduced. Reduc- 

 tion in the amount of sexual vice and venereal disease 

 can be effected by teaching parents and young people 

 about the dangers of syphilis and gonorrhoea for the 

 individual, and their fatal effects on family happiness. 



Irhirdly, this immense development of biological 

 jwledge and skill must have lessons to teach about 

 I means of other progress, similar or contrasted. 

 The most important lesson which the great advance 

 applied biological science teaches is that the treats 

 «»tnt of human evils and wrongs in the future should 

 be preventive for the mass, as well as curative for the 

 individual. This is the reason for the great change 

 which is taking place in the profession of medicine. 

 The main functions of that profession are to be, not 

 the curing of individuals who are already suffering 

 from disease, but the prevention of the spread of 

 disease from individual to individual in the community, 

 and the eradication or seclusion of the causes, sources, 

 or carriers of communicable diseases. The same great 

 change needs to be wrought in all the callings which 

 deal with prevention of crimes and misdemeanours. 

 Society must concern itself, not chiefly with the isola- 

 tion, temporary or permanent, of the individual mur- 

 derer, thief, or forger, but with the extermination or 

 repair of the genetic, educational, or industrial defects 

 which cause the production of criminals. Since it is 

 often found through medical and psychological exam- 

 ination that the prostitute, forger, robber, or poisoner 

 is physically as well as morally defective, it is probable 

 that biological science will in the future contribute 

 largely to the prevention as well as cure of such bodily 

 defects, and hence of those moral defects which in an 

 appreciable fraction of the population result in crimes. 

 When humane persons learn, for example, that three- 

 fifths of all the prostitutes in New York City are 

 feeble-minded girls and women, they become interested 

 at once in the better care and treatment under medical 

 dirction of the feeble-mindpd, in the means of making 

 a trustworthy diagnosis of feeble-mindedness in chil- 

 dren, and in preventing the feeble-minded from repro- 

 ducing their like. These are all biological problems; 

 and the progress of biological inquiry during the past 

 fifty years is sufficient to afford the means of solving 

 on a large scale these fundamental social problems. 

 It is to biological science in the departments of mental 

 disease and psycho-therapy, as well as to educational 

 theory and practice, that we must look for new- 

 methods of discipline and education in prisons, re- 

 formatories, and houses of correction. Preventive 

 medicine and sanitary reform have shown the right 

 way of dealing with these chronic sores in the body 

 politic. 



The interrelations of the sciences are vividlv taught 

 by the history of biology during the past eighty years. 



Biological science is deeply indebted to physical science 

 for the new instruments of precision which the bio- 

 logist uses in determining and recording his facts. 

 The telephone, the X-ray, and all the electrical appa- 

 ratus for recording fluent observations and makmg 

 certain note of very minute portions of time and space 

 have been invaluable additions to the resources of the 

 biological investigator. Many of the instruments- 

 ^which are indispensable in botanical and zoological 

 laboratories were not invented for biological uses, but 

 for physical or chemical uses. The dental practice 

 called orthodontia has profited greatly by the use of 

 the X-rays, because the Rontgenograph exhibits the 

 precise abnormalities in the jaws and the concealed 

 teeth which need to be remedied. The art of photo- 

 graphy has contributed much to biological research 

 and biological teaching, although developed and im- 

 proved more for commercial and astronomical pur- 

 poses than for biological. ITie microscope itself and 

 the immersion lens, tools indispensable in the study 

 of micro-organisms of all sorts, were long used in 

 pure botany and zoology, before they became the neces- 

 sary tools of applied biological science. 



Again, the long series of successful applications of 

 biological science illustrates strikingly the impossibility 

 of drawing any fixed line of demarcation between pure 

 and applied science, or of establishing an invariable 

 precedence for one over the other. Sometimes an appli- 

 cation is suddenly made of one fragment of an accu- 

 mulation of knowledge which men of science have 

 made without thought of any application, and some- 

 times a bit of knowledge successfully applied stimu- 

 lates purely scientific workers to enter and ransack the 

 field from' which the bit came. The latter process 

 was strikingly illustrated when the large group of the 

 mosquitoes were studied with ardour, because two 

 species became famous, one as the carrier of malaria, 

 and the other of yellow fever. The anatomy and 

 habits of the typhus fever louse had been worked out 

 many years before that insect became known as a 

 carrier of typhus fever. Long before salvarsan was 

 proved valuable for killing the syphilis micro-organism 

 in the human body, a series of organic compounds 

 derived from benzol and containing arsenic had been 

 elaborately studied, and the means of producing them 

 made known by chemists who had not the faintest 

 suspicion that a safe remedy for the most destructive of 

 contagious diseases in the human species was later ta 

 be found in a new member cA the series having a 

 reduced arsenical potency. The man of science 

 often feels, and not infrequently expresses, contempt 

 for applications of science and for the men that make 

 them. Sometimes the seeker for valuable applications 

 of scientific knowledge feels no interest whatever in 

 researches of which no industrial application seems 

 feasible or probable, and confesses publicly this lack 

 of interest. The facts seem to be that all such feelings 

 are narrow and irrational ; that no mortal can tell 

 how soon a practical application of a scientific truth, 

 which seems pure in the sense that it has no present 

 application, may be discovered ; and that, on the other 

 hand, innumerable applications are nowadays made of 

 truths which five years or fifty years ago seemed as 

 remote from all human interests as the observation 

 attributed to Thales, that a bit of amber rubbed with 

 a piece of silk would repel pith-balls suspended by 

 fine filaments. Yet all magnetism and electricity with 

 their infinite applications hark back to this experiment 

 by Thales and to Galvani's observation of twitchings 

 in a frog's legs. 



The new physiological studies of the bodily changes 

 accompanying or produced by pain, hunger, fear, and 

 rage already promise a new interpretation of human 

 behaviour, and therefore a new policy for humai) 



NO. 2413, VOL. 96] 



