926 



SCIENCE 



[N. S. Vol. XLII. No. 1096 



to prepare teachers or leaders for Girls' 

 Canning Clubs and Home Demonstration 

 "Work. These courses cover cooking, can- 

 ning, sewing, market gardening, poultry- 

 husbandry, plant propagation, and rural 

 sanitation. Their good effects have been 

 quickly demonstrated on a large scale. 



Boards of health in several American 

 municipalities and states have lately un- 

 dertaken 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, be- 

 "cause they learnt by experience that the 

 spread of contagious disease can not be 

 .prevented by enacting laws and employing 

 inspectors to procure the execution of 

 those laws, unless the citizens themselves 

 cooperate actively and with intelligence in 

 the execution of the measures which ap- 

 plied biology prescribes. Thus, the public 

 at large must be taught that if streets, 

 yards, and vacant lots of a city are kept 

 clean, garbage is removed promptly and 

 kept covered till 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. 

 Eeduction in the amount of sexual vice and 

 venereal disease can be effected by teach- 

 iag parents and young people about the 

 dangers of syphilis and gonorrhea for the 

 individual, and their fatal effects on fam- 

 ily happiness. 



Thirdly, this immense development of 

 biological knowledge and skill must have 

 lessons to teach about the means of other 

 progress, similar or contrasted. 



The most important lesson which the 

 great advance in applied biological science 

 teaches is that the treatment of human 

 evils and wrongs in the future should be 

 preventive for the mass, as well as cura- 



tive for the individual. This is the rea- 

 son 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 communi- 

 cable diseases. The same great change 

 needs to be wrought in all the callings 

 which deal with prevention of crimes and 

 misdemeanors. Society must concern it- 

 self, not chiefly with the isolation, tem- 

 porarj' or permanent, of the individual 

 murderer, 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 psy- 

 chological examination that the prosxitute, 

 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 re- 

 sult 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 be- 

 come interested at once in the better care 

 and treatment under medical direction of 

 the feeble-minded, in the means of making 

 a trustworthy diagnosis of feeble-minded- 

 ness in children, and in preventing the 

 feeble-minded from reproducing 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 bio- 

 logical science in the departments of men- 



