POLICE POWER 35 



know beforehand something of his fjersonal rights 

 and liabilities. Kats are nuisances because they 

 destroy grain and other property worth millions 

 of dollars each year in the United States. Scien- 

 tific advances have shown that they are active in 

 the spread of plague and very likely of other dis- 

 eases. They are great travelers. An infected rat 

 might easily find his way into a freight car in 

 New Orleans, and land in St. Louis or Chicago, 

 and there infect other rats, that in turn might in- 

 fect human beings. Though there are infected 

 rats in New Orleans, it would hardly be suspected 

 by the uninitiated that there Avas danger of con- 

 tracting plague in Chicago, and a case might be- 

 come well developed before the correct diagnosis 

 would be made. So long as it was thought that 

 tlie rat was only a danger to property the state 

 officers might very reasonably leave the protec- 

 tion of property from this danger to the individual 

 OAvners; but now that the danger to the public 

 is known, and it is a danger which lurks unsus- 

 pected, the state not only would have a right, but 

 it might be considered a duty, to enact laws which 

 would restrict the breeding places of those pests, 

 and also require the rat-proofing of buildings in 

 cities of a given size. 



22. Treatment of Nuisances. A nuisance may 

 be prohibited, abated, or regulated. It may be 

 prohibited, by a state statute, a city ordinance, or 

 by an injunction issued by the court. Violation 

 of the prohibition makes the violator subject to 

 criminal prosecution. It may be regulated, as by 

 ordinances which make the sale of liquor permis- 

 sible only within certain hours. More frequently 



