Is it a defense to an alleged nuisance that the defendant was on the ground first? He may contend that he built his brick kiln, when all the surrounding land was vacant and thereafter the plaintiff voluntarily purchased and built on ground adjoining the kiln. This alleged defense is spoken of as "coming to a nuisance." Most of the cases, however, hold that this makes no difference. The injury arises only when the plaintiff's enjoyment is interfered with, but if he can not build a house, then the defendant would be in effect permitted to destroy the value of the plaintiff's property. If he must leave his land vacant it is worthless or at least its value is greatly impaired.
Assuming that the law is clear and that if the defendant is doing certain acts he is maintaining a nuisance, the plaintiff is always confronted by the necessity of proving by legal evidence that such acts are being done. This is often a difficult task. Ordinarily the defendant has large interests at stake and fights desperately to the last ditch.
The extent of the task of establishing by legal evidence the existence of a nuisance is shown in a recent case in which the question was whether one state could be enjoined from interference with the riparian rights of another state.
The state of Missouri brought suit against the state of Illinois to prevent the discharge of the sewage of Chicago by means of an artificial channel into the Des Plaines River, whence it entered the Illinois River and then the Mississippi. If this was a nuisance, by what law was it to be decided, that of Illinois or Missouri? The United States Supreme Court held that it could decide such controversies between states. Otherwise there would be no means of determining contests between states which in the absence of federation would be decided by war. But the court held that the rules applicable to private riparian owners did not necessarily apply between states and that the injury must be greater than a private injury to warrant relief. Missouri contended that the daily discharge of 1,500 tons of poisonous filth into this channel caused great injury to the public health in the state of Missouri since St. Louis and other cities took their water from the Mississippi River. Missouri showed that the number of deaths from typhoid fever had largely increased after the opening of the Chicago drainage canal. Missouri also showed by the presence in increased numbers in the Illinois River of the Bacillus coli communis, which it was agreed was an index as to the organic matter in the water, that the contamination was increased, but Illinois denied that injury to health had been caused, and so both sides conducted experiments to show the duration of life and capacity for travel of the Bacillus typhosus. It was conceded that typhus, cholera, dysentery, anthrax and tetanus are water-borne diseases and that it was practically impossible to discover the bacilli of typhoid in running water. It was proved by means of floats that the journey from Chicago
