BAKER ON A NEW SCIENCE,— THAT OF SANITATION. 83 



Incidentally, too, a comparison of these two general facts leads to 

 another important fact, namely, that at least four-fifths of the cases of 

 the scarlet fever and diphtheria experienced in Michigan must have been 

 spread directly or indirectly from previous cases. Otherwise they 

 would not be prevented by isolation and disinfection. 



Please notice that the results in one year are not very widely different 

 from the results in other years, so that a prophecy relative to the year 

 1891, for instance, from the experience in preceding years, would have 

 approached the actual experience in 1891. 



1 think I have now demonstrated that the art of sanitation has now 

 been put upon a scientific basis, that the' results are capable of numeri- 

 cal expression, in fact that there is a Science of Sanitation. 



