26 MICHIGAN ACADEMY OF SCIENCE. 



relntion of bacteria to disease, and which had the small beginnings 

 ali-eadv referred to, even tuberculosis, the great white plague, is grad- 

 ually diminishing in virulence, the nuniber of cases is decreasing, the 

 death rate is diminishing, and if man continues to apply the rules for its 

 resii-ii'tiou which he has already devised, not more than a century or two 

 at most will pass until this disease will be known no more. Twenty 

 years ago there were wild hypotheses and vague conjectures concerning 

 the causation of certain diseases which greatly increased infantile mor- 

 tality. Man looked for the cause of these diseases in the sun spots, he 

 listened for it in the winds, he dug for it in the earth, he searched for 

 it in the water, but bacteriological study has shown him that the great 

 cause of cholera infantum and kindred diseases lies in milk which be- 

 comes poisonous on account of bacterial invasion and the elaboration of 

 toxins. Already it is estimated that of children sick with this disease, 

 thirty n'ore out of every hundred are saved now than was formerly pos- 

 sible. In other words, the per cent of recoveries has been increased from 

 fifty per cent to eighty per cent, and at the same time the number of 

 cases rf illness has been greatly reduced, — we cannot say just in what 

 proportion. These are some of the advantages that have come to man- 

 kind fi-om scientific research. Disease has been lessened, death has been 

 delayed, health an<l hapoiness have been multiplied. Are these not things 

 of value to the stnte? Not only have all these things been accomplished, 

 but possibly still greater good is to be found in the physical betterment 

 of those who have not been ill. 



This snme science of bacteriology has enabled us not only to limit the 

 spread of the infectious diseases, biit it has given us the most brilliant 

 results ever attained in the cure of disease. It has largely robbed diph- 

 theria of its horrors and has reduced the mortality from this disease 

 fr(;i)) over fifty per cent to less than five per cent in cases in which 

 antitoxin is user] immediately on the appearance of the disease. This is 

 a triumph in curative medicine which the most sanguine and visionarj 

 man of even ten years ago could scarcely have expected. The same science 

 has given us a means of combatting that rare but distressing disease 

 known as hydrophobia, and of preventing the sanif'. Who can say that 

 the world has not been benefited by the labors of the pioneers in bacte- 

 riology? ' Who can overestimate the discoveries of Pollender and T>a- 

 vaine, which to their contemporaries seemed to be at most of only triflinaj 

 importance? Who can foretell the benefits that may come to mankind 

 from what appears to be a trifling scientific discovery? 



The bacteriologist has not confined his labors to the study of those 

 microorganisms which cause disease, but he has gone farther and has 

 shown that some of these minute forms of life which we call germs are 

 capable of rendering great service to mankind. Only a few years ago it 

 was believed by many scientists that the amount of combiner] nitrogen 

 in the world is constantly decreasing, and that neither plants nor animals 

 are capable of utilizing the free nitrogen in the air. It was therefore 

 supposed to be a necessary conclusion that life on this planet must cease 

 as soon as all the combined nitrogen is used up. It was stnted thstt the 

 ex])losion of every ounce of gunpowder, whether the projectile' which it 

 cari'ied sti-uck a living object or not. carried death with it, inasmuch as it 

 less^ened the sum total of combined nitrogen in existence. The bacte- 

 riologist by his investigations has shown that this state of affairs is not 



