132 THE AMEKICAN MONTHLY [June, 



has been destroyed by the hUoors and investigations of many scientists, 

 more especially by the elaborate and long continued experiments of 

 Prof Tyndall, of England. 



Thousands of persons in various parts of the world find remunera- 

 tive emplovment in putting up for table use meats, fish, fruits, and 

 other perishable articles of food by what is known as the canning pro- 

 cess. In this method of preserving food, the tin cans or other recepta- 

 cles are placed in watery solutions of various salts, which boil at a 

 temperature considerably above the temperature of boiling water ; by 

 being treated in this wav the living germs in them become desti'oyed, 

 and they become sterilized ; whilst in this condition antl whilst the steam 

 is still escaping from the can, the opening is dexterously closed by a 

 drop of solder. These cans all contain articles of tbod, which would 

 be utterly destroyed and made putrid by exposure for a few days, or 

 even hours, to the atmospheric air. The traveller in the arctic re- 

 gions, or in the wilds of tropical Africa, if the cans are uninjured, 

 expects to find the contents fit for table use, even when they have been 

 kept for years. 



Men who know nothing of science are willing to invest millions of 

 money in the various industries concerned in the preservation of foods, 

 with a firm faith that their capital is safely and profitably invested. 

 This could not be the case if the spontaneous generation of the micro- 

 organisms, which cause fermentation and putrefaction, were possible. 



The life-history of micro-organisms when considered with regard 

 to their rapidity of multiplication, presents a field of study which 

 should give us valuable information with regard to the truth of the 

 theory of evolution. It is very probable, and indeed very certain, that 

 the study of a bacterium and its progeny for a few days gives us a 

 series of generations more numerous than have existed among the higher 

 classes of animals since the earth was fitted for their habitation. The 

 rapidity of the growth and multiplication of bacteria is as fiir beyond 

 the capacity of the human mind to conceive, as it is to attempt to 

 measure the distances of the stars in the heavens, or to count their 

 numbers. 



Professor Jluckner, of Germany, states the time usually required for 

 one microbe or germ to become two, by the process of division, is fif- 

 teen minutes. At this rate it is computed that a single microbe would 

 produce in twenty-four hours a million million million times the 

 present human population of the earth. Professor Law, in a paper pub- 

 lished recently in the Pharmacctttical Era^ estimates that a single 

 bacterium dividing and redividing would produce in forty-eight (48) 

 hours, if undisturbed, 281,500,000,000, and in bulk would fill a half- 

 pint measure, all produced in two days, from a single germ measuring 



the Yg^oyoo" P^^'t of ^''' inch. 



Pathological bacilli are just as numerous where found, and divide as 

 rapidly. Professor Bdllinger states that a cubic-centimeter (about one- 

 fourth of a fluid drachm) of phthisical sputum (from a case of pul- 

 monary consumption) contains from Sio, 000 10960,000 tubercle bacilli. 

 In an ordinarily copious expectoration the consumptive patient deposits 

 nearly a million bacilli into his cup, and in an ordinary day he throws 

 30 or 40 millions of these micro-organisms into the world. Then, at 

 a low estimate, ten thousand tuberculous patients, now living in New 

 York city, daily expectorate some 300,000,000,000 tubercle bacilli. 



