58 JOURNAL OF THE [March, 



Roll it up into one with another of its kind, and it couldn't tell 

 you itself a minute afterward which of the two it had really been 

 a minute before." 



I will also refer to another subject that has received much 

 attention. Many years since, peculiar forms of life had been 

 found with decomposing animal and vegetable matter. Many 

 forms are described by Ehrenberg, as Vibrio, Bacterium, etc. 

 They are now named Micrococcus, Bacterium, Bacillus, Vibrio, 

 Spirillum, and they are simple granules, duplicate cells, rods and 

 spiral filaments, nearly all possessing the power of motion, usually 

 by flagella, — or vibrating hairs, — and can be seen satisfactorily 

 only by the best lenses. It remained for Professor Tyndall to 

 show that no decomposition can take place without this life ; 

 and that solutions of materials that are ready for decomposition 

 will not be changed if placed in an atmosphere of perfectly pure 

 air. Further investigation has shown that characteristic forms 

 of minute life accompany disease ; and we have not only Bacillus 

 tuberculosis of Consumption (No. 34), and Cholera Bacillus (No. 

 35), but a host of other Bacilli. 



The question that interests us is. Do these forms produce dis- 

 ease, or do they only accompany the disease as their product ? 

 Every house-wife knows quite as well as Prof. Tyndall, that perish- 

 able substances can be kept in a jar for a long time without change, 

 by hermetically sealing the jar at the temperature of boiling 

 water. But the workers with the microscope have found the 

 reason why : and that is, that these forms of Bacilli and Bacteria 

 that always accompany decomposition, are necessary to it ; that 

 they are mostly destroyed by heat at the temperature of boiling 

 water ; and that the germs of these forms are everywhere pres- 

 ent in ordinary air, and no decomposition takes place if such air 

 be excluded after the destruction of these forms. Very natur- 

 ally it is inferred that the Bacteria produce the decomposition, 

 and also that the Bacilli of Cholera, Tuberculosis, etc., produce 

 these diseases. 



These are yet open questions. Much of the life-history of 

 these forms has been learned, many experiments have been made, 

 and the literature of the subject is becoming large. Although 

 inoculation with some forms has produced disease, there is a 

 great diversity of opinion in regard to this matter ; and many 

 more experiments are needed to decide this momentous question. 



