P OP ULAR MIS CELL ANY. 



425 



place, gradually adapt itself to the new 

 conditions, and even, in the course of suc- 

 cessive transformations, acquire new facili- 

 ties for adaptation. If four vessels, care- 

 fully cleansed, are tilled with different fluids 

 such as carbolic acid, urine, Cohn's min- 

 eral plant-food, and Pasteur's fluid all 

 clear of bacteria, and a drop of the same 

 putrefactive mixture is added to each of 

 them, they will, in the course of forty-eight 

 hours, show very different degrees of dis- 

 turbance, according to their adaptation to 

 promote the growth of the infective organ- 

 isms. If the organisms themselves are ex- 

 amined, they will be found, although all 

 originating from the same source, to be 

 only similar, not identical. Even Pasteur, 

 who stoutly advocates the specificity of 

 the ferments, has been obliged to admit a 

 few exceptions to his theory. Dr. Wernich 

 had already called attention to observations 

 by himself and others which tended to 

 show that fungoids, which seemed harmless 

 growths on the more exposed tissues, might, 

 if the capacity of the body for resistance 

 should be depreciated, become aggressive, 

 and develop dangerous disorders. Grawitz 

 cultivated a mold that grows on sour solids, 

 but does not flourish in the bodies of ani- 

 mals, through successive generations, till he 

 adapted it to a higher temperature than its 

 natural one, to pastes, sweetened and alka- 

 line fluids, and to blood. A living animal 

 inoculated with spores of the last variety 

 died in a few hours in consequence of a 

 general development of the fungoid vegeta- 

 tion, particularly in the kidneys and liver. 

 Dr. Wernich believes that he has evidence 

 that the strength of the infective qualities 

 of these organisms may be greatly increased 

 by an accommodative culture. Cultivation 

 in substances unfavorable to their growth 

 is, on the other hand, found to cause a de- 

 preciation of their inoculative efficacy. If 

 we select the most favorable substance for 

 the growth of a mold, and plant upon it 

 the most vigorous stocks we can obtain, we 

 will soon perceive unmistakable indications 

 of an increase of vigor. The period re- 

 quired for the development of the germs is 

 shortened, and the organisms give way to 

 their successors of the next generation in 

 continually diminishing periods. The infec- 

 tive force becomes so much greater that 



the slightest contact is sufficient to effect a 

 transplantation to a new medium, and the 

 greatest pains are necessary to prevent a 

 transfer without apparent contact of spores 

 of the same kind as those which, subjected 

 to unfavorable conditions of culture, re- 

 quire painful attention to induce them to 

 take root in any new soil. A similar devel- 

 opment of activity and infective power may 

 be observed in the case of epidemics. The 

 germs of disease do not exhibit their full 

 vitality at once, as do poisons when ab- 

 sorbed, but require a period of incubation 

 and the favor of diminished power of re- 

 sistance in the body before they can exhibit 

 their full effect. The first cases are in- 

 definite, and hardly recognizable in their 

 real character, and affect only the weakly; 

 as the epidemic acquires strength, its mani- 

 festations are mere determinate, and it af- 

 fects all. The manner in which this growth 

 of activity is produced may be illustrated 

 by experiments that have been made in the 

 inoculation of animals, in which an increase 

 in infective power has been very distinctly 

 perceived to accompany each successive 

 transfer from one animal to another. Dr. 

 Wernich suggests that there are some ques- 

 tions relating to the subject that need yet 

 to be explained, and that it will not be safe 

 to form definite conclusions upon it until 

 after further investigation. 



Explosive Force of Coal-Dnst. The 



Rev. H. C. Hovey has communicated to the 

 " American Journal of Science " the results 

 of the investigations of Mr. Gilpin, In- 

 spector of Mines for Nova Scotia, into the 

 part played by coal-dust in spreading and 

 augmenting the explosions which took place 

 in the Albion mine in November of last 

 year. The mine was thoroughly ventilated, 

 and was reported by the night-watchman, 

 an hour before the explosions began, to be 

 free from gas, except in small and harmless 

 quantities. Yet the explosions, once begun, 

 were continued at intervals till the mine 

 was all aflame and had to be flooded. On 

 examining the gallery shortly after the origi- 

 nal explosion, dead bodies of men and horses 

 were found six hundred yards from the 

 shafts, and the wood-work was splintered, 

 but nothing bore any marks of fire, " and 

 the conclusion was plainly justifiable that 



