560 FRAGMENTS OP SCIENCE. 



received the name of pebrine, was the product of a parasite 

 which first took possession of the intestinal canal of the 

 silk-worm, spread throughout its body, and filled the sack 

 which ought to contain the viscid matter of the 'silk. 

 Thus smitten, the worm would go automatically through 

 the process of spinning when it had nothing to spin. Pas- 

 teur followed this parasitic destroyer from year to year, 

 and led by his singular power of combining facts with the 

 logic of facts, discovered eventually the precise phase in 

 the development of the insect when the disease which 

 assailed it could with certainty be stamped out. Pasteur's 

 devotion to this inquiry cost him dear. He restored to 

 France her silk husbandry, rescued thousands of her 

 population from ruin, set the looms of Italy also to work, 

 but emerged from his labors with one of his sides per- 

 manently paralyzed. His last investigation is embodied in 

 a work entitled "Studies on Beer," in which he describes 

 a method of rendering beer permanently unchangeable. 

 That method is not so simple as those found effectual with 

 wine and vinegar, but the principles which it involves are 

 sure to receive extensive application at some future day. 



There are other reflections connected with this subject 

 which, even were they now passed over without remark, 

 would sooner or later occur to every thoughtful mind in 

 this assembly. I have spoken of the floating dust of the 

 air, of the means of rendering it visible, and of the perfect 

 immunity from putrefaction which accompanies the contact 

 of germless infusions and moteless air. Consider the woes 

 which these wafted particles, during historic and pre-his- 

 toric ages, have inflicted on mankind ; consider the loss of life 

 in hospitals from putrefying wounds; consider the loss in 

 places where there are plenty of wounds, but no hospitals, 

 and in the ages before hospitals were any where founded; con- 

 sider the slaughter which has hitherto followed that of the 

 battlefield, when those bacterial destroyers are let loose, 

 often producing a mortality far greater than that of the 

 battle itself;, add to this the other conception that in times of 

 epidemic disease the selfsame floating matter has frequently, 

 if not always, mingled with it the special germs which pro- 

 duce the epidemic, being thus enabled to sow pestilence and 

 death over nations and continents consider all this, and 

 you will come with me to the conclusion that all the havoc 

 of war, ten times multiplied, would be evanescent if com- 

 pared with the ravages due to atmospheric dust. 



