340 FRAGMENTS OF SCIENCE 



glistening epidermis which prevented complete wetting of 

 their surfaces." 



I pointed out in 1876 that the process by which an 

 atmospheric germ is wetted would be an interesting sub- 

 ject of investigation. A dry microscope covering -glass 

 may be caused to float on water for a year. A sewing- 

 needle may be similarly kept floating, though its specific 

 gravity is nearly eight times that of water. Were it 

 not for some specific relation between the matter of the 

 germ and that of the liquid into which it falls, wetting 

 would be simply impossible. Antecedent to all develop 

 ment there must be an interchange of matter between the 

 germ and its environment; and this interchange must ob- 

 viously depend upon the relation of the germ to its encom- 

 passing liquid. Anything that hinders this interchange 

 retards the destruction of the germ in boiling water. In 

 my paper, published in the "Philosophical Transactions" 

 for 1877, I add the following remark: 



It is not difficult to see that the surface of a seed or germ 

 may be so affected by desiccation and other causes as prac- 

 tically to prevent contact between it and the surrounding 

 liquid. The body of a germ, moreover, may be so indu- 

 rated by time and dryness as to resist powerfully the insinu- 

 ation of water between its constituent molecules. It would 

 be difficult to cause such a germ to imbibe the moisture nec- 

 essary to produce the swelling and softening which precede 

 its destruction in a liquid of high temperature. 



However this may be whatever be the state of the sur- 

 face, or of the body, of the spores of Bacillus subtilis, 

 they do as a matter of certainty resist, under some cir- 

 cumstances, exposure for hours to the heat of boiling 

 water. No theoretic scepticism can successfully stand in 



