OUR GREGARIOUSNESS IN ERROR. 105 



seldom condescends to regard. No speculative Chemist 

 is allowed to call a substance an acid which will unite 

 with no base, which exhibits none of the properties of 

 an acid ; no Physicist is allowed to assume the exist- 

 ence of electricity, where none of the conditions of 

 electricity exist, and none of the phenomena (except 

 those to be explained) are manifest. But we who 

 study Biology in any dejDartment, whether Physiology, 

 Zoology, or Botany, are allowed by the laxity of current 

 practice, and the want of a doctrine, to call a coloured 

 spec an eye, in the absence of all proof of its having 

 the structure or functions of an eye ; we are allowed to 

 assume the existence of nerves, where no trace of a 

 nerve is discernible ; we are allowed to drag in " elec- 

 tricity," or the " will,'' as efficient causes of anything 

 we do not understand ; and we fill Text-books and 

 Treatises with errors which give way before the first 

 sceptic who investigates them. 



We are very sheep in our gregariousness in error. 

 When one bold or stupid mutton takes a lea]), all leap 

 after him. It is rare to find men doubtino; facts, still 

 rarer to find them doubting whether the facts be cor- 

 rectly co-ordinated. Our books are crowded with 

 unexamined statements, which we never think of ex- 

 amininoj. Do we not all believe that the mamiificent 

 Cleopatra, regardless of expense, dissolved in her wine- 

 cup a pearl of great price, as if it had been a lump of 

 sugar ? Is not the " fact '' familiar to every one ? Yet, 

 if you test it, you will find the fact to be that pearls 

 are not soluble in wine ; the most powerful vinegar 



