62 INTEODUCTION. 



\of labor for the ultimate determination of the truth, many times 

 as great as that which would have sufficed in the first instance, 

 had the original observations been accurately made and faithfully 

 recorded. Others, again, are too slow and hesitating ; and fix 

 their attention too much upon details, to be able to enter into 

 the real significance of what may be presented to the vision. 

 Although ignorance has doubtless much to do in producing both 

 these faults, yet they both have their source in mental tendencies 

 which are not corrected by the mere acquisition of knowledge, 

 and which are very inimical, not merely to its fair reception, but 

 also to the formation of a sound judgment upon any subject 

 whatever. The habit of guarding against them, therefore, once 

 acquired in regard to Microscopic observation, will be of invalu- 

 able service in every walk of life. Not less important is it (as 

 i has been already shown), to keep our observations free alike 

 from the bias of preconceived ideas, and from the suggestive 

 influence of superficial resemblances ; and here, too, we find the 

 training which ^Microscopical study affords, especially when it is 

 prosecuted under the direction of an experienced guide, of the 

 highest value in forming judicious habits of thought and action. 

 To set the young observer to examine and investigate for him- 

 self, to tell liini merely where to look and (in general terms) what 

 to look for, to require from him a careful account of what he 

 sees, and then to lead him to compare this with the descriptions 

 of similar objects by Microscopists of large experience and un- 

 questionable accuracy, is not only the best training he can receive 

 as a Microscopist, but one of the best means of preparing his 

 mind for the exercise of its powers in any sphere whatever. 



It cannot be too strongly or too constantly kept in view, that 

 the value of the results of Microscopic inquiry will depend far 

 I more upon the sagacity, perseverance, and accuracy of the ob- 

 1 server, than upon the elaborateness of his instrument. The most 

 perfect Microscope ever made, in the hands of one who knows 

 not how to turn it to account, is valueless ; in the hands of a 

 careless, a hasty, or a prejudiced observer, it is worse than value- 

 less, as furnishing new contributions to the already large stock 

 of errors that pass under the guise of scientific truths. On the 

 other hand, the least costly Microscope that has ever been con- 

 structed, how limited soever its powers, provided that it gives no 

 false appearances, shall furnish to him who knows what may be 

 done with it, a means of turning to an account, profitable alike 

 to science and to his own immortal spirit, those hours which 

 might otherwise be passed in languid ennui, or in frivolous or 

 degrading amusements,' and even of immortalizing his name by 

 the discovery of secrets in Nature as yet undreamed of. A very 



' '• I have seen,'' says Mr. Kingsley, " the cultivated man, craving for travel and suc- 

 cess in life, pent up in the drudgery of London work, and yet keeping his spirit calm, 

 and his morals perliaps all the more righteous, by spending over his Microscope even- 

 ings which would too probably have gradually been wasted at the theatre.'' 



