THE SCIENCE OF MICROSCOPY. 317 



interpreted with the caution which belongs to an exact science ; in 

 tine, that a real "science of microscopy" should form the critical 

 basis of every practical judgment expended on microscopic objects. 



If by microscopy be meant the massing together of a number 

 of details taken as described or interpreted by writers who have not 

 made the observations, and who are not restrained in their specu- 

 lation by any doubt of the facts themselves, then certainly a 

 million of facts will not make a science of microscopy, however 

 well marshalled by the literary labor expended on them, not 

 unfrequently to the detriment of natural history ! But if each 

 observation be studied on its own merits, and we enquire whether 

 the warrant of truth has been set upon it by the exercise of a proper 

 control in making it, then we touch the question whether there is 

 a science of microscopy. For an observation is good or bad 

 according as it is a true or false inference from appearances 

 presented in the microscope, not according to its real or supposed 

 value when used in any particular research. The bad observation, 

 which becomes a source of error when accepted as a fact in natural 

 science, must eventually discredit microscopy as a science. The 

 good observation stands for acceptance on its own right, even if 

 opposed to current belief, and may become a possible starting point 

 of higher deduction, although it may not immediately suggest any 

 compensating idea for the illusion which it has destroyed. As an 

 integral and independent fact, its reality must be established by a 

 critical scrutiny of the circumstances under which it is seen. And 

 as in ordinary circumstances all seeing is not believing, so in the 

 extraordinary conditions of microscopic vision the observer is even 

 more responsible than his instrument for the true definition of 

 what he sees. 



If it be objected to these remarks that they in no way touch the 

 judgment of the experienced microscopist, who has learnt to 

 discriminate between false and true microscopic effects, and is not 

 likely to commit any gross errors of observation, it maybe rejoined 

 that the assertion of discriminating experience begs the whole 



