68 A MANUAL OF BACTERIOLOGY 



It has been recorded that a certain foreign medi- 

 cal professor mistook minute globules of fat for so 

 many micrococci ; and certainly the illustrations in 

 his paper indicated that such was really the case. 

 Therefore, let all bacteriologists, young and old, be 

 very sceptical at times as to what they think they 

 see with the highest powers of the microscope. 

 Without wishing to detract an iota from the honesty 

 of purpose and truth of our fellow-workers, we are 

 sure that a good deal unintentionally has been said 

 to have been seen with the microscope which has 

 never been seen at all. We set to work longing to 

 discover something newer than the last new thing. 

 We hope to find it, we begin to think we have 

 found it, and we may go so far as to make ourselves 

 believe we really did see it once. The event must 

 be recorded ; we proclaim it, and in so doing pro- 

 pagate error. Therefore, let it be borne in mind 

 that to use the highest powers with accuracy re- 

 quires continual practice ; even when the retina of 

 the eye is sensitive enough to appreciate light-waves 

 proceeding from such organisms as the smallest 

 micrococci. 



Staining Cover-glass Preparations and Tissues. To 

 prepare a cover-glass preparation for staining, a 

 sterilised cover-glass is smeared with the microbian 

 matter (solid or liquid), or with blood, pus, etc., by 

 means of a sterilised needle or capillary pipette. 

 The excess of material is squeezed out by means of 

 an additional cover-glass placed over the original 

 one. The two glasses are then separated, each bear- 

 ing a small portion of the microbian matter. After 



