THE MICROSCOPE AS A MEANS OF DIAGNOSIS. 651 



son have shown, to reveal, during life, the existence of this pecu- 

 liar pathological condition in the kidney. 



But while, on the one hand, we urge upon the student the 

 importance of the study of microscopy, and direct his attention, 

 by way of proof, to the brilliant labors of the German School of 

 Histologists ; on the other, we must caution him against its ex- 

 clusive cultivation, to the neglect of the other established and 

 reliable modes of investigation of which the intelligent physician 

 avails himself, in the daily routine of business. " You must not 

 suppose," writes Dr. Bennett, 1 "that an additional method of 

 gaining information implies abandonment of those, the utility 

 of which has stood the test of experience. Men must learn the 

 every-day use of their senses ; must know how to feel, hear, and 

 see, in the same manner as they did before instruments were 

 invented. We don't see the stars less clearly with our naked 

 sight, because the telescope is necessary for an astronomer. 

 Neither should a physician observe the symptoms of a disease 

 less accurately because he examines the chest with a stethoscope, 

 or a surgeon be less dexterous with the knife, because it is only 

 by means of the microscope he can determine with exactitude 

 the nature of a tumor." " We should learn to distinguish be- 

 tween the mechanical means necessary for arriving at truths, and 

 those powers of observation and mental processes which enable 

 us to recognize, compare, and arrange the truths themselves. In 

 short, rather endeavor to observe carefully and reason correctly 

 on the facts presented to you, than waste your time in altering 

 the fashion and improving the physical properties of the means 

 by which facts are ascertained. At the same time, these are ab- 

 solutely necessary; and perhaps no kind of knowledge has been 

 so much advanced in modern times by the introduction of in- 

 struments and physical means of investigation, as that of medi- 

 cine. These enable the practitioner to extend the limits to 

 which otherwise his senses would be limited. I do not say em- 

 ploy one to the exclusion of the other, but be equally dexterous in 

 the use of all. Do not endeavor to gain a miserable reputation 

 as a microscopist, or as a stethoscopist ; but by the appropriate 

 application of every instrument and means of research, seek to 

 arrive at the most exact diagnosis and knowledge of disease, so 

 as to earn for yourselves the title of enlightened medical 

 practitioners." 



As with all other mechanical aids to the senses, the microscope, 

 to be successfully applied in medicine, requires a degree of skill 

 in its manipulation not to be acquired at once, but by repeated 

 and persevering practice. Let the student, therefore, not be dis- 

 couraged by the many failures and uncertainties which, to a 

 greater or less extent, must necessarily accompany his early 

 efforts. Let him remember that exact and accurate habits of 

 observation are acquired slowly and almost insensibly, and that, 

 in attempting to obtain proficiency in any practical art or science, 



1 Introduction to Clinical Medicine. 



