THE RELATION OF THE LABORATORIAN TO THE PRACTITIONER. 
173 
efforts in medicine coalesce or become intimately associated one 
with the other. 
It is the condition wherein some of the practitioners have 
allowed themselves to stray that has prompted me to write this 
paper, and if it has the power or tendency to cause them to wake 
up to their responsibilities as members of a profession and the 
duty they owe themselves, also the service and duty they owe 
their clients, which can only be rendered by men who have the 
proper conception of laborator work and science, I will feel that 
my feeble efforts have not been in vain. 
First, I will endeavor to deal with the microscope, its devel¬ 
opment and aid both to the laboratory man and practitioner. 
The existence of living plants or animals smaller than can be 
seen by the unaided eye was conjectured by several of the Greek 
philosophers and physicians, who used such theories in their 
speculations on the origin and cause of disease. Before the dis¬ 
covery of the microscope such speculations were without any 
basis in fact. Leeuwenhoek between the years o<f 1632 and 1723 
observed quite a variety of natural objects by means of the 
somewhat crude lenses of his own manufacture, and which 
proved on closer examination to be micro-organisms, some being 
motile and others motionless; all were found in the tartar from 
teeth and in various decaying organic materials. 
History teaches us that his subsequent correspondence with 
the Royal Society of London and the figures published in after 
years, leaves us without any doubt but that he actually observed 
bacteria. 
Each step in the efficiency of the microscope was followed by 
an advance in our knowledge of the micro-organisms, although, 
no doubt, speculations frequently outran the ability to see 
clearly. 
• 
The compound microscope has proven to be indispensable in 
the study of these minute forms of life. Since the introduction 
of this instrument, the degree of magnification, the clearness of 
definition and the mechanic arrangements for accurate focusing 
have been gradually improved until at the present time the homo- 
