17,1 Ash: The Physician and the Laboratory 51 
we owe the patient an abject apology. A negative report 
should not always be considered conclusive. It requires per- 
sistence and a certain amount of luck, and sometimes repeated 
examinations, to exclude that particular factor, especially if the 
clinical picture is insistent. Given a primary sore of syphilis, 
you must remember that a certain time must elapse before the 
Wassermann test will be positive and that a negative dark field 
finding in such a sore that has been receiving local treatment 
means practically nothing. The albumin is not constantly pre- 
sent in a case of chronic nephritis; a drink of whiskey taken a 
few hours before blood is drawn for the Wassermann may ren- 
der an otherwise positive serum negative. The spinal fluid in 
meningitis does not always give the picture it should. There- 
fore, the negative report must usually be considered with more 
than a grain of salt. 
What, on the other hand, does a positive report mean? Is 
it really the key to the case, or does it merely speak for an in- 
tercurrent condition that may have little bearing on the symptoms 
at hand? The interpretation, therefore, of the laboratory find- 
ings and their proper application are very important features 
of the relation between doctor and laboratory. My pride has 
often received a jolt when I have been forced to realize what 
an unimportant part the laboratory has played in the study of 
a particular case. In following such cases through their course, 
even to death and autopsy, with the organs spread before us in 
plain view on the table, the answer has still been hidden from 
us, and we could but throw up our hands and realize how little 
after all our knowledge really is of those essential vital pro- 
cesses that differentiate us as kings of the earth from hulks of 
clay. 
I have been pessimistic enough, for there is much good in 
the laboratory. We think of the wonderful old stars of our 
profession, those pioneers who toiled so skilfully and painstak- 
ingly in so much medical darkness, and we marvel at the results 
they attained. The elder Gross did not need a modernly equip- 
ped laboratory with a trained pathologist to diagnose cancer 
of the breast for him; Hunter knew nothing of those peculiar 
biological properties of the blood serum that were later to be 
harnessed in the complement fixation test for syphilis, but he 
usually knew a hard chancre when he saw it. These men used to 
the utmost the things they possessed. They observed and remem- 
bered. I present these and the other staunch pillars of the past 
as my chief argument for the proposition of the great need of 
