DEVELOPMENT OF LIVING MATTER. 59 



scanty in morbid processes. In other words, a plastid will exhibit 

 coarse granulations, or it will be almost homogeneous-looking 

 under the microscope, owing to the large amount of living matter 

 in strong individuals of good constitution, while a plastid taken 

 from a person with weak or strumous constitution will be finely 

 granular, as but little living matter is present in it. 



Two years ago, I announced* that pus-corpuscles show 

 remarkable differences in their minute structure in different 

 individuals. Those from otherwise healthy and strong persons 

 are yellow, almost homogeneous, or coarsely granular, I said, 

 while those from broken-down, weakened, or strumous persons 

 are pale gray and finely granular. This fact has been made use 

 of in hundreds of cases, when pus-corpuscles, mainly in urine, 

 were brought by different physicians to my laboratory for exam- 

 ination, for telling whether the pus belongs to a good or a bad 

 constitution, of course without any knowledge of the patients 

 themselves. I was right in every instance ; not one mistake has 

 occurred. 



About one year ago I announced t that the colorless blood- 

 corpuscles also demonstrate striking differences as to their 

 minute structure, according to the general constitution. I said 

 that the colorless blood-corpuscles are coarsely granular and 

 slow in their amoeboid motions under the microscope, if taken 

 from healthy, vigorous, strong persons; on the contrary, they 

 are pale gray, finely granular viz., poorly provided with living 

 matter in broken-down or phthisical individuals. I expressed 

 my hopes that at some future time practical use might be made 

 of these differences. To-day my hopes have turned, after three 

 years' earnest study, into accomplished facts. 



The method of examination of the blood for our purpose is 

 extremely simple. We oil the edges of a thin covering-glass on 

 one side with a curled piece of paper, serving as a brush. Prick 

 with a pointed pin the palmar surface of the thumb, near the 

 wrist- joint, thus giving a good convex surface, and being least 

 incommoded by the injury. Squeeze out a small drop of blood, 

 the size of which has to be learned by some practice. Place the 

 glass slide on the drop for transportation, and immediately cover 

 up the specimen with the covering-glass, the oiled edges looking 

 toward the slide. Such a specimen holds the blood in a living 



* See page 32. 



t "On the Nature of Suppurative Processes of the Skin." A paper read 

 "before the County Medical Society of New York, 1877. Unprinted. 



