FREE BOOKS

Author's List




PREV.   NEXT  
|<   25   26   27   28   29   30   31   32   33   34   35   36   37   38   39   40   41   42   43   44   45   46   47   48   49  
50   51   52   53   54   55   56   57   58   59   60   61   62   63   64   65   66   67   68   69   70   71   72   73   74   >>   >|  
story of leucocytosis, which after the precedent of Virchow was in general referred to an increased production on the part of the lymphatic glands; and further by the imperfect distinction between leucocytosis and incipient leukaemia, which was drawn almost exclusively from purely numerical estimations. It was only after Ehrlich had introduced the new methods of investigation by means of stained dry preparations, that the histology of the blood received the impulse for its second period. We owe to them the exact distinction between the several kinds of white blood corpuscles, a rational definition of leukaemia, polynuclear leucocytosis, and the knowledge of the appearances of degeneration and regeneration of the red blood corpuscles, and of their degeneration in haemoglobinaemic conditions. The same process, then, has gone on in the microscopy of the blood that we see in other branches of normal and pathological histology: by advances in method, advances in knowledge full of importance result. It is therefore little comprehensible, that an author quite recently should recommend a reversion to the old methods, and emphatically announce that he has managed to make a diagnosis in all cases, with the examination of fresh blood. At the present time, after the most important points have been cleared up by new methods, in the large majority of cases, this is not an astonishing achievement. For any difficult case (for instance the early recognition of malignant lymphoma, certain rare forms of anaemia, etc.) as the experienced know, the dry stained preparation is indispensable. The object of examining the blood, is certainly not to make a rapid diagnosis, but to investigate exactly the individual details of the blood picture. To-day, we can only take the standpoint, that everything that is to be seen in fresh specimens--apart from the quite unimportant rouleaux formation, and the amoeboid movements--can be seen equally well, and indeed much better in a stained preparation; and that there are several important details which are only made visible in the latter, and never in wet preparations. As regards the purely technical side of the question, the examination of stained dry specimens is far more convenient than that of fresh. For it leaves us quite independent of time and place, we can keep the dried blood with few precautions for months at a time, before proceeding to further microscopic treatment; and the examination of the
PREV.   NEXT  
|<   25   26   27   28   29   30   31   32   33   34   35   36   37   38   39   40   41   42   43   44   45   46   47   48   49  
50   51   52   53   54   55   56   57   58   59   60   61   62   63   64   65   66   67   68   69   70   71   72   73   74   >>   >|  



Top keywords:

stained

 

methods

 
examination
 

leucocytosis

 

knowledge

 

histology

 

degeneration

 
important
 

specimens

 

preparations


preparation

 

details

 

advances

 
diagnosis
 
corpuscles
 

purely

 

leukaemia

 
distinction
 

experienced

 

investigate


anaemia
 

examining

 
indispensable
 

object

 

instance

 

recognition

 

difficult

 

treatment

 

achievement

 
microscopic

proceeding

 

malignant

 

precautions

 
months
 

lymphoma

 
picture
 
astonishing
 

visible

 

question

 
equally

convenient

 
standpoint
 
independent
 

technical

 

leaves

 

amoeboid

 

movements

 
formation
 
rouleaux
 

unimportant