BLOOD AND BLOOD EXAMINATION 



By a. LAZARUSj Chahlottenburg (Berlin) 



The examination of the blood, in comparison with other clinical investi- 

 gations, has very slowly forced its way into practice. While the conscientious 

 physician rarely fails to make an examination of the urine or of the sputum 

 in cases in which it seems necessary or at all useful, examinations of the blood, 

 even the simplest, have up to the present been resorted to by a very small 

 number of practitioners. 



The object of this article is to call attention to the necessity of clinical 

 blood investigation, and to describe the simplest methods. It will then become 

 a matter of routine to examine the blood no less frequently than the various 

 other secretions, excretions, or inflammatory products. 



Of course, the importance of the results of blood investigation in different 

 diseases of the blood is not always equally great. In the cases in which a dis- 

 ease of the blood or of the blood-producing organs comes into question, an 

 examination of the blood is more important than an)^ other clinical research, 

 and often this alone will guide us to a definite opinion. This is true of the 

 various forms of anemia, of leukocytosis and leukemia, of many diseases of the 

 bone-marrow, and in certain parasitic diseases of the blood. [There can 

 hardly be said to be " many diseases of the bone-marrow " recognized to-day, 

 and the blood has never yet helped much to advance our knowledge in this 

 direction. . 



Parasitic diseases of the intestine and other internal organs should be men- 

 tioned here among those in which blood examination is of great diagnostic 

 value. — Ed. J 



The number of cases is, however, disproportionately greater in which an 

 examination of the blood, although actively complementing other methods, is 

 alone not decisive. It may be of value in the differential diagnosis between 

 various acute infectious diseases ; it may make clear the nature of many cases 

 of poisoning; in the prognosis of many bacterial diseases we may under some 

 circumstances find points of support in the condition of the blood ; the prophy- 

 laxis and therapy of malaria, according to Eobert Koch's investigations, can 

 only be made certain by regular examinations of the blood, and to these many 

 other examples might be added [e. g., trichiniasis, filariasis, uncinariasis, 

 trypanosomiasis. — Ed.] . 



That the history under some circumstances may become enriched by an 

 examination of the blood is obvious if we remember that after recovery from 



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