THE WHITE BLOOD CORPUSCLES 201 



puscles has been estimated at 19-32,000,000,000. They are especially 

 numerous in the new-born, counts of 15,000-19,000 per cu. mm. being 

 not infrequent. They become fewer in number shortly after birth, 

 but again increase during infancy, when a value of 30,000 per cu. mm. 

 cannot be regarded as abnormal. From the first to the sixth year the 

 values range between 13,000 and 7000 per cu. mm. A second decrease 

 takes place in adult life. This is again followed by an increase in 

 old age. The ingestion of food rich in protein raises the count, but 

 maximal values are not obtained until two or three hours after meals. 

 Very pronounced increases of this character constitute the so-called 

 assimilation or digestion leukocytosis. Fasting lowers the count, 

 while muscular activity^ and massage^ raise it. 



A transitory increase above the physiological maximal value is 

 designated as leukocytosis, while a reduction below the minimal value 

 is called hypoleukocytosis or leukopenia. In accordance with the 

 data given above, it is advisable to classify leukocytosis as physio- 

 logical and pathological, this division being based solely upon the cause 

 of the increase. A pathological leukocytosis, for example, arises in 

 the course of many febrile reactions and especially after hemorrhages 

 and in consequence of suppurative processes. It is also possible to 

 produce this condition by the administration of quinin, turpentine, 

 albumose, nucleic acid, bacterial products and extracts of thymus, 

 spleen and bone-marrow. A leukopenia of marked degree frequently 

 follows exposure to the Rontgen rays. 



The method employed in determining the number of the leukocytes is the 

 same as that made use of in counting the red cells, but as a larger drop of blood 

 is needed in this case, the pipet and counting chamber must be somewhat larger 

 in size. 3 In order to render the white corpuscles more conspicuous, the red cor- 

 puscles must first be destroyed by adding a small quantity of acetic acid to the 

 diluting fluid. It is also possible to add some coloring material to the latter so that 

 the total count may at the same time be amplified by a differential count.* In 

 general, however, it is advisable to differentiate these cells in a stained smear, 

 because abnormal forms of leukocytes are difficult to recognize in the counting 

 chamber. 



The Chemical Composition of the White Corpuscles. — The direct 

 chemical analysis of the white corpuscles meets with the difficulty that 

 it is quite impossible to secure these cells in sufficient numbers. 

 Their chemical characteristics, however, have been studied in an 

 indirect way by making use of the so-called pus-corpuscles which are 

 always present in tissues which have been invaded by pus-producing 



^Zuntz, Physiologie des Marsches, Berlin, 1901. 



2 Zangemeister and Wagner, Deutsche med. Wochenschr., xxviii, 1902, 549. 

 ' A special counting cell has been devised by Brener (Berliner klin. Wochen- 

 schr., xxxix, 1902, 954. 



^ Tiirk (Wiener klin. Wochenschr., xv, 1902, 715) recommends a mixture of: 



Glacial acetic acid 3 c.c. 



Distilled water „ 300 c.c. 



Gentian violet, 1 per cent, aqueous solution 2 to 3 c.c. 



Also see: Zollikofer, Zeitschr. f. wissensch. Mikr., xvii, 1900, 313. 



