MICROSCOPIC A I, DIAGNOSIS. 33 



outnumber the red, owing to their larger size. The excess appears 

 very marked, however, if there is one white to ten red. 



OTHER ELEMENTS IN BLOOD. 



Small elements have been found in the blood varying from 

 i -6000 to i -8000 of an inch in diameter, having a bright, shining 

 look, and the same color as the red corpuscles. Observers, who 

 have described these bodies, call the disease under which they are 

 found microcythemia. These elements may be identical with the 

 syphilitic corpuscles of Lostorfer. 



A few cases have been reported where fi'larise have been found 

 in the blood. Notably the cases described by Beale in the fourth 

 edition of The Microscope in Medicine, p. 480. Also in the Queckett 

 Journal of Microscopy for July, 1881. 



They are found quite frequently in the blood of the Chinese, at 

 least when in their native country. The persons may, apparently, 

 enjoy good health at the time. A, mysterious phenomenon is con- 

 nected with the periodicity of these organisms. One writer says that 

 between four and six in the afternoon the filariae begin to appear 

 and they increase until midnight, then diminish until nine or ten in 

 the morning, when they have entirely disappeared. This periodicity 

 appears quite independent of the habits of the patient. 



To ascertain the globular richness of the blood the corpuscles 

 must be counted in a known quantity. 



It is necessary, first, to select a proper diluting fluid. Dr. 

 Frederick P. Henry, of Philadelphia, has given this subject a great 

 deal of attention, and he prefers a solution of sulpho-carbolate of 

 soda, although the borax-urine solution of Keyes' is highly recom- 

 mended. 



Dr. Henry prefers the Hayem and Nachet instrument, diluting 

 the blood one to two hundred and fifty. 



Should any of our readers desire to investigate this subject, 

 they can get great help from a perusal of the Cartwright Prize Essay 

 for 1881, published by F. A. Davis, and written by Dr. Henry, both 

 of Philadelphia. 



Virchow, Meckel, Donders, Vogel and Von Duben have report- 

 ed the presence of cells in the blood. The cells were supposed to be 

 the epithelium from the walls of the vessels. But little is known on 

 this subject and the cases described have been found in the blood 



