54 MANUAL OF HISTOLOGY. 



. 



litus, on the other hand, there may be an excess of red cor- 

 puscles, while there is a diminution of their haemoglobin. In 

 ansemia, from hemorrhage, there is an actual loss both of cor- 

 puscles and of haemoglobin in those that remain. 



To facilitate the estimation of haemoglobin, an instrument 

 has been devised by Malassez and Verick (Paris), called the 

 hcemochromometer, 1 which is easily manipulated, and bids fail- 

 to establish some facts of -practical utility (see Archives de 

 Phys., 1877, p. 1). 



It consists of a hand-screen, to which a movable prismatic 

 trough, containing a colored fluid, is attached, and a modified 

 Potain pipette. By means of this apparatus the richness of 

 the blood in haemoglobin, and the maximum quantity of oxy- 

 gen which it can absorb, may be determined. To use the ap- 

 paratus the pipette is first filled up to a certain point with the 

 blood to be examined, and then diluted with 100 parts of water. 

 The reservoir of the pipette is then filled with the diluted 

 blood. The screen has two holes ; behind one of these the 

 prismatic trough is made to slide up and down, the color of the 

 fluid contained in it of course varying in intensity, according 

 to the extent of the upward and downward motion.' Behind 

 the other opening the reservoir of the pipette is secured by 

 means of a little elastic ring. The screen is now held against 

 the light (preferably white light ; sunlight is to be especially 

 avoided), and the trough moved until the color of the blood 

 mixture is matched by its own color. Then the figure on the 

 scale attached to' one side of the trough is read off, and this 

 indicates, by reference to the table annexed to the apparatus, 

 the points to be determined. If the blood to be examined be 

 deeply colored, the aqueous blood-mixture is made in the pro- 

 portion of to 100 ; if it be but slightly colored, in the propor- 

 tion of 2 to 100. 



BIBLIOGRAPHY. 



WELCKER. Pragervierteljahreschr. XLIV., p. 60. 1854. Zeitschr. f. rat. Med. 



3, XX., p. 280. 



ScnoLTZE, MAX. Archiv f. mikrosk. Anat. I., p. 35. 1865. 

 HOI.LETT. Strieker's Manual of Histology. New York, 1872. 

 WOODWARD. Am. Jour, of the Med. Sci., Jan., 1875. N. Y. Med. Rec., Jan. 31, 1880. 



1 To be obtained of J. F. Beynders & Co., New York city. 



