152 THE BLOOD. 



0'95 to 1-05 in men, and from '9 to 1 in women. 1 This "blood 

 quotient " has been also termed " the worth " of a corpuscle. 2 



The more exact methods for the determination of the amount of haemo- 

 globin in blood are dealt with elsewhere (see article on Haemoglobin). For 

 clinical purposes a comparison with a standard colour of the colour of the 

 blood diluted to a known amount is found to give sufficiently accurate results. 

 The chief methods used have been (1) That of Gowers, 3 who employs picro- 

 carmine gelatin as a standard ; (2) that of F. Hoppe-Seyler, 4 who combines 

 the haemoglobin with carbonic oxide, and compares it with a standard solution 

 of CO haemoglobin ; and (3) that of v. Fleischl, who used a wedge of tinted 

 glass as a comparison. The method of v. Fleischl is by far the most con- 

 venient. It has been greatly improved by Oliver, who has adapted to it 

 the principle of Lovibond's tintometer. 5 rfThus modified it takes the form of 

 a series of tinted glasses, one of which represents accurately the colour of a 

 measured amount of normal blood diluted with water and placed in a flat 

 glass cell of a certain size, whilst the others represent percentages of haemo- 

 globin below and above the normal (Fig. 22). The blood is measured in a 

 pipette similar to that shown in Fig. 21, a. 6 



The number of white corpuscles in a cubic millimetre of blood is 

 usually stated as 10,000, but it varies greatly even in health. By far 

 the larger proportion (70 to 90 per cent.) are of the finely granular 

 oxyphil variety. 7 Of the rest less than 5 per cent, are coarsely granular 

 oxyphil cells, while the remainder, except a few which are hyaline, 

 contain basophil grannies. 



Injection of many substances (peptones, nuclein, leech extract) into 

 the vessels causes an immediate and marked diminution in the number 

 of the leucocytes, chiefly affecting the finely granular kind (leucocytopenic 

 phase, Lowit) ; 8 it is followed by an increase in their number (leucocytotic 

 phase). Acute local inflammation causes similar changes, but the 

 diminution in the number of leucocytes also largely affects the coarsely 

 granular cells, whereas the after increase is mainly in the finely 

 granular. Hankin noticed that the blood clots more readily when the 

 coarsely granular cell is scanty; this may explain the more ready 

 clotting of blood in inflammatory conditions. 



The blood possesses, in the presence of free oxygen, a certain power of 

 producing oxidation in readily oxidisable substances, which may be added to 

 it, such as salicylaldehyde. 9 This property it shares with some of the 

 tissues (spleen, liver, lung, thyroid, kidney, thymus), while other tissues 

 show no such tendency (muscle, brain, pancreas). The oxidation power is 

 greater in young subjects than in the adult. 10 On the other hand, the blood 

 contains a substance or substances ("reducing substances" of Pfliiger) which 

 greedily appropriate any free oxygen which may be present in the plasma, 



1 Oliver, loc. cit., p. 1705. 



2 Garrod, Med.-Chir. Trans., London, vol. Ixxv. p. 191. 



3 Lancet, London, 1878, vol. ii. p. 822. 



4 Ztschr. f. physiol. Chem., Strassburg, Bd. xvi. S. 505. See also G. Hoppe-Seyler, 

 ibid., 1896, Bd. xxi. S. 461, and Winternitz, ibid., S. 468. 



5 Lovibond, "Measurement of Light and Colour Sensations." 



6 For more complete details of the method see Oliver, loc. cit., pp. 1699-1703. 



7 Sherrington, Proc. Roy. Soc. London, 1894, vol. Iv. ; Kanthack and Hardy, Journ. 

 Physiol. , Cambridge and London, 1894, vol. xvii. p. 81. The earlier literature is given by 

 Sherrington. 



8 "Studien z. Phys. u. Path. d. Brutes," Jena, 1892. 



9 Salkowski, Ztschr. f. physiol. Chem., Strassburg, 1882, Bd. vii. S. 115 ; Centralbl. f. 

 d.med. Wissensch., Berlin, 1892, Bd. xxx. S. 489. 



10 Abelous and Biarnes, Arch, de physiol. norm, etpath., Paris, 1895, pp. 195 and 239. 



