A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. 



" To the solid ground 

 Of Nature trusts the mind which builds for rtjr."— Wordsworth. 



THURSDAY, MAY 2, 1901. 



' THE PHYSICIAN AS PHYSIOLOGIST. 

 A Contribution to the Study of the Blood and Blood- 

 pressure. By George Oliver, M.D. London, F.R.C.P. 

 Pp. xii + 276. (London : H. K. Lewis, 1901.) Price 

 7J. hd. 



IT is to be feared that most medical men who are 

 engaged in the active practice of their profession 

 have little idea of making a practical application of the 

 knowledge of physiology which they were at so great 

 pains to acquire during the student period of their career. 

 There are, however, many exceptions, and prominent 

 amongst them the author of the little work which it is our 

 present purpose to notice. Dr. George Oliver is fortunate 

 in that his sphere of practice has given him leisure during 

 several months in each year to study at length such 

 physiological problems as have appeared to him to bear 

 more directly upon the affections which he has been 

 mainly called upon to treat, and the result of his studies 

 has been a not immaterial addition to our knowledge of 

 the physiology of the circulation and of the blood. Such 

 addition has been obtamed largely by the devising of 

 methods which have more immediate applicability to the 

 human subject than those which are in common use in 

 the physiological laboratory. Not that Dr. Oliver has 

 neglected the more strictly scientific study of physiological 

 questions ; as is evidenced by his well-known investiga- 

 tions into the functions of the ductless glands. But in 

 the book before us the methods which are described are 

 solely those which, whilst maintaining a high standard of 

 scientific value, have a direct clinical application, and the 

 observations which are given are the results of such 

 application in the normal and occasionally in the 

 abnormal subject, extending over a period of some ten 

 years. 



The first method which is described is that for deter- 

 mining the amount of colouring matter (hiemoglobin) in 

 a sample of blood. For this purpose two chief procedures 

 have come into use clinically. The principle of the one 

 \ is that of taking a standard solution of hasmoglobin of 

 i NO. 1644, VOL. 64] 



known dilution and diluting the sample of blood to be 

 tested until its tint is similar to that of the standard 

 (method of Hoppe-Seyler, modified by Cowers by the use 

 of a picrocarmin gelatin, standardised to a known 

 strength of haemoglobin solution). The other proceeds 

 on the principle of diluting the sample of blood to a 

 constant extent and comparing it with glass tinted to 

 resemble solutions of haemoglobin of known degrees of 

 dilution (method of Fleischl). In practice this method is 

 the more simple and accurate, and has been adopted by 

 Dr. Oliver, who has, however, for adequate reasons dis- 

 carded the use of a coloured glass wedge which is the 

 characteristic of Fleischl's hremometer, and has adopted, 

 instead, a series of coloured glass discs which represent 

 gradations (percentages) in the amount of hremoglobin 

 of blood as compared with the normal. One of the most 

 important reasons for this modification of the method is 

 of great scientific interest ; for it was found by Dr. Oliver, 

 when making observations with Lovibond's tintometer 

 on the mixture of colours required to reproduce exactly 

 the tint of solutions of hEemoglobin of different strengths, 

 that it is not possible to take a glass of a tint the same as 

 that of a fairly strong solution of hemoglobin and, merely 

 by decreasing its thickness, to imitate the colour of a very 

 weak solution, but that it is necessary, also, to alter the 

 tone of colour with the change in strength of the solution, 

 e.g. for comparison with weaker solutions of hemoglobin 

 it is necessary to add more yellow to the tint of the glass 

 standards which are used for comparison with stronger 

 solutions. The second method described is one for rapidly 

 computing the number of coloured corpuscles in a given 

 sample of blood. The older method depends upon the 

 actual counting of the number in a measured quantity of 

 blood diluted to a known amount with an isotonic solution 

 of salts ; indeed, all methods of computation must be 

 standardised by this one. But such computation is 

 laborious and takes some 1 5 minutes at the very least, 

 whereas by the procedure devised by Dr. Oliver a satis- 

 factory result can be obtained in less than 5 minutes. 

 The method takes advantage of the fact that the coloured 

 corpuscles of the blood impart opacity to any fluid in 

 which they are suspended in sufficient number, and with 

 normal blood taken as the standard a less or greater 



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