Clinical diagnosis : the bacteriological, chemical, and microscopical evidence of disease / by Rudolf v. Jaksch ; translated from the second German edition by James Cagney ; with an appendix by Wm. Stirling.

  • Cagney James.
Date:
1890
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Licence: Public Domain Mark

Credit: Clinical diagnosis : the bacteriological, chemical, and microscopical evidence of disease / by Rudolf v. Jaksch ; translated from the second German edition by James Cagney ; with an appendix by Wm. Stirling. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    Haycraft and Williamson’s Method. [The method recently introduced by Ilaycraft and Williamson'’ is very suitable for clinical purposes, since by its means the alkalinity of the blood may be determined quantitatively from a single drop of the fluid. A number of red litmus papers is prepared, containing varying quantities of oxalic or some other acid. One of these is such as is found by experiment barely to give a reaction with normal blood, and this is made the basis of a series of test-papers answering to different degrees of alkalinity. The strength of each is estimated by means of a solution of caustic potash of known concentration. The papers are glazed, and dipped for a second or two in liquid paraffin and then dried. In con- ducting the experiment, a drop of blood is drawn from the finger (previously well cleansed) and placed upon a paper of medium strength. There it is allowed to rest for ten seconds. Sufficient of the plasma has then soaked in. The blood is wa.shed off, and the reaction, if any, is at once apparent. Should this be so, a paper containing more acid is employed ; but if there be no reaction, a weaker one is taken. Suppose now it is found that the blood will give a reaction with the sixth and not with the seventh paper, the former is then taken as the expression of its alkalinity. But it is known that an — solution of an alkali will give the same reaction, therefore the alkalinity of the blood will be “ This is perhaps not absolutely true, for probably the blood plasma does not percolate so readily into the litmus paper as does a watery solution of an alkali. In this case, however, the error will be uni- form,” and will not vitiate the conclusion in a series of comparative investigations.*] The author’s experiments ** have led him to the conclusion that the alkalinity of loo cc. healthy human blood corresponds to 260-300 mgrm. of NaOH. Canard,^ who adopts a similar method, gives the equivalent as 203-276 mgrm. NaOH; while Mya and Tassinari,^^ from experiments upon blood drawn from the veins, quote very much higher figures (516 mgrm.). The alkalinity of the blood is often diminished in fever. The author has invariably found it reduced considerably in uraemia, as well as in certain toxic states, as carbonic oxide poisoning. [It is also reduced in persistent vomiting.] In organic disease of the liver, leukaemia, pernicious anaemia, and diabetes, the author has found such a diminution as was capable of being expressed in figures, and in this (the condition of the blood in chlorosis alone excepted) he is borne out by the researches of Grdberd'^ Cantani'^'^ is of opinion that the blood in cholera may exhibit an acid reaction even during life. III. SPECIFIC GRAVITY OF THE BLOOD.—The specific gravity of healthy human blood has been stated at i.045-1.075 by Landois,^'^ and 1.035-1.068 by Lloyd Jonesd^ It is usually lower in women than in men; and the last-mentioned authority has shown that it is highest * [I am indebted to the courtesy of Dr. J. B. Haycraft for a personal com'munication on the subject discussed in the text. He informs me tliat he has already derived important clinical inferences from the application of his method. By means of it he has ascertained that the reaction of the blood in different conditions may vary ivs widely as that of the urine.—(En.)]