Some Observations on the Haemolysis of Blood by Hyposmotic and Hyperosmotic Solutions of Sodium Chloride

In the Lancet for April 2lnd, 1904, Sir A. E. W1 right anid lKiliter, in describilng at new llmethod of testing the blood anid the urine, state that complete haemolysis takes place wheni a dark coloratioln is obseirved in a mnixture of onie voluiime of sulspeislion of erythrocytes with olne voluimie of a progressive dilutioni of a deci-niormal sodiuml clhloride solutioni in a capillarytube. Later oIn, Wright aind Ross2 pOitollt that instead of mnaking a prepalrationt of the suspensioil of the red corl)uscles, all that is requiied is to take a imeasured voluimie of tlhe blood aniid to imiix wi-itlh it t-o volumes of the p)rogressive (illutiont of the (leeci-IIoru:lal sodiuml chloride soluitioll, and tlhen to observe wi-heni the dark colorationi takes place. It will be seen fromii the above, that it is assumed, firstly, that it is possible to bring about complete haemiolvsis by imixing one volumle of blood with twi-o voltumes of a sufficiently dilute soltutionl of sodiuml chloride, aniid secondly, tlhait the point of complete haeiimolysis can be deterimined by lettinig lig:ht fall obliquely 111)011 caplllhary tubes cOntaillilig the iixtutire, it beinig supposed to be airrived at w-hen there is a (lark coloration of the blood, anid thele is no briglht appealranice to be seeni in it. In this way, Wrright and Ross conclu(le tlhat the average European bloodl haemolI-ses conmpletely with two parts of sodium chloride solutioln.