400 THE BLOOD, BY ALEXANDER ROLLETT. 



diluted, the second of the above-mentioned modes of operation 

 frequently passes into the first, because in very diluted acids 

 the action of the acid is complicated with that of the water. 



The former of the above-mentioned effects is best exhibited 

 by means of acetic acid, in solutions containing twenty 

 grammes of pure acetic acid in 100 cubic centimeters of water, 

 and upwards. The beautiful staining of the nucleus, with the 

 colouring matter of the blood which then occurs, was first 

 mentioned by Henle,* and has been corroborated by Kneut- 

 tinger ;-f- it is exhibited in the most beautiful and convincing 

 manner if the blood of a frog or triton is allowed to float into 

 acetic acid : the blood sinks in the acid, and the dregs of the 

 vessel can then be examined. 



The non-nucleated corpuscles of Man and Mammals are first 

 rendered spherical by the action of acetic acid, and then lose 

 their colour, in which condition they remain for a considerable 

 period. 



BriickeJ has subjected to a special investigation the changes 

 that are effected on corpuscles of the fresh blood of the Triton 

 by the action of a two per cent, solution of boracic acid, and 

 we shall now proceed to describe them. Soon after the addition 

 of the solution the corpuscles seem to be converted into ellip- 

 soids, as after the action of certain proportions of water, the 

 nuclei being often eccentrically situated ; they ultimately, to 

 a greater or less extent, become spherical. Forms are also 

 obtained similar to those that have already been mentioned as 

 occurring after the addition of water or saline solutions (fig. 

 73). In other corpuscles the nucleus alone appears of a 

 deep colour, the remaining substance of the corpuscle being 

 pale or completely colourless, and separated by a smooth con- 

 tour line from the surrounding fluid, as after the action of 

 many other acids in certain degrees of dilution. Direct obser- 

 vation of the action of boracic acid under the microscope 

 renders it evident that the latter form does not necessarily pro- 

 ceed from any of the foregoing. In the greater number of 



* Allgemeine Anatomie, p. 431. 



t Loc. cit., pp. 28, 29. 



% Sitzungslerichte der Wiener Akademie, Band Ivi., p. 79. 



