ACTION OF ACIDS ON THE RED CORPUSCLES. 401 



instances the nucleus gradually becomes coloured, without the 

 colour being discharged from the border of the corpuscle, 

 although the substance of the corpuscle becomes proportion- 

 ately colourless. A similar coloration of the nucleus occurs also 

 with a two per cent, solution of boracic acid, when applied to 

 the corpuscles dried on a slide. If the corpuscles are so modi- 

 fied by freezing, by shocks of electricity, or by ether or 

 chloroform (the changes effected by which will be subse- 

 quently considered) that they have yielded up their colouring 

 matter completely to the serum, and they are then treated with 

 a two per cent, solution of boracic acid, the nuclei still acquire 

 their deep tint from the colouring matter contained in the sur- 

 rounding fluid. Brlicke also observed the corpuscles discharge 

 their nuclei from the action of boracic acid. 



/. If it be desired to ascertain what alterations are effected 

 in the blood corpuscles by small variations in the degree of 

 acidity or alkalinity of the reagent, it is requisite, as has been 

 shown by W. Addison,* in order to avoid the action of the 

 water of the solution, to give a certain degree of concentration 

 to the fluid by the addition of a small proportion of sugar or of 

 salt. In such investigations it will be found, as he has correctly 

 stated, that on the addition of an acid fluid, as of a solution of 

 cane sugar weakly acidified with hydrochloric acid, the blood 

 corpuscles possess, in all instances, smooth contours, and exhibit 

 an increased degree of refraction ; whereas on the addition of 

 an alkaline fluid, as of a solution of common salt rendered 

 feebly alkaline with liquor potassse, the blood corpuscles become 

 granulated and rough. 



Appearances essentially similar are produced with still 

 greater clearness by passing weak currents of electricity through 

 the blood. That the corpuscles quickly become tuberculated 

 and spinous in the vicinity of the alkaline pole was observed 

 by Neumann,f who also saw the formation of the fibres 

 described by Addison. 



The change of form corresponding to the action of weak 



* Quarterly Journal of Microscopical Science, 1861; Jan., Transact., p. 

 20; April. Journal, p. 81. 

 t Loc. cit., pp. 679681. 



