BY DR. KLEIN. 33 



projections on the surface of the corpuscles become less marked 

 in consequence of the levelling up of the intermediate parts ; 

 and, although there are many which do not resume the bicon- 

 cave form, being still saucer-shaped, they all have even surfaces. 

 If the carbonic acid is replaced by air, the corpuscles again 

 become horse-chestnut shaped. This reaction may also be 

 witnessed several times in succession. The disappearance of 

 the stellate form may be explained on \he supposition that a 

 spontaneously coagulated constituent is redissolved under the 

 action of carbonic acid. Colorless corpuscles show their nuclei 

 when acted on by carbonic acid, but are otherwise unaltered. 



Action of Electricity. If it is intended to subject blood 

 to the action of electrical discharges, or of the constant or in- 

 terrupted current, we place a small drop of blood on the slide 

 (Fig. 6) in such a position that, when it is covered, it spreads 

 between the two poles of tinfoil, which we connect by means 

 of either of the appliances shown in the figure wih the secon- 

 dary coil of the induction apparatus. 



According to Rollett, it is advisable, in using electrical dis- 

 charges, that the tinfoil points should be six millimetres apart. 

 The Ley den jar should have a surface of 500 square centi- 

 metres, and give a spark one millimetre long. If, then, the 

 discharges succeed each other at intervals of from three to five 

 minutes, the following changes are observed in the colored cor- 

 puscles of man. Firstly, the circular disks become slightly 

 crenate. This effect gradually increases, the corpuscles become 

 rosette-shaped, then mulberry-shaped, and finally, by the acu- 

 mination of the projections, horse-chestnut shaped. Later, the 

 processes are withdrawn, the blood corpuscle becomes round, 

 and, at last, pale. In the corpuscles of the newt and frog the 

 effects are not dissimilar. They become wrinkled and dappled, 

 but these appearances are very transitory, and they are again 

 seen to be circular and pale, while the nucleus becomes round 

 and sharply defined. Not unfrequently it happens that one or 

 more blood corpuscles coalesce before they lose their color, or 

 that (in amphibian blood) the nucleus is discharged while the 

 disk is still yellow. The effects produced by induction cur- 

 rents are altogether analogous to those above described. Un- 

 der the action of the constant current (a single Bunsen's cell) 

 the corpuscles next the electrodes undergo changes, which at 

 the negative pole correspond to the action of an acid, at the 

 positive, to that of an alkali. In a salt preparation of batra- 

 chian blood examined near the positive pole, the nucleus comes 

 first into view, and then the corpuscles lose their color. In a 

 similar preparation of human blood in which the corpuscles 

 are horse-chestnut shaped already, they become smooth, lose 

 their color, and disappear. 



The colorless corpuscles, when excited electrically during 

 3 



