BY DR. KLEIN. 29 



with salt solution, the naturally bi concave colored corpuscles 

 exhibit a remarkable alteration, which consists in thuir assum- 

 ing a form very similar to that of the fruit of the horse-chest- 

 nut. In those corpuscles which present their surfaces, the 

 processes which project from the margin look like the rays of 

 a star, while those which spring from the surface appear as 

 dark points. In such a preparation it is not difficult to float 

 away the colored disks altogether, by irrigating it immedi- 

 ately with salt solution. The colorless corpuscles sink very 

 rapidly, and stick to the glass, while the colored disks remain 

 suspended. 



Let us seek for a field in which one or two colorless corpus- 

 cles only are to be seen. By discontinuing the irrigation, at 

 the same time replacing the bit of blotting-paper so as to with- 

 draw the fluid, we bring the cover so near the slide that it 

 compresses the corpuscles, which in consequence appear paler 

 and larger. The paper is now taken away, and salt solution 

 added at the opposite edge as before. The corpuscles at once 

 become smaller and more globular, and seem to contract; but, 

 immediately after, dilate again, as if they were relaxing. In 

 the resumption by the corpuscle of its original form after 

 compression, we have to do with a phenomenon which can only 

 be explained on the supposition that the colorless corpuscle is 

 elastic. The nature of the contraction and the subsequent re- 

 laxation lead us, however, to suppose that the contraction is, 

 at least partly, a result of the excitation produced by the irri- 

 gation with saline solution. 



Action of Water on Mammalian Blood. As regards 

 the action of water on the corpuscles of mammalian blood, 

 there is not much to be added to what has been said with re- 

 ference to newt's blood ; the colorless corpuscles discontinue 

 their movements, become globular in form, exhibit vesicular 

 nuclei and vibrating granules, and finally are disintegrated. 

 The colored disks lose their horse-chestnut form, become 

 smooth and pale, and eventually disappear. 



Action of Acids. The general action of acids is so uni- 

 form that it is not necessary to refer separately to each. We 

 content ourselves with describing the action of acetic acid. A 

 special action of boracic acid will be noticed further on. The 

 final result of the action of acetic acid on the blood corpuscles 

 is the same, whether i", is diluted or concentrated. The rapid- 

 it}' with which the changes take place is, however, different. It 

 is always better to begin with dilute acid. If a , salt solution 

 preparation of newt's blood is, after the shrinking of the colored 

 corpuscles, irrigated with a liquid containing one per cent, of 

 the ordinary commercial acid, we observe, first, that the move- 

 ments of the colorless corpuscles cease, and that they enlarge 

 and display their nuclei as sharply-defined bodies, beset with 



