702 SUMMARY OF CURRENT RESEARCHES RELATING TO 



The fluids themselves, whose use the author describes, are already 

 known ; the new matter in his present communication is the account 

 of the modes in which he finds they can be most advantageously 

 used. 



Bichloride of mercury, or corrosive sublimate, is the principal 

 basis of the solutions. Combining with the histological elements, 

 both animal and vegetable, it renders them insoluble, so that they can 

 be preserved indefinitely in an aqueous medium. But, as the 

 bichloride of mercury coagulates and precipitates the albuminous 

 matter that exists in the interstitial fluids of the tissues, to prevent 

 this coagulation salt is associated with it for certain preparations, and 

 acetic acid for others, and in more or less considerable quantities, 

 according to the effects to be obtained. 



Parts. 



I. Bichloride of mercury 1 



Distilled water 200 



II. Bichloride of mercury 1 



Commou salt 2 



Distilled water .. 200 



III. Bichloride of mercury 1 



Common salt 4 



Distilled water .. .. 200 



IV. Bichloride of mercury 1 



Acetic acid 2 



Distilled water .. ., . 300 



No. I. is of limited use, but will preserve indefinitely all histo- 

 logical substances, both animal and vegetable, which are solid and 

 non-albuminous, for hollow substances either swell or become too 

 opaque by the coagulation of the albumen. It can, however, generally 

 be substituted for the other solutions when it is desirable to entirely 

 remove the salt or acetic acid from the solution in which any given 

 preparation has been placed. 



No. II. may be generally employed for all tissues both cellular and 

 fibrous, animal or vegetable, provided they are sufficiently dissociated 

 in sections of extreme thinness, because they become somewhat 

 opaque, regaining, however, in time a certain transparency. It is 

 especially useful for the blood-corpuscles of cold-blooded animals 

 having a less density than III. 



No. III. serves specially for the blood-corpuscles of warm-blooded 

 animals. 



No. IV. serves best for the nuclei of animal tissues, but it swells 

 up the fibres and distorts the forms of the cells. Still, in certain 

 cases it is very useful, and it preserves the white blood-corpuscles 

 admirably. 



All the solutions should be employed in sufficiently large quan- 

 tities, and the specimen kept in it for 4-5 clays or longer, in order 

 that it may have time to take up a sufficient quantity of the bichloride 

 of mercury before being finally closed up. 



