716 SUMMARY OF CURRENT RESEARCHES RELATING TO 



succeeds best with chromic acid), the above process is to be preferred 

 to all others. The only alternative method is hematoxylin, and 

 that is much more uncertain in its action. 



Iodine-green for Human and Animal Tissues.* — Dr. H. Gries- 

 bach recommends as the most useful of all anilin staining materials for 

 this purpose, a new green material, tetramethylrosanilinmethyliodide, 

 or " iodine green," or " Hofmann's green." The composition of the 

 solution for staining is preferably • 1 gr. crystallized iodine green, 

 and 35 gr. distilled water, though it may be varied according to the 

 tint required. The hardened tissue is placed for a few seconds in 

 distilled water and then in the staining fluid, the action being almost 

 momentary. After washing in distilled water it is transferred to 

 glycerine or absolute alcohol, cleared in oil of cloves or aniseed, and 

 mounted in Canada balsam or dammar. 



The objection to other anilin colours, that alcohol often draws the 

 colour completely out in a few minutes, scarcely applies to iodine 

 green, which is much more resistant. Its chief advantages, however, 

 are its rapid action, which adapts it excellently for demonstrations, 

 and the fact that it also often gives different tints of the same colour 

 to different parts of the tissues. For instance in a section of the 

 uterus of a deer, the epithelium is blue, the tubular glands dark 

 green, the cylindrical ciliated cells of the single tubes show a 

 splendid colouring of their nuclei, the longitudinal musculature is 

 malachite green, and the connective tissue remains uncoloured. 

 Hardened objects colour better than fresh. Connective tissues and 

 bones are not coloured at all or only very slightly. Glandular organs, 

 hardened in alcohol, are excellent objects. The gland-cells are dis- 

 tinguished from the membrana propria by an intense and uniform 

 colour. Striated muscle (in alcohol preparations) is coloured a 

 cantharides green, the sarcolemma remaining uncoloured. Iodine 

 green is also very useful for blood-corpuscles of vertebrates and 

 invertebrates, for human white blood-corpuscles, and all kinds of 

 isolated cells, spermatozoids, bacteria, &c. Also for ganglion-cells 

 and axis-cylinder. In a section through human spinal cord in a 

 chromic acid preparation (after a brief treatment with absolute 

 alcohol and rinsing in distilled water) the horns of the grey substance 

 were immediately coloured a uniform green, the substantia gelatinosa 

 the same but brighter, the substantia alba being uncoloured. This is 

 an additional advantage of iodine green as it is well known with 

 what difficulty chromic acid preparations take certain colours. 



Professor Kollmann's statement of his satisfactory experiences 

 with iodine green is added. 



Teichmann's Injection-mass.f — The exact proportions of the 

 materials used by L. Teichmann for his injection-mass J are as 

 follows : — 



Bed mass: — Prepared chalk 5 gr., vermilion 1 gr., linseed oil 



* Zool. Anzeig., v. (1882) pp. 406-10. 



t Abh. and SB. Naturw. Kl. Akad. Krakau, vii. (1880) pp. 108. Cf. 

 Jaliresber. Anat. u. Physiol., ix. (1881) pp. 11-12. 

 j Described generally in this Journal, ante, p. 125. 



