ZOOLOGY AND BOTANY, MICEOSCOPY, ETC. 847 



remain for 16, 24, 48 hours without becoming brittle, and only being 

 stained a yellowish-brown colour, except the myelin, which is almost 

 black, the medullated fibres and their endings are clearly seen. The 

 author says that he has had quite satisfactory results with Meissner's and 

 Grandry's corpuscles. The objects fixed by the foregoing solution should 

 be well soaked in water, and after-hardened in absolute alcohol. 



The author also gives the following procedure for treating con- 

 nective tissue formations with gold chloride. The objects are placed for 

 two, three, or more hours in a 1 per cent, chloride solution, acidulated 

 with hydrochloric acid (100 : 1). After having been washed they are 

 placed in the dark in a 1/50-1/100 per cent, solution of chromic acid 

 for reduction. Though reduction may not at this stage be perfect, it is 

 completed later on in oil of cloves, and the preparation is then mounted 

 in balsam. The more carefully the chromic acid is washed out the 

 clearer the picture is. The non-medullated nerve-fibres and their rami- 

 fications are stained almost black. The connective tissue cells appear 

 just as distinctly, while the intercellular substance of the connective 

 tissue is unstained. Muscle-fibres, striped and unstriped, are stained 

 a greenish-blue colour. The author states that this method is almost 

 always certain. 



Phenol in Microscopical Technique.* — When sections imbedded in 

 paraffin curl up and are placed in turpentine oil it is found extremely 

 difficult to flatten them without breaking them. This inconvenience, 

 says Signer E. Aievoli, may be remedied in the following manner : — the 

 sections are immersed for 15-30 minutes in benzin or turpentine oil, 

 and are then transferred to pure fluid phenol, wherein the sections unroll 

 themselves and come to the surface of the fluid. The carbolic acid does 

 not damage the tissue structure, even if the sections be left in it for 

 twenty-four hours. The sections are then treated in the usual manner. 



The author found great advantage in staining tissues en masse with 

 a carmine solution prepared in the following manner : — One grm. of 

 carmine is dissolved in 100 ccm. of hot water, and tlien 7 grm. of powdered 

 carbolate of soda are added. The solution is kept stirred for 30-40 

 minutes and filtered when cold. In this solution large pieces of tissue 

 may be stained in twenty-four hours. They are then transferred to 

 acidulated (1 per cent.) spirit for some hours. This method is stated to 

 give stronger and clearer colouring to the nuclei than other carmine 

 solutions. It is also especially suitable for tissues which have been 

 fixed with sublimate or absolute alcohol. 



Double Staining.f — Dr. J. H. List states that the double stains re- 

 commended by him for epithelia, glands, and cartilage have undergone 

 the test of time, the preparations retaining the beauty of the stain after 

 a lapse of four years. (For the original methods see this Journal, 1885, 

 p. 902.) In his present note the author mentions again eosin-methyl-green 

 for epithelium, glands, and cartilage, and h^matoxylin-eosin for glands 

 and retina. With this stain it is absolutely necessary that objects 

 hardened in acids should be thoroughly washed to remove all traces of 

 the acid, otherwise a precipitate may form on the preparation. 



Bismarck brown (Weigert's formula) gave excellent results with 

 Invertebrates (connective tissue of molluscs), and rosanilin nitrate was 



* Kivista Internaz. Med. e Chirurg. Napoli, iv. pp. 101-4. 

 t Zeitschr. f. Wiss. Mikr., v. (1888) pp. 53-4. 



