112 THE AMERICAN MONTHLY [June, 



The author also recommends this latter method for staining sections of the 

 central nervous system, that have been hardened in solutions of chroine salts, 

 whereby the same elements are stained as\vith Weigert's htematoxvlin or acid 

 fuchsin. , 



o 



Methods of Examining Motor Nerve Endings.* W. Kiihne. — The 

 author recommends the following methods as giving the best results: — 



1. Lowit's gold method, with the subsequent treatment of the tissues with 

 the strongest formic acid. Especially useful for unfibrillated muscle. 



2. Soaking the tissues in ^% solution of formic acid, then in !%• solution 

 of auric chloride, reduction, in the dark, in a mixture of glycerine and water, 

 equal parts, with the addition of ;^ to ^ its volume of formic acid. Useful for 

 muscles of warm-blooded animals. 



3. The same as 3, without the previous soaking in formic acid. Useful 

 for cold-blooded animals. 



4. Golgi's method. Soak in a ^% solution of arsenic acid, then in auric 

 and potassium chloride, reducing in a 1% solution of arsenic acid in the sun- 

 light. Useful for all objects. 



5. An alteration of 4. The muscle strips are placed in a mixture of ^% 

 arsenic acid, ^% of auric and potassium chloride. 0.1% of osmic acid. Then 

 in 1% solution of arsenic acid. Reduce in the sunlight. Best for the reptilien 

 tissues. 



A Modification of the Usual Methods of Studying Nerve End- 

 ings with Auric Chloride and its Employment on the Muscles of 

 the Frog.t G. Boccardi. — The muscles are first treated with lemon juice 

 after the manner of Ranvier, then with auric chloride, or a mixture of auric 

 chloride and formic acid, then washed in water and placed in a ;|- to 1% solu- 

 tion of oxalic acid for two hours, or, what is better, in the following mixture : 

 Formic acid 5 c.c, i."o solution of oxalic acid i c.c, water 25 c.c, then 

 wash in water and mount in glvcerine. 



A New Method for Microscopical Examination of Blood. | D. 

 Biondet. — Not more than two drops of blood are allowed to fall into 5 c.c. 

 of a 2 per cent, solution of osmic acid, contained in a small glass cylinder. 

 The solution of osmic acid is to be filtered before use, to remove all granules, 

 etc. The acid is allowed to act tor twenty-four hours in the dark. At the 

 end of this time, four or five drops, of the mixture of blood and osmic acid 

 are removed with a pipette and added to a test tube of agar agar, which melts 

 at a temperature of 35° to 37° C, the tube is well shaken, and the contents 

 poured into a small pa^^er box. When the agar agar has become solid, the 

 paper is removed and the agar block placed in 85 percent, alcohol to harden. 

 The agar agar imbedding may be combined with paraffin as follows : — The 

 agar block is removed from the alcohol and placed in oil of bergamot for 

 twent3f-four hours, then direct in paraffin, melted at a temperature of 45° C. 

 for one to two hovn^s ; finally imbed in a paper box. 



Thin sections are made, with a microtome, from these blocks, stained in 

 the usual manner and mounted in balsam. The paraffin is removed from 

 the sections, before staining, with any of the usual solvents. 



*Zeitsch. f, Biol, xxiii, N. F., V., 1887, p. i. 



t Lavoii eseguiti nell' 1st, fisiol. di Napoli Fasc. i, 1886, p. 27. 



t Arch. f. Mikros., Anat. xxxi, p. 103, 1887. 



