714 SUMMARY OF CURRENT RESEARCHES RELATING" TO 



tubercle bacillus stain (dilute), and leave for twelve bours, remove to a 

 slij) containing alcobol of 20°; replace latter by alcobol of 50°, and 

 fiually of 90°; clear, and fix witb clove-oil collodion and mount in 

 Canada balsam. If it is not desired to mount tbe object at once, it can 

 be placed in saturated alum water after removal of tbe glycerin, after- 

 wards stained witb b^matoxylin and mounted in any way desired. 



Wbere caustic potasb bas been used as tbe isolating material tbe 

 latter may be neutralized by tbe use of a 60 per cent, solution of acetate 

 of potassium. Tbere sbould be a plentiful supply of tbe neutralizing 

 agent used, changing tbe cbarge two or tbree times. After pouring it 

 olf for tbe last time, wasb witb plenty of a saturated aqueous solution of 

 alum, stain witb alum carmine, or baematoxylin, and mount as desired. 



Staining the Walls of Yeast-plant Cells.*— In demonstrating tbe 

 two membranes of tbe cell of tbe yeast-plant, Prof. S. H. Yines found tbat, 

 by first staining tbe cells in metbyl-violet, washing in distilled water, 

 and then transferring to anilin-green for some hours, in some instances 

 tbe inner membrane appears of a violet colour, while the outer layer 

 takes a slight green. 



Solubility of Fat and Myelin in Turpentine Oil after the action 

 of Osmic Acid.f — Prof. W. Flemming states that fat having been 

 blackened witb pure osmic acid never loses colour, even though exposed 

 to direct sunlijiht for hours and afterwards treated with turpentine. This 

 statement is made in consequence of a communication of M. C. Dekhuyzen, 

 who found that preparations treated with Flemming's chrom-osmium- 

 acetic acid mixture became decolorized when treated with turpentine oil 

 or turpentine balsam. M. C. Dekhuyzen's explanation of the action is 

 that turpentine oil acquires oxydizing properties by exposure to direct 

 sunlight. This may or not be, but if the author's observations are 

 correct it is obvious that the decoloration must be due to the association 

 of the acetic or chromic acid. 



Cole's (A. 0.) New Slides. 



["New method of staining tissues, and particularly nervous structures. This 

 method is strikingly brought out by the slide showing sections of the lumbar 

 and dor.-^al region of the human spinal cord in four colours. This new stain 

 is particularly elfective for photomicrography, as is proved l^y another slide 

 mounting a transverse section of the left median human nerve. The other 

 slides, mounted with the new staining, are very interesting : — Transverse 

 section through the spinal cord and stomach of a snake, showing a semi- 

 devoured lizard, and also section of the lizard's spinal cord ; section through 

 tlie cervical region of snake, showing spinal cord, oesophagus, &c. ; and an 

 effective mount (for microscopic purposes), giving vertical and horizontal 

 sections of the human scalp, showing the hair-follicles, &c."] 



Sci.-Gossip, 1889, p. 184. 



Staining Tuhercle-Bacilli. Journ. of Microscopy, II. (1889) pp. 165-6, 



from ' National Druggist.' 



(5) Mounting-, including Slides, Preservative Fluids, &c. 



Hints on Mounting Objects in Farrant's Medium. | — Mr. C. M. 



Vorce writes : — Attention is being turned again to this old but too much 

 neglected medium, the preparation of which by all the published formulae 

 is attended witb much trouble and vexation. The chief difficulty is in 



* Journ. of Microscopy, 1888, p. 12. 



t Zeitschr. f. Wiss. Mikr., vi. (1889) pp. 39-40. 



X Amer. Mon. Micr. Journ., x. (1889) pp. 149-50. 



