Journal of Applied Microscopy. 



367 



incomplete, crystals of corrosive sublimate will be unduly conspicuous in the 

 preparation. Camphor may be used instead of iodine to hasten the washing. 



The carmines are very brilliant after corrosive sublimate on account of the 

 formation of mercuric carminate, but haimatoxylin and anilines also give good 

 results. It is claimed, however, that achromatic structures do not stain well. It 

 might be worth while to test something besides the safranin-gentian violet-orange 

 combination before discarding this reagent for cytological work. 



Corrosive sublimate material gets very brittle if allowed to remain long in 

 alcohol, and therefore it is better to imbed it as soon as possible. 



FORMALIN. 

 Formalin is a comparatively recent addition to the list of killing and fixing 

 agents. It is an excellent preservative, often preserving the color as well as the 

 structure of objects. A 2 or 4 per cent, solution in water is good for filamentous 

 algae. The material may simply be put into the reagent, and left until needed for 

 use. After a thorough washing in water, any of the usual stains may be used. 

 Some good notes on formalin will be found in the Botanical Gazette of March, 

 1896. 



( To be Continued. ) 



A Convenient Washing Bottle. 



Perhaps the most important step in the preparation of objects for the com- 

 pleted mount is washing out the hardening fluid. 



A very simple piece of apparatus seems to accomplish this end most success- 

 fully. It consists of a large-mouthed bottle fitted with a two-hole stopper, two 

 short pieces of glass tubing, and, also, a piece of 

 rubber tubing for connections. The stopper should 

 fit tightly, so that the small particles which are being 

 washed cannot become lodged between the stopper 

 and the neck of the bottle. The two pieces of glass 

 tubing are bent and passed through the holes of the 

 stopper, as shown in the cut ; the one should reach 

 almost to the bottom of the bottle, while the other 

 should barely pass through the stopper. Before 

 placing the latter tube in position, put a piece of 

 cloth of coarse mesh, or perhaps some wool fibers, 

 over the end, to prevent the particles from being 

 driven out while they are being washed. 



The bottle is now ready for use. The objects 

 to be washed, with the hardening fluid, are poured 

 into the bottle, and water is allowed to flow through 

 as long as is necessary. If there is no hydrant at 

 hand, fill a large jar, or bottle, with water, raise it to a higher level than the washing 

 apparatus, connect the two, and allow the water to siphon off through the bottle. 



When the washing is completed, the objects can be poured into another ves- 

 sel, or they can be poured into a cloth, and from there transferred to the first- 

 grade alcohol. Sometimes the washed objects seem very soft; if such is the 

 case, it is better to carry them through the alcohols in the washing bottle. 



This is a very simple looking apparatus, but it will be found very convenient, 

 easy to make, and efficient in washing objects of all kinds where the hardening 

 fluid must be removed. Ernest I. Kizer. 



Purdue University. 



