and Laboratory Methods. 2123 



MATERIAL. 



Under the Exterior of the Buildiag, the subject of material is naturally 

 included. Material used in the construction of a museum is determined by 

 financial resources, taste, and convenience. Marble, or marble and brick, gray 

 limestones and brick, brick alone, gray or white granites with brick, red granite 

 alone or with brick, buff or white furnish a range of combinations and effects 

 where the means for building are adequate for such indulgence. 



A word of preference may be included. The combination of two materials 

 of contrasted color, if adroitly used, produces more refined effects than a single 

 stone, unless an exception be made in favor of marble. 



Generally speaking, there should be but one entrance, unless this may be 

 combined with one exit. As an entrance contains bulletin boards, announce- 

 ments, and possibly publications, it is desirable to avoid their duplication at a 

 number of points. One entrance also ensures a very correct review of the 

 attendance and its character. 



Thickness of walls and all possible safeguards against dampness should be 

 provided for. Discoloration of walls entails expensive replastering, and as 

 repairs in museums are often vexatious and delayed, the best provisions can be 

 made at the outset for their prevention. 

 American Museum of Natural History. L P. Gratacap. 



A Review of the Methods of Staining Blood. 



IV. 



C. Double Staining with Acid and Basic Stains — Continued. 



4. Eosin and Methylen Blue. — Chenzinsky's (1S89) eosin and methylen 

 blue solution is as follows : A concentrated watery solution of methylen blue, 

 diluted one-half with water, is mixed with an equal volume of a one-half per cent, 

 solution of eosin in 60 per cent, alcohol. Fixed dry blood preparations are 

 stained four to five minutes in this solution, then washed, dried, and mounted. 



PleJui (1S90) gives the following formula: 



Concentrated watery solution of methylen blue, 60 

 One-half per cent, solution of eosin in 75 per 



cent, alcohol, ------ 20 



Distilled water, ------ 40 



Twenty per cent, potassic hydrate, - - 12 drops. 



Fix dry preparations in absolute alcohol for from three to five minutes, stain 

 five or six minutes, wash in water, dry, and mount. 



Aldehoff (1891) stained blood preparations with a concentrated alcoholic 

 solution of eosin [Nr. 22 (blaulich) ; Fabrik Bayer in Elberfield] for one-half 

 hour cold, or two to three minutes hot, washed and stained a very short time in 

 a concentrated watery solution of methylen blue, then washed, dried, and 

 mounted. 



Laveran (1S91) recommends the following procedure in successive stain- 



