182 APPENDIX. 



.supplied and freely used. Alcohol of 100, i.e., " absolute" alcohol, 

 may be purchased in 1-pound bottles. " Squib b's " absolute 

 .alcohol may be obtained of any druggist,* but ordinary alcohol of 

 '90-95$ answers nearly every purpose. " Cologne spirits, "i.e., alco- 

 hol of about 94 , may be obtained from the makers at 60c., or there- 

 abouts, per gallon. This may then be diluted to 80$, 70$?, 50#, etc., 

 as needed. For this purpose an alcoholimeter is very convenient. 



Acetic Acid. One or two parts glacial acetic acid to 100 parts 

 water. 



Aniline Blue. Dissolve the powder in distilled water. It is best 

 to dilute the solution largely when used. 



Aniline Chloride. A saturated aqueous solution slightly acidu- 

 lated with hydrochloric acid. Turns lignified cell-walls bright 

 yellow (test for lignin). 



Borax-carmine. Add to a 4 aqueous solution of borax 2-3 

 carmine, and heat until the carmine dissolves. Add an equal 

 volume of 70$ alcohol, and filter after standing 24 hours. After 

 staining (6-12 hours, or more for large objects; a few minutes for 

 sections) place the object in acidulated alcohol (100 c.c. 35$ alcohol, 

 3-4 drops hydrochloric acid) and leave until the color turns from 

 dull to bright red (10-30 m. ). Afterwards remove to 70 alcohol. 



Canada Balsam, Mounting in. This in valuable substance maybe 

 obtained in the crude condition, dried by prolonged heating, and 

 then dissolved in chloroform, benzole, or turpentine, for use. The 

 benzole solution is perhaps the best, and may be obtained from most 

 of the dealers. The principles of mounting in balsam are very sim- 

 ple. It does not mix with water or alcohol, but mixes freely with 

 clove-oil, chloroform, benzole, etc. Objects are therefore generally 

 treated, first with very strong alcohol, 95-1002, in order to remove 

 the water; then with clove-oil, chloroform, or turpentine to remove 

 the alcohol, and afterwards mounted in a drop of balsam. This 

 should usually be placed on the cover-glass, which is thereupon in- 

 verted over the object. The balsam gradually sets firmly and the 

 preparations may be permanently preserved. 



Carmine. Carmine may be obtained as a powder, which when 

 rubbed up thoroughly with water in a mortar passes into a state of 

 very fine subdivision. This property makes it available for experi- 

 ments with cilia, etc. 



It is more often used in solution, as a staining agent. (See 

 Borax-carmine.) 



*Sec also Whitman, 1. c., p. 14. 



