222 APPENDIX. 



diluted to 8(% 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. 



Acetic Acid and Methyl-green. This is valuable for staining 

 nuclei in vegetal tissues. Dissolve methyl-green in one or two 

 per cent acetic acid until a rich deep color is obtained. 



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 24 hours. After staining 

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

 tions) 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 (1030 m.). Afterwards remove to 70$ 

 alcohol. 



Canada Balsam, Mounting in. This invaluable substance may 

 be 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 ob- 

 tained from most of the dealers. The principles of mounting in 

 balsam are very simple. It does not mix with water or alcohol, 

 but mixes freely with clove-oil, chloroform, benzole, etc. Ob- 

 jects are therefore generally treated, first with very strong alco- 

 hol, 95-100$, 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 inverted over the object. 

 The balsam gradually sets and the preparations are 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 experiments with cilia, etc. 



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

 Borax- carmine.) 



Cellulose- test. Saturate the object in iodine solution, wash in 

 water, and place it in strong sulphuric acid prepared by carefully 

 pouring 2 volumes of the concentrated acid into 1 volume of 

 water. 



