252 ELEMENTS OF BOTANY. 
Assorted corks and rubber stoppers. 
Microscope slides. 
Thin glass covers. 
Thin sheet rubber, such as is used by dentists, in pieces about 24 
inches square (this is not needed if the teacher prefers to use sheet 
lead in the transpiration experiment; see page 115). : 
General Reagents and other Supplies. — Alcohol, commercial, 95%. 
Alcohol, absolute, a few ounces only. 
Hematoxylin solution.} 
Canada balsam. 
Caustic potash solution, one part of solid caustic potash in 20 
parts distilled water. 
Nitric acid, concentrated. 
Red ink.? 
Potassium chlorate. 
Fehling’s solution, test for grape sugar. This reagent may best 
be bought of the wholesale druggist or dealer in chemicals. It may 
be prepared by dissolving 34.64 grams pure crystallized cupric 
sulphate in 200 cubic centimeters water and mixing the solution 
with 150 grams neutral potassic tartrate, dissolved in about 500 
cubic centimeters of a 10-per-cent solution of sodium hydrate. The 
whole is then to be diluted with water to 1 litre and 100 cubic centi- 
meters glycerine added. | 
Millon’s reagent for proteids. Prepared by dissolving 1 part by 
weight of mercury in 2 parts of nitric acid of sp. gr. 1.42 and then 
diluting with twice its volume of water. . 
Preservative fluid, prepared by dissolving 20 parts by weight of 
chrome alum and 5 parts formalin in 975 parts of water. This 
serves to preserve (although it may discolor) portions of leaves, 
stems, rootstocks, roots, fruits, etc., which it is desirable to keep in 
a moist condition, and is much cheaper than alcohol. One part 
formalin to 40 of water by volume makes a still better preservative 
1 Tt is cheaper to buy this than to make it. 
~ 2 As considerable quantities of this are to be used (especially if it is issued to the 
class for home work), if it cannot be bought very cheaply the instructor may make it 
for himself by dissolving eosin in water. Eosin costs by the pound from $1.65 to 
$2. An ounce will make as much as two quarts of red ink. 
