Formulae for Reagents 307 



AMOUNTS OF REAGENTS REQUIRED 



It is difficult to estimate the amounts of the various reagents 

 needed by a class in histology. Two dangers must be guarded 

 against wastefulness and too great economy; for economy in some 

 reagents, like absolute alcohol, turpentine, xylol, and clove oil, may 

 be so rigid as to make the preparations decidedly inferior. 



Each student should have some reagents upon his own table. 

 The following is an estimate of the amounts of some reagents used 

 by each student in a three-months' course in method: commercial 

 alcohol (about 95 per cent), 3 liters; absolute alcohol, 800 c.c.; 

 turpentine (for dissolving paraffin ribbons), 200 c.c.; xylol, 400 c.c.; 

 clove oil, 75c.c.; Canada balsam, 25 c.c.; hard and soft paraffin, 

 400 g. each; safranin, gentian-violet, orange, cyanin, erythrosin, 

 Delafield's haematoxylin, iron-haematoxylin, and ammonia sulphate 

 of iron (3 per cent), 100 c.c. each. 



For general use of the entire class, other stains and reagents may 

 be kept upon a table accessible to all. Some stains which act very 

 rapidly, like cyanin, erythrosin, and orange, may be kept upon the 

 common table. A class of ten will use about 20 liters of the stock 

 solution of chromo-acetic acid, and of glacial acetic acid about 

 400c.c.; commercial formalin, about 200 c.c.; Venetian turpentine, 

 500c.c.; cedar oil, 200 c.c.; Eycleshymer's clearing fluid, 100 c.c.; 

 glycerin, 600 c.c.; chloroform, 100 c.c.; ether-alcohol, 200 c.c.; 

 celloidin, 40 g.; hydrochloric acid, 200 c.c.; nitric acid and sulphuric 

 acid, 50 c.c. each; Magdala red and methyl green, 200 c.c. each; 

 other stains, 100 c.c. each. 



No attempt has been made to make the foregoing list absolutely 

 complete. The equipment of any laboratory will be built up gradu- 

 ally. When the microtome needs oiling, some sewing-machine oil 

 may be added to the general equipment. It is hoped that reagents 

 omitted from the list are, like the sewing-machine oil, readily secured 

 without vexatious delays. 



