182 APPENDIX 



Solution B 



Copper sulphate (CUSO4) 17.3 gm. 



Distilled water 100.0 c.e. 



Dissolve and make up to 150 c.c. with distilled water. 



Add B to A slowly with constant stirring. Keeps well. Gives 



a greenish-yellow precipitate (cuprous oxide) when heated 



with a solution of a reducing sugar. 



6. Fehling's solution 



Solution A 



Copper sulphate (CUSO4) 35 gm. 



Distilled water 500 c.c. 



Solution B 



Sodium hydroxide (NaOH) 160 gm. 



Potassium sodium tartrate (KNaC4H40(;) 173 gm. 



Distilled water 500 c.c. 



Mix equal parts of A and B shortly before using. When 



heated with an equal amount of a reducing sugar, gives a 



brick-red precipitate (cuprous oxide). 



7. Formalin solution (for preserving material) 



Dilute stock formalin, which is a saturated solution (40%) of 

 formaldehyde gas in water, to make 5 or 6 parts of this 

 40% solution in 100 parts of water. This is what is com- 

 monly meant by 5 or 6% formalin. 



8. Iodine solution (for starch test) 



Distilled water 100.0 c.c. 



Potassium iodide 0.7 gm. 



Iodine crystals 1.0 gm. 



9. Locke's solution (for mammalian tissues) 



Distilled water 1000.00 c.c. 



Sodium chloride (NaCl) 9.00 gm. 



Potassium chloride (KCl) 0.42 gm. 



Calcium chloride (CaCh,) 0.24 gm. 



Sodium carbonate (NaHCO....) 0.20 gm. 



Glucose 1.0-2.5 gm. 



The glucose need not be added unless the tissue is to be kept 

 alive for several hours. 



