(or multiples thereof) of the stock solution equal to the strength 

 solution desired and adding enough distilled water to make the total 

 number of milliliters equal to the strength of the stock solution. 

 Examples, (a) to prepare 7.1% from 18% stock solution use 7.1 ml. of 

 the stock plus 10.9 ml. of water which makes a total of 18 ml. (b) to 

 obtain a 0.02% solution from a 0.4% stock solution use 1 ml. of stock 

 (50 X 0.02) and 19 ml. of water (50 x 0.38) making 20 ml. (50 x 0.02 + 

 50 X 0.38) = (50 X 0.4) of the required solution. 



In general, remember that in diluting solutions the volume of the 

 concentrated solution times its concentration is equal to the volume 

 of the dilute solution times its concentration, or 



Vol. X Conc.= Volj,x Cone- 

 To make a 3/8 M solution from a IM solution, take three parts of the 

 IM solution and dilute to eight parts. For example, to make 500 ml. 

 of a 3/8 M solution of NaCl from a IM solution take 3/8 of 500 or 

 186.5 ml. of IM NaCl and dilute to 500 ml. To make 50 ml. of a 

 1:10,000 solution requires 1:10,000 of 50 or 0.005 grams of the active 

 ingredient made to 50 ml. with water. 



PROOF is the scale used for measuring the strength of alcohol. 

 Absolute alcohol is 200 proof; and a mixture containing 50% alcohol 

 by volume is 100 proof (U.S.A.) 



A proof-gallon contains an amount of alcohol equal to that in 

 a gallon of proof spirit (100 proof). A gallon of proof spirit is 

 one-half alcohol. Wine gallons multiplied by 1.9 equals proof gallons, 



DELIQUESCENT CHEMICALS. Bottle tops of the following chemicals 

 should be dipped in paraffin. 



Acetamide 

 Acid arsenic 

 Acid chromic 

 Ac id citric 

 Acid monochloracet ic 

 Acid s i 1 icotungst ic 

 Acid trichloracetic 

 Aluminum chloride 

 Aluminum nitrate 

 Ammonium acetate 

 Ammonium fluoride 

 Ammonium thiocyanate 

 Barium bromide 

 Barium chloride 

 Beryllium chloride 

 Beryllium nitrate 



Beryllium sulfate 

 Calcium bromide 

 Calcium chlorate 

 Calcium chloride, 

 Calcium chloride, 

 Calcium nitrate 

 Calcium oxide 

 Cobalt sulfate 

 Ferric chloride 

 Ferric nitrate 

 Ferrous chloride 

 Iodides (most forms) 

 Lithium bromide 

 Lithium chloride 

 Lithium salicylate 

 Magnesium bromide 



Magnesium chloride 

 Magnesium nitrate 

 Manganese chloride 

 anhyd Manganese sulfate 

 cryst Mercuric nitrate 

 Potassium acetate 

 Potassium carbonate 

 Potassium thiocyanate 

 Sodium arsenate, cryst 

 Sodium chlorate 

 Sodium hypophosphite 

 Sodium selenate 

 Sodium sulfide 

 Sodium sulfite, anhyd. 

 Sodium thiocyanate 

 Starch 

 Zinc chloride 



-5- 



