APPENDIX 597 
N/10 Potassium Permanganate. Dissolve 3.163 gms in a liter of 
water and standardize against ferrous ammonium sulphate, oxalic acid 
or pure iron. 
1 c.c. =.0056 gm. Fe 1 c.c.= .0008 gm. O. 
.0072 gm. FeO .0063 gm. HeC404.2H20. 
.008 gm. Fe2Qs. 
N/10 Iodine. Dissolve 12.685 or 12.8 gms. of pure iodine and 18 
gms. of potassium iodide in a liter of distilled water. Standardize 
against N/10 Na2SeQs3. 
L ¢.c. 
I 
0158 gm. Na2Se0s, 
.00495 gm. AseOs, 
.00575 gm. AseQOs. 
N/10 Sodium Thiosulphate. Dissolve 24.9 gm. of the crystals in 
1000 c.c. of water and standardize against N/10 iodine. 
N/10 Sodium Chloride. Dissolve 5.9 of the salt in 1000 c.c. of water. 
Standardize gravimetrically by precipitating as AgCl. 
1 c.c. = .0058 gm. NaCl, 
.0035 gm. Cl, 
.0108 gm. Ag. 
N/10 Silver Nitrate. Dissolve 16.966 gms. of AgNQg3 in a liter of 
water and standardize by precipitating as AgCl. The preparation of 
standard silver nitrate for water analysis is outlined in another place. 
Preparation of Antiformin. Dissolve 720 gms. of chloride of lime 
and 260 gms. of sodium carbonate in 2500 c.c. of water. Allow to stand 
and filter. By means of N/10 sodium thiosulphate determine the 
amount of available chlorine and adjust so that it will contain about 
5.6 per cent. Add 7.5 per cent of sodium hydroxide, filter and store for 
future use. 
Azolitmin Solution. Add 1 per cent of Kahlbaum’s azolitmin to 
distilled water and boil for five minutes. Adjust the reaction, if 
necessary, with NaOH. It should give a distinct blue plate when it is 
diluted in the Petri dish with the medium. 
Benedict’s Reagent for the Quantitative Estimation of Dextrose. 
l 
I 
i 
Copper sulphate (crystallized)............ 18.00 gms. 
Sodium carbonate (anhydrous)............ 100.00 gms. 
Sodium citrate... 2.0... 00... 2 cece eee eee 200.00 gms. 
Potassium thiocyanate................... 125.00 gms. 
Potassium ferrocyanide (5 per cent solution). 5.00 c.e. 
Distilled water to make 1 liter. 
