In one litre (1,000 cubic centimetres).
| Nitric acid anhydride, N₂O₅. | 10.72 | milligrammes |
| Ammonia, NH₃, | 0.03 | ” |
| Carbonic acid anhydride, CO₂. | 0.439 | gramme. |
| Calcium oxide, CaO, | 0.148 | ” |
| Magnesium oxide, MgO, | 0.04128 | ” |
| Chlorine, | 0.09218 | ” |
| Degree of hardness (English) | 25.7 |
The organic matter in 100 cubic centimetres of the water required 3.11 cubic centimetres of the 1-100 normal solution of potassium permanganate to oxidize it; therefore one litre of the water would require 31.1 cubic centimetres of the 1-100 normal solution KMnO₄ to oxidize the organic matter. In 31.1 c. c. of this solution there is 0.0098 gramme KMnO₄ or 0.0247 gramme oxygen liberated. I would remark here that there is no method of estimating the exact quantity of organic matter in water. The method of estimating the carbon and hydrogen by combustion analysis (Frankland and Armstrong’s) has been found defective,—also the methods based on the estimation of nitrogen and reduction of silver oxide. The method employed in this case (Schultze’s) is the most reliable, and yet not all the organic matter is oxidized, for some is volatized in boiling.
I found the following infusorial animalaculcæ: Stylonchia pustulata, actinurus neptunius, rotirfer vulgaris, monostylaquadridentata, navicular baltica.
I give here the magnified pictures.
Actinurus Neptunius.
Navicula Baltica.