550 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [6] 
under No. I and No. IT, whilst retting water, at the same temperature, 
showed a different percentage: 
Saale water. Retting water. 
it 10 
Oxy GON s jai. i. ss 2) LOS OMe 25.9 =1 4.2) =i 
JS FUG OY S01 Ae ee Gdn1-Qu ae, 57.6 CAR ATI Pe 
Carbonic acid ........... Bape 116.5 } =2. 86 | 65.9 } 22, = 
The proportion of oxygen to the other gases which can be expelled 
by boiling and which produce suffocation, has therefore been decreased 
ten fold. Taking finally into consideration the fact that 1,000 cubic 
centimeters retting water contained 64 cubic centimeters gases, whilst 
repeated experiments with river water showed that the same contained 
only 30.32 cubic centimeters, the fatal character of the mixture will be- 
come still more apparent in its relation to the breathing and life of fish. 
It cannot be doubted, therefore, that retting water will kill fish by 
its lack of oxygen, if from no other cause. In this all observations 
made on a large and small scale will agree. The fish immediately gasp 
for air until they become tired, and finally suffocate. Even leaving 
this hurtful mixture of gases out of our calculation, it must be granted 
that putrefying substances must exercise a hurtful influence, both di- 
rectly by producing changes which are injurious to life, and indirectly 
by rapidly absorbing oxygen and thereby depriving the surrounding 
objects of this gas which is so essential to all life. 
If only small quantities of retting water are mixed with large quanti- 
ties of running water there may be no immediate evil consequences, 
whilst if this proportion is reversed the injurious consequences will 
make themselves felt very soon; in either case, however, poisonous 
substances are introduced in the water which had better be kept out 
of it. 
The introduction of retting water into fishing waters should therefore 
be strictly prohibited, and has actually been prohibited in many places. 
The retting water may be employed much more suitably in irrigating 
meadows, where, owing to the loose soil, it loses its putrid character 
very soon, and aids in forming good food for plants. It would be still 
better if the moist method of retting could be altogether abandoned, 
and the dry method adopted in all cases, or if other and less injurious 
methods could be discovered and come into general use. 
