* 
, 
«{ 
ih 
548 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [4] 
interruptedly for air, and were found dead the next morning. The ex- 
periment had commenced towards evening of the preceding day. 
The second experiment, made the following day in exactly the same 
manner, led to exactly the same result. The fish died within three 
hours. 
One of the large bastard carp lived in this mixture of fresh water and 
retting water for two days, but soon began to lose its color, gradually 
grew weaker, and, although again placed in running water, died after 
eight days. 
One part retting water and nine parts running water mixed.—The fish 
immediately began to be sick, showing this by their motions and their 
gasping for air; lived for twenty-four hours in the mixture, and began 
to recover when again placed in fresh running water, but finally died 
after a few days. 
One part retting water and two parts running water.—Small fish died 
very soon. A large bastard carp kept alive for one and three-fourths 
days, but was on the point of death when at that period again trans- 
ferred to pure running water, from which time it began to recover, but 
only to die within two weeks. 
Retting water fourteen days old.—In a mixture of one part of this ret- 
ting water and four parts fresh water the fish died after one and one- 
half days. 
The same retting water three weeks old.—Fish placed in it (one part ret- 
ting water and four parts fresh water) grew sick immediately, gasped 
for air and changed their color, but managed to keep alive for several 
days, so that they could again be transferred to fresh running water. 
As all these experiments led to the same expected result, they were 
brought to a close. The conclusion was as follows: 
hetting water, when in a putrid condition, kills fish within a few hours, 
even when mixed with three to four parts of running water which is 
otherwise well adapted to pisciculture. When mixed with a larger pro- 
portion of fresh water the fish can stand it better, but are nevertheless 
considerably injured. 
Retting water which is allowed to stand for some time, and which 
thereby loses its strongly putrid character, does not therefore hurt the 
fish so much. 
These experiments fully corroborate the facts observed in rivers on 
a larger scale. Wherever actually putrid retting water mingles with 
pure water, a poisonous juice, which is positively injurious to fish, exists 
in the water, and shows its destructive character in proportion to the 
degree of putrefaction and its quantity. 
I was not able to obtain water in which hemp had been retted; in 
such water one might have looked for positive vegetable poisons, as such 
substances have been shown to exist in hemp. Repeated experiments 
with water in which I had laid hemp and allowed it to putrefy did not 
show any substances of an alkaloid or acid nature in the water. The 
