397 



Kriss does not share the opinion of P. Danilchenko and N. Chigirin (1926) 

 that a reduction of sulphates by organic carbon is also indicated by a com- 

 parison of the distribution of calcium and carbonates with that of hydrogen 

 sulphide. Thus Kriss has reason to doubt Danilchenko and Chigirin's sug- 

 gestion that ' hydrogen sulphide in the Black Sea results from the reduction of 

 sulphates by the carbon of organic substances through the formation of inter- 

 mediate products down to sulphides, and the decomposition of the latter by 

 carbonic acid and bicarbonates with the evolution of hydrogen sulphide'. 

 Without questioning this idea Kriss agrees with the opinion of Andrussov, 

 expressed earlier, that the hydrogen sulphide in the Black Sea 'is the sum 

 total of hydrogen sulphide developed during the putrefaction of organic 

 matter . . . plus the hydrogen sulphide formed as a final result of the reduction 

 of sulphates'. 



Moreover S. Brujevitch (1953), the authority on this question, says that an 

 examination of all the data on hydrogen sulphide fermentation in the Black 

 Sea 'leaves no doubt that in the main mass hydrogen sulphide is the result of 

 sulphate reduction, and not of the decomposition of albuminous compounds'. 



Table 158. Vertical distribution of hydrogen sulphide 

 and of sulphates at Station 3 {1955) 



