On the Precipitation of Calcium Carbonate. 23 



After 36 hours a dense cloud developed in the culture and strong nitrite reactions were 



given. 

 After 60 hours a dense cloud and scum developed in the culture and strong nitrite and 



faint ammonia reactions were given. 

 After 70 hours a dense cloud, scum, and bubbles developed in the culture and faint nitrite 



and faint ammonia reactions were given. 

 After 84 hours culture was less cloudy, with much scum, no nitrite or nitrate reaction, 



very faint ammonia. 

 Average temperature at which the culture was grown, 30° C. 



2. Sample collected from same spot under similar conditions, from a depth of 3 fathoms. 



1,000 c.c. Gran's medium was inoculated with 10 c.c. of sample. 

 After 20 hours a slight cloud developed in the culture and faint nitrite reaction was given. 

 After 27 hours a denser cloud developed in the culture and strong nitrite and faint 



ammonia reactions were given. 

 After 38 hours a dense cloud and scum developed in the culture and strong nitrite and 



faint ammonia reactions were given. 

 After 48 hours a dense cloud and scum developed in the culture and moderate nitrite 



and faint ammonia reactions were given. 

 After 63 hours a moderate cloud, thick scum, and bubbles developed in the culture and 



faint nitrite and faint ammonia reactions were given. 

 After 72 hours a slight cloud and thick scum, no nitrite or nitrate, and very faint 



ammonia reaction. 

 Average temperature at which the culture was grown, 29° C. 



3. Sample collected from a spot 6 miles south of Port Royal, wind ESE., force 4, high tide 



(slack). Taken from surface. 1,000 c.c. Gran's medium was inoculated with 



10 c.c. of the sample. 

 After 20 hours a slight cloud developed in the culture, no nitrite reaction was given. 

 After 2^ hours a slight cloud developed in the culture, faint nitrite reaction was given. 

 After 38 hours a dense cloud developed in the culture, strong nitrite and faint ammonia 



reactions were given. 

 After 48 hours a dense cloud and scum developed in the culture, strong nitrite and 



faint ammonia reactions were given. 

 After 63 hours a dense cloud and scum developed in the culture, moderate nitrite and 



faint ammonia reactions were given. 

 After 72 hours a moderate cloud, scum, and bubbles developed in the culture, very 



slight nitrite and faint ammonia reactions were given. 

 After 86 hours a moderate cloud and scum, no nitrite or nitrate and very faint ammonia 



reaction. 

 Average temperature at which the culture was grown, 29° C. 



4. Sample taken from surface water of the large mangrove swamp lying northwest of Port 



Henderson. 1,000 c.c. of Gran's medium inoculated with 10 c.c. of sample. 

 After 20 hours no cloud or nitrite reaction. 

 After 24 hours slight cloud and slight nitrite reaction. 



After 40 hours strong cloud and scum, strong nitrite and slight ammonia reaction. 

 After 75 hours cloud, scum, and bubbles, no nitrite or nitrate and slight ammonia 



reaction. 

 Average temperature at which the culture was kept, 30° C. 



5. Subculture from culture (i). 1,000 c.c. Gran's medium inoculated with 5 c.c. of culture 



(i), and kept at a temperature of 10° C. to 12° C. by means of ice. 

 After 100 hours the culture was quite clear and gave no nitrite reaction. It was then 



removed from the ice and kept at the room temperature, which averaged 30° C. 

 After 107 hours a dense cloud developed in the culture and strong nitrite and faint 



ammonia reactions were given. 

 After 120 hours a dense cloud, scum, and bubbles developed in the culture and moderate 



nitrite and faint ammonia reactions were given. 



