258 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



hydrochloric acid as estimated from a titration of its alkalinity. 

 A volume of 2,000 c.c. was measured off and to this a quantity 

 of green algal confervae found growing in a vessel in the 

 laboratory was added. The amount of moist algal matter 

 added was not estimated, but it certainly did not exceed half 

 a gramme. The algae were added at 12.15 p.m. on August 

 29th and the whole was placed in a wide-mouthed bottle, 

 which the mixture just rilled. The bottle was stoppered and 

 left in the open air exposed to daylight. A sample was taken 

 off and tested as to alkalinity on August 30th at 9.15 p.m. ; 

 the alkalinity had risen so that 3-8 c.c. of centi-normal acid 

 were required to neutralise 100 c.c. to phenol-phthalein. 

 Thus the alkalinity as a result of photo-synthesis in such a 

 restricted volume had already risen above anything naturally 

 found in sea-water. 



A second titration was carried out on September 1st at 

 10.20 p.m., that is about 82 hours from the commencement of 

 the experiment, when the alkalinity was found to have increased 

 enormously, 9-7 c.c. of N/100 acid being required to neutralise 

 100 c.c. of the solution to phenol-phthalein. A third titration 

 was made at 6 p.m. on September 2nd, the value of the 

 alkalinity to phenol-phthalein had now reached 11*1 c.c. A 

 fourth titration at 9-20 p.m. on September 3rd gave 11-7 c.c. ; 

 a fifth, on September 4th at 10.20 p.m. gave 12-3 c.c. ; a sixth, 

 on September 5th at 8.40 p.m. gave 12-2 c.c. ; and a seventh, 

 at 6 p.m. on September 6th gave 11 -4 c.c. 



A naked- eye examination during the experiment showed 

 that the algae remained green, and apparently the growth was 

 healthy until September 4th when the alkalinity had reached 

 its maximum. From this point onward the growth commenced 

 to turn brown and die, and on September 6th, when the alkalinity 

 had commenced to fall off again, the green organisms were 

 evidently dead. The drop in the figure was hence probably 

 due to bacterial decomposition. 



