SEA-FISHERIES LABORATORY. 261 



had floated to the top and contained a good many bubbles of 

 gas. The contents were well stirred up and a sample taken 

 for titration ; the result was 8-5 c.c. A Sorensen determination 

 gave a match at 9-1 Borate and 0-9 c.c. HC1, equivalent to 



p„,io- 8 - 9 . 



The next titration made in this experiment was carried 

 out at 11.30 a.m. on February 16th. There had been a little 

 bright sunlight on the afternoon of February 15th, and a 

 dullish morning on the 16th. The titration gave 11-1 c.c. The 

 Sorensen determination gave an alkalinity exceeding the full 

 strength of the Borate solution, that is to say above P H ,10 " 91 . 



This shows that in an interval of three days in February, 

 the small quantity of seaweed used in the experiment had been 

 able to increase the alkalinity of two litres of sea- water almost 

 to the maximum point. 



The bottle containing the sea-water and green seaweed 

 was taken over to Liverpool and exposed on the roof of the 

 Bio-chemical Laboratory. The weather was fairly bright, and 

 the bottle was exposed to diffuse light during the day, but was 

 not in any direct sunlight. Analysed on February 17th, that 

 is, four days from the commencement of the experiment, it 

 gave an alkalinity corresponding to 124 c.c. per 100 c.c. of 

 centi-normal acid. A titration against methyl-orange for 

 total alkali gave 24-0 c.c. of centi-normal acid. 



Here again the full point of alkalinity is reached at almost 

 exactly one half of the total alkali available. 



The quantity of seaweed in the water was separated and 

 analysed. Dried from adherent moisture and weighed in the 

 moist condition, it amounted to 3-05 grams. After drying 

 at 105°C, this yielded 0-568 gram of dried matter. 

 Incinerated this left 0-180 gram of ash, or about 30 per cent, 

 of the dried weight. The ash contained Na, Mg, Fe, CI, and 

 S0 4 , and P 2 5 . There was a considerable amount of iron in 

 the ash. 



