130 DONALD J. MATTHEWS. 
water was 0-044 mg. per litre ; this showed signs of an increase when the 
supply of land-water rose after rain. The figures are much lower than 
those found by Raben for the Baltic and North Sea. 
4. The amounts found by another method during the previous spring 
and summer are higher, but the figures cannot be considered quite 
trustworthy. 
Note.—Since the above was written, it has been found that boiling 
with potassium permanganate does not oxidise the whole of the phos- 
phorus with certainty. Duplicate analyses of a sample taken on Jan, 
17th, 1916, both gave 0:0190 mg. per litre. Two other portions were 
oxidised and found to contain 0:0449 mg. and 0:0569 mg. per litre. 
An attempt has also been made to determine whether any of the 
phosphoric acid is reduced to other forms in the short interval between 
the collection of the water and the beginning of the analysis. A sample 
of water was sterilised with toluol immediately after taking. A single 
determination showed 0:0350 mg. per litre in the original sample, and 
00375 mg. after oxidation. But the water for over a week had been 
extraordinarily clear and free from suspended matter, far more so than 
any of the samples given in the table, so that the experiment cannot be 
considered conclusive. 
BIBLIOGRAPHY. 
1. C. Scumipt.—Hydrologische Untersuchungen. Bull. Akad. Petersburg. 
Bd. 24, 1878. Quoted by Brandt. 
K. Branpt.—Ueber den Stoffwechsel 1m Meere. 2 Abhandlung. Wiss. 
Meeresuntersuch. Kiel, 1902. 
bo 
3. K. Branpr.—Untersuch. iiber den Gehalt des Meerwassers an spurenweise 
vertretenen Pflanzen-Nahrstoffen. Beteil. Deutschlands a.d. internat. 
Meeresforch. I, IT and III Jahresbericht. 
4. O. KrtmmMEt.—Ozeanographie I, p. 323. 
C1 
. Poueet, I., and CHoucnax, D.—Dosage colorimétrique de l’acide phos- 
phorique. Bull. Soc. Chim. France. 4 series, V, 1909, p. 104, and 
PX LOL ape G 29, 
