lot) 
THE VOYAGE OF H.M.S. CHALLENGER. 
In the accompanying diagram the values of the alkalinity, x, arc laid down as 
' 9 issue; the ordinate, y, of the thick curve gives the number of cases per hundred 
. hich the alkalinity of a “ surface ” water, in the sense of Table IV., has the value 
expressed by the abscissa; the ordinates of the thin curve do the same in reference to 
the bottom waters. We sec from the curves that 
1 . The alkalinity ranges substantially from .r = 0’140 to ,'e = 0 , 1G4, 
2 . From 0T40 to 0*148 the surface waters, while from O' 1 48 to 0*160 the bottom 
waters, are decidedly in the majority. 
3. The most probable, ?.e., the most frequently occurring value of the alkalinity is 
For the. surface-waters, about 0'14G=t0'002. 
For the bottom-waters, about 0'152±0'003. 
Assuming the surplus alkalinity in the bottom waters to be owing to additional lime, 
w. have f< >r such extra lime, per 55'43 gnus, of chlorine, or per 100 grms. of total salts, 
(i'Cim 7 .') • of i Hi'. Tin- difference brought out by the discussion of our 
< b-t ■■nil i 1 1 tioi, I i Hu' (page 37) a bd ween waters from greater depths 
i if ■ !: and v.at<-n from h than 1 0 1 fathoms, was 0*0132 per 1 00 of chlorine. 
•ntly0'0070 per 100 il alt . Theagrecment is very satisfactory, though 
it# degree of closeness must be deemed accidental. 
• • ■ n 1 at i «.f tie alkalinity, the bromine, and the supple- 
b ■ f • ' r 1 ■ ii"'.'. a bl< to corn ed the average composition 
e d e'd from tie- 77 anal;. . <• tabulated on pages 23 to 25. 
