362 J.D. Daua on the Consolidation of Coral Formation. 
X. The absence of carbonic acid from sea-waters is a point 
which Prof. Horsford endeavors to prove by reference to several 
analyses. But is it true that carbonic acid is evolved as he allows, 
from the decomposition of animal matter in the mud or sands, 
forming the bottom of coral-reef regions, and yet that none 
escapes, so as to be found in the waters of these regions? It is 
obviously impossible. 
any analyses have actually found the carbonic acid or car- 
bonate of lime. 'To meet the case fully, the analyses should be 
made of waters from reef regions, and not of those from the 
open sea. But Darondeau and Henry have found carbonic acid 
even in the air dissolved in various sea waters at different depths; 
and as their results are of some general interest, we cite the fol- 
lowing table from the Annales de Chemie et de Physique, \xix, 
103. The latitudes and longitudes are reckoned from Paris. 
Density | Sas i108 
3 Y parts of water, 100 parts of gas. - 
Time collected., Lat. Long. Depth. j,,, 2, , at 0°C., & 760|/——_—- i 
NORE On Meh Sees DE GMOS & 10°C. am, pressure. |Oxyg.|Nitrogen}Carb. acid 
Aug. 30, 736:119 8’ n. |108° 50’ w Surface | 102594 | ; 83:33 | 10°51 (?) 
vd ie = 0 fath.| 102702 2:23 10:09} 71:05 | 18:06 
Mar. 19, 37 11° 43’ nj 87° 18! £.) Surface | 1:02545 1-98 5°53} 80°50 | 13°97 
bs Fess 9 200 fath.| 102663 3 04 3:29] 38:56 | 58°15 
May 10, ’37 18° 0’ n.| 85° 32 z.) Surface | 1-02611 191 6°34} 80-34 | 13°32 
¥ ng r 02586 2°43 5-72| 64-15 | 30-13 
July 31, 37 24° 5's. | 5290’ w. | Surface | 1-02577 1:85 84] 77-70 | 12°46 
Pha {450 fath.| 1:02739| 2-7. 9-85| 53-23 { 31-92 
| Aug. 24, °37 30° 40's! 119 47’ x. 00 fath.| 102708 2:04 4:17! 67-01 | 2882 _ 
which admit of ready reduction to extreme fineness.” In men- 
tioning my objection to this view, he says :—“ It is unfortunate 
that we find the author (Prof. Dana) elsewhere remarking: ‘The 
Nullipores, properly calcareous vegetation, (stone plants, ) flourish 
best along the line of breakers and form thick accumulations 
3 
and they arise from successive growths over one another of these 
incrusting stone-plants, 
Prof. Agassiz found in the West Indies, large accumulations of 
fragments of tender calcareous Alge; and these Prof. Horslo 
evidently had in mind: but a calcareous mud is almost as uy 
_— by the moving waters out of the fragments of coral as of 
