486 
NOTE ON THE COMPOSITION OF 
Other samples were tested, as regards their phosphate 
contents, with the following results : — 
Per cent. 
Calcium phosphate 
1. Gitoi Cave, 18/8/18 .... 
2. Gitoi Cave, inside, 18/8/18 
8. Gitoi Cave, 18/8/18 .... 
4. Gitoi Rock, underneath cave . 
5. Gitoi Rock, above cave .... 
6. Gitoi (sample collected previous to Safari) 
7. Gitoi Cave, deposit selected by natives, 
3/8/18 
8. Gitoi, outside cave, 13/3/18 
9. Gitoi (sample in envelope) 
10. Bagau, upper bed in cave 
11. Bagau Cave, upper bed in cave, 12/3/18 
12. Bagau Cave, lower bed in cave, 12/3/18 
13. Kibroise Cave, lower bed below the ngenda 
rock, 13/3/18 
14. Kibroise Cave, ngenda rock, 15/3/18 
15. Kibroise Cave, upper rock, 15/3/18 
16. Kipchebos Cave, 14/3/18 
17. Kipchebos Cave, lower bed of rock, 14/3/18 
18. Kipchebos Cave, upper bed of rock, 14/3/18 
19. Kipchebos Cave, No. 2 (from envelope) . 
20. Chemosit Rock, at bridge, 16/3/18 . 
5-35 
0-56 
0*56 
0*42 
0-84 
0*7 
0-28 
0*24 
2-31 
0-3 
0*2 
0-39 
0-2 
0-49 
0-2 
0-59 
0-75 
0- 3 
1- 46 
0-6 
It will be observed that the phonolite above the worked 
deposit, and also the vesicular lava below, contain varying 
amounts of phosphoric acid, but not in an unusual amount. 
It is probable that the action of water, charged with carbonic- 
acid gas, has in times past infiltrated between the phonolite 
and the vesicular lava (which often appears as a rhyolite) 
and has effected a decomposition of the latter, and deposited 
a certain amount of phosphatic cement. The amount of 
this is very variable, and does not appear to have any economic 
value. 
Cattle and goats showed an unmistakable partiality for 
the crushed rock in spite of the uninteresting analysis, and 
