42 ANNUAL REPORT 
Vesuvius and at Bacoli, as well as at Montenuova. It is partly soluble in 
hydrochloric acid. The composition of two typical pozzuolanes is: 
| Per cents. 
| I* | [I** 
Silicacepe mea Va UU bes Sheu dviel we eon patch ae 47.85 | 73.00 
VAL unvian Aang visi, waka ce eect avai aera ada Sekine Meson mtlRoO 
Hlerric Oxide rr yes os eran tr vere other ee 9.75 | 1.55 
| VDoc tor ree ene reine nh rainy Ce lenin chang Oneliesi i od 10.00 | 0.65 
Ma ariesiar ei nestcrec tue ieuatcpeuc oyna dom epee ae aU eaeSb 
GossronMemitlone . aiieos meee ie orueeee: 6.10 | 4.30 
Tallies MeGe Uti tee aie whens area nes Foe eee 4.70 | 8.45 
Silica soluble in caustic potash ............. 15.70 | 12.40 
Silica soluble in sodium carbonate solution...| 2.30 2.00 
*Heichtinger, Chemische Technologie der Moertelmaterialien. 
**R, Feret, Tonindustrie Ztg. No. 15, Vol. 25. 
No. I is an Italian pozzuolane. No. II is found in Nebraska. 
Typical analyses of trass and santorin earth are as follows: 
Per cents. 
Trass. Seat 
SILICA oc: SSMS AN isal Saeed ay nel ne vee a gr acmeteat 59.75 | 65.55 
NITE Uae ie en UiSaie ter gare erteaasteneeec ..| 18.05 | 14.60 
Ferric Oxide NOE OS One COU AOE eee 3.70 4.10 
1 Distt pane N TARR une cen icamin yd salut 1.90 | 3.70 
Miaermes tare). Sai eenGaneun. a atetienava ark een ea 0.65 0.95 
TEGSS On TSMItIOIY Bessente es ceca ee eee ae 7.00 4.25 
Alkalies Jeb @isn) sce cnet cameo aets, yamine anew 8.85 6.50 
Silica soluble in caustic potash...... Jcoooscal L780 || 1A.C0 
Silica soluble in sodium carbonate solution...) 1.00 2.00 
*R. Feret, Ton. Ztg. No. 15, Vol. 25. 
