Zapotitlan, Saturday Aug 25. Started away about 7 A.M. for San Juan Ryan in rains. Arrived there about 9.30 and then on horse back for three miles further. Here we collected some fairs from the Trujillo beds, and later about one mile further away to the south in the Alancania beds. Had a turbulent lunch with plenty of sun. The horse back riding is not my job and for me to own gain the saddle. Returned to Zapotitlan at 6.30. Return exceeding tired. The distance between Tehuacan and Zapo- titlan is 26 1/2 Kilometers. From the latter place to San Juan Ryan is probably 8-10 kilometers further. San Antonio is the place where much salt is made. Some ozone is here but it is not pure enough. Aguilar thinks that ozone deposits go with brine springs in arid countries. He is now working on the problem. One of the Cutacans deposits is a salt bearing lagoon and it is for this place that the spring waters is charged with salt. This brine water is carried on