Dear Editor, According to The New York Times' April 22 article on the drought in Texas, Gov. Rick Perry was prompted to urge prayers for rain over the weekend. If the governor had studied his American history as well as his Bible, he would know that rain is caused not by prayer but by human sacrifice. The Mayans and Aztecs would do up some 20,000 in a weekend when the droughts got really going. Prayers? That's not realistic. Or practical. Or effective. Simply doesn't work. But when the blood flows the rain falls.