Hard water (water containing dissolved calcium carbonate and/or sulfate is alkaline enough to use as a bluing agent by itself. New York City, Hot Springs Arkansas, and San Antonio Texas - in my personal experience - have tap water sufficiently alkaline that you can blue hematoxylin in it in a reasonable length of time.
The original Scott's solution was in fact devised as a substitute for alkaline tap water. Scott SG (Oxford). On successive double staining for histological purposes—preliminary note. Journal of Pathology and Bacteriology 1911-1912: 16,390-8. Scott notes that "As tap water varies in constitution from place to place, and even the alkaline tap water of Oxford from the oölite Cotswolds requires ten minutes with occasional changes for safe removal of acid, the artificial substitute mentioned above has been introduced." Robert Wyllie in 1970 told me that this bluing solution was widely used in Australia, apparently introduced by Oxonian histologists nostalgic for the tap water of their homeland. Wyllie was an Australian histochemist who worked in the pathology department at Johns Hopkins for a number of years. He greatly simplified Scott's original formula, and referred to this preparation as Scott's solution. Gary Gill popularized Scott's solution along with his well-known hematoxylins. Bob Wyllie (of blest memory) was an absolute genius in the histochemistry lab, but he was a very modest man. He published very little, and many of his ingenious techniques are totally lost (I have just a few of them). I spent a year as a research fellow in his laboratory in 1970. Bob Richmond Samurai Pathologist Knoxville TN _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet