EASY EXPERIMENTS WITH WATER POLLUTION

Growing yeast cells in warm water. . .softening water with polyphosphates. . .investigating the biodegradability of a soap and a detergent. . . . Such activities can be pointless or meaningful de. pending on the context in which they are undertaken; fortunately Sootin orders them logically and integrates them with pages of basic information on the pollution problems and treatment methods under investigation. In chapters on sedimentation, filtration, chlorination, biodegradability, toxic metals, etc., Sootin implicitly guards against slipshod conclusions (a common pitfall in books of this sort) by considering pros and cons of different approaches, emphasizing the large number of samples legally required in ongoing tests, and pointing out just what information a certain measurement does not give you. Miles ahead of Simon's Science Projects in Pollution (KR 1972) and a valuable aid for junior high school lab study.