1. 1 What is Selectivity? purpose, and crop protective agent for the A biologically-active substance is said to be second, but there is no fundamental difference selective if it strongly affects certain cells with- of principle in their mode of action. out causing any change in others, even when the Drug therapy has two, fundamentally two kinds of cells are close neighbours. In living opposed divisions. The first of these strives to organisms, there are many substances, often improve the action of one of the cell's natural quite small molecules, which have been chosen agents by modifying the...

This book is about selectively toxic agents. That is to say, it is about those substances that affect certain cells without harming others, even when they are close neighbours. Toxicity need not be fatal. It can be made easily reversible, as is the case with general anaesthetics. Selective toxicity covers an immense field: most of the drugs used for treating illness in man and his economic animals, as well as all of the fungicides, insecticides, and weed killers that are used in agriculture. Essentially, this book is a discussion of the physical and chemical means which contribute to...

This practical manual is devised for organic chemists and biochemists who, in the course of their researches and without previous experience, need to determine an ionization constant. We are gratified that earlier editions were much used for this purpose and that they also proved adequate for the in- service training of technicians and technical officers to provide a Department with a pK service. The features of previous editions that gave this wide appeal have been retained, but the subject matter has been revised, extended, and brought up to date. We present two new chapters, one of which...