PREFACE. IN looking back over the past ten or twelve years, it is difficult to realize the rapid advance made in combating the insects and fungi which attack our cultivated plants. It is not going too far to say that the discoveries made within this period have worked almost a revolution in certain lines of agriculture. So phenomenal has been the progress in this direction that we are sometimes led to think that we have gone forward too fast, for in our intense desire to make the work thoroughly practical we have in many cases merely skimmed the surface, overlooking some of the most important fundamental questions involved. However this may be, the fact remains that America to-day stands well to the front in the discovery and application of practical methods of dealing with the numerous insect and fungous enemies of cultivated plants. The advance in this department has been so rapid that it has hardly been possible for investigators to keep track of all that has been written on the subject, nor has it, under the circumstances, been an easy matter to pause and consider what is to be the final outcome of work of this kind. This seems to be a fitting time, therefore, to take a broad survey of the subject in order that we may see where we stand. Mr. Lodeman has done this in the present volume, in which is given a clear, concise statement of the existing condition of our knowledge on the spraying of plants and the fundamental principles underlying this operation. As to the future, it can only be said that the prospect for broadening the work so well begun is exceedingly promising. As yet it cannot be stated that we have a well-defined science of plant pathology, but gradually the investigations and thought in this direction are being crystallized. It is now realized that to truly understand and appreciate pathological phenomena we must be familiar with physiology, the normal life processes of plants. After all, the highest aim of the investigator in this field of research is not to deal only with effects as he finds them, but to study causes, as it is only by this means that the true nature of many of the phenomena involved can be obtained. Following this line, we shall in the future look for a science capable of elucidating the problems which form the very basis of agricultural and horticultural pursuits. B. T. GALLOWAY. WASHINGTON, D.C. CONTENTS. First Applications to Plants - Present Distribution of Insect and - phur - Paints - Washes - Forsyth's Composition Ashes- Sand Plaster - Burnt Bones - Decoction of Walnut Leaves shells Sea-sand- Mortar Rubbish - Clay - Tanner's Bark - Leather Scraps Salt Corrosive Sublimate Alcohol. Scotch Snuff Cayenne Pepper - Aconite Pigeon Dung- Formulas containing these Ingredients — Applications recom- pillars - Bed-bugs - Brown Turtle Insect - White Scaly Coc- - - Sulphur - Downy Mildew of the Grape in France - Powdery Materials, and Stocks - Phenic Acid Emulsion. Origin of the Bordeaux Mixture (page 24). - An Accidental Dis- covery Early Experiments in its Use - Downy Mildew first systematically treated with Bordeaux Mixture - Other Mate- rials tested--First Published Formula for the Bordeaux Mix- ture Tomatoes sprayed with Bordeaux Mixture for Rot- Recommendations for Treating Potatoes - Treatment of Beaune - Treatment of Millardet - Spraying with Simple Solution of - - - Origin of the Ammoniated Copper Fungicides and Various Com- binations (page 30). The Use of Eau Céleste A Dilute Bordeaux Mixture - Bouillies Bourguignonnes. Powders (page 32). — Podechard's — David's — Sulphosteatite — Perfection of Fungicides (page 34). Stock Solutions for the deaux Mixture Céleste-Bordeaux Mixture and Molasses- Tests of Fungicides - and Combinations - Treatments for Pear Diseases. Insecticides (page 50). — Soap — Alcohol — Aloes — Oxalic Acid — - Fichet's Insecticide- Petroleum Kerosene Emulsion - Sul- phide of Potassium - Benzine - Glue - Salicylic Acid - Red IN OTHER CONTINENTAL EUROPEAN COUNTRIES (page 53). Treatments for Oidium Tuckeri — Introduction of the Grape Downy - - Slow Adoption of the French Methods. - Potassium Sulphide - Experiments with Fungicides - Introduction of French and Ameri- Spraying for Leaf-eating Insects and the Codlin-moth (page 59). - Appearance of the Potato Bug- First use of Paris Green First use of Paris Green for the Canker-worm - First use of Spraying for the Curculio (page 68) The Arsenites and the - |