CONTENTS. 



Department Bulletin No. 226, — The Verbena Bud Moth: Page 



Introduction and history 1 



Name and synonymy 2 



Distribution 2 



Food plants •- . 2 



Description 3 



Habits and seasonal history 4 



Methods of control 6 



Department Bulletin No. 227. — The Toxicity of Fungi of Various Oils 

 and Salts, Particularly Those Used in Wood Preservation: 



Introduction 1 



Historical 2 



Tests conducted at the forest-products laboratory 14 



Toxicity of fungi of certain of the more important preservatives 31 



Summary 35 



Bibliography 37 



Department Bulletin No. 228. — Effect of Frequent Cutting on the 

 Water Requirement of Alfalfa and its Bearing on Pasturage: 



Introduction 1 



Method 1 



Results 2 



Bearing of results on the management of alfalfa lands 4 



Summer pasturage of alfalfa extensively practiced in Australia 5 



Department Bulletin No. 229. — The Naval Stores Industry: 



Need for improved methods: 1 



History of the industry in the United States 2 



Statistics of production 3 



Commercial utilization of products 8 



Formation and flow of resin in the living tree 10 



Principles underlying the distillation of crude gum 12 



Commercial methods of collecting crude gum 14 



Relative yields secured from cups and boxes 22 



Relative amounts of scrape formed by the box and cup systems 23 



Relative yields from different depths and heights of chipping 24 



Effect of turpentine operations on timber 25 



Quality of gum from boxed and cupped timber 27 



Commercial distillation of crude gum 27 



French methods of collecting gum 32 



French distillation methods 35 



Comparison between direct and steam heated stills 39 



The supply of longleaf pine for turpentine operations 40 



Possibilities of western pines as a source of naval stores 44 



Special problems investigated— Arizona and California western yellow pine. 47 



Suggestions for specifications 49 



Packing naval stores 50 



Cost estimates on a 20-crop turpentine operation 51 



Publications relating to the naval stores industry. 53 



Chronological list of United States patents relating to the naval stores 



industry 56 



Department Bulletin No. 230. — Oil-mixed Portland Cement Concrete: 



Introduction 1 



Oil -mixed concrete 2 



Appendix 16 



3 



