CONTENTS. 9 



Department Bulletin No. 798. — A Survey of the Fertilizer Industry. P£ge. 



Introduction 1 



Materials used in mixed fertilizers 2 



Sulphuric acid and acid phosphate 4 



Sources of nitrogenous materials. 7 



Potash-bearing materials 12 



Production of mixed fertilizers 13 



Stocks .--.-■-: : ; ]<> 



Imports and ey ports of fertilizer ingredients of importance in foreign trade . . 18 



Publications of Department pertaining to fertilizers 26 



Department Bulletin No. 799. — A Study op the Rots of Western White 

 Pine. 



Losses due to fungi 1 



Local pathology of western white pine 2 



Field studies of the rots in western white pine 4 



Relation between rot and ^'B.rious factors 6 



Age 6 



Size 8 



Infection age 11 



Injuries 13 



Sporophores 15 



Discussion of results 19 



^lethods of control 22 



Summary 23 



Department Bulletin No. 800. — The Whorled Milkweed (Asdepias 

 galioides) as a Poisonous Plant. 



Part I. — Introduction 1 



Historical summary and review of literature 1 



Description of A sclepias galioides 5 



Distribution and habits of the plant 6 



Part II. — Experimental work 8 



Horse experiments 13 



Cattle experiments 15 



Sheep experiments 17 



Chemical examination 20 



Part III. — General discussion and conclusions 25 



Symptoms 25 



Autopsv findings • 28 



Pathology 28 



Toxic and lethal doses 31 



Susceptibility of different animals 33 



Delay in develoi^ment of symptoms 33 



Effect of repeated doses 34 



Seasonal variations in toxicity 36 



Relative toxicity of leaves and stems 36 



Local variations in toxicity 37 



Remedies ■ 37 



Eradication of the Avhorled milkweed 38 



Prevention by care of stock. .- 39 



Summary 39 



Literature cited 40 



Publications of Department relating to plant poisoning of live stock 40 



