CONTENTS. 



Department Bulletin No. 451. — The Chemical Composition of Lime- 

 sulphur Animal Dips : Page. 



Experimental materials and methods : 1 



Effect of storage 2 



Effect of lime added after dilution 3 



Effect of varying lime-sulphur ratio_ 4 



Effect of varying period of boiling 5 



Effect of varying concentration 6 



Occurrence and relations of calcium sulphite 7 



Ratio of polysulphid to thiosulphate 8 



Lower polysulphids ; effect of excess of lime 9 



Higher polysulphids; effect of oxidation 11 



. Conclusions 12 



Practical applications 15 



References to literature 16 



Department Bulletin No. 452. — The Chemical Composition of 

 American Grapes Grown in the Central and Eastern States : 



Introduction 1 



Extent of investigation 1 



Collection of samples 2 



Chemical composition of grapes examined 3 



Discussion of analytical results 15 



Summary of data on sugar and acid, for five years 16 



Department Bulletin No. 453— The Control of Damping-off of 



CONTFEEOUS SEEDLINGS : 



The disease , 1 



Economic importance of damping-off 1 



Relation between nursery methods and the control of damping-off 3 



Tests of soil disinfection for the control of damping-off 6 



Soil-disinfection tests summarized 14 



Cost of disinfectant treatments 19 



Secondary advantages from disinfectant treatments 21 



Conclusions as to soil disinfectants 24 



Soil treatments recommended 28 



Summary 31 



Department Bulletin No. 454. — The Effect of Cultural and Climatic 

 Conditions on the Yield of Peppermint Oil : 



Introduction 1 



Effect of soil and climate on the composition of peppermint oil 2 



Yield of oil from fresh and from dry plants at various stages of 



growth 3 



Physical and chemical properties of peppermint oil from fresh and 



from dry plants at various stages of growth 5 



Effect of light and shade 11 



Effect of frost action 12 



Conclusions 15 



Department Bulletin No. 455. — The Drying for Milling Purposes 

 of Damp and Garlicky Wheat : 



Introduction 1 



The drying of damp wheat 2 



The distribution of garlic 2 



The amount of moisture in garlic before and after drying 3 



The loss of moisture in garlic in warm and in hot wheat 4 



3 



