INTRODUCTION 



637 Dairy. 



639 Fisheries. 



66 Chemical Technology. 



66 1 Chemicals. 



662 Pyrotechnics. 



663 Beverages. 



664 Foods. 



665 Oils, etc. 



666 Ceramics. 



667 Dyeing. 



668 Miscellaneous. 



669 Metallurgy 



6699 Assaying. 



30 



