REPORT OF THE CHEMIST. 193 



publication. The volatile oil distilled from the flowers has proven 

 attractive to the boll weevil. 



The results of the study of cyanogenesis in the common grass, 

 Tridens flavus, showing that during maceration cyanogen may dis- 

 appear, have been published. This observation signifies that many 

 of the physiological studies upon cyanogenesis need revision. 



The study upon boron absorption by plants discussed in the report 

 for the year 1915 has been published. 



A phytochemical laboratory has been established. It will under- 

 take chemical investigations of the proximate principles of those 

 plants which are of especial importance in connection with the en- 

 forcement of the foods and drugs act. 



Carbohydrates. — A new sugar, the only heptose hitherto discov- 

 ered in nature, d-manno-ketoheptose, has been separated from the 

 avocado. The data are ready for publication. A large number of 

 investigations upon the preparation, the mutarotation, and the ro- 

 tatory power of sugars and sugar derivatives have been completed 

 and prepared for publication. Some of the results were published 

 during the year in the following papers : " The Acetyl Derivatives 

 of the Sugars"; "The Isomeric Pentacetates of Glucosamine and 

 Chondrosamine" ; " The Isomeric Tetracetates of Xylose and Ob- 

 servations Eegarding the Acetates of Melibiose, Trehalose, and 

 Sucrose " ; "A Fourth Crystalline Pentacetate of Xylose and Some 

 Related Compounds"; "A Second Crystalline ^-Fructose Pentace- 

 tate " ; " Crystalline (i-Methyl Fructoside and Its Tetracetates " ; 

 " The Preparation of Melibiose " ; " Bromoacetyl Xylose and $- 

 Triacetyl-methyl-xyloside." 



Papers have been published upon the occurrence of sucrose in 

 relatively large amounts in a new seedling grape and upon the occur- 

 rence of sucrose in grapes of American origin. Bulletin No. 335, 

 entitled "Development of Sugar and Acid in Grapes During Ripen- 

 ing," has been issued. 



Flora of foodstuffs. — An investigation of the range of conditions 

 under which organisms of the Bacillus botulinus group may cause 

 sickness or death in human beings and in domestic animals has been 

 started. It was found that a strain of this organism obtained from 

 a food poisoning case produced a very powerful poison. In coopera- 

 tion with the Bureau of Animal Industry this poison was shown to 

 affect rabbits, donkeys, and horses very quickly, cats in some cases 

 and not in others, and not to affect fowls. 



Because the losses to individual packers of sardines from swelled 

 cans may be as high as 30 per cent of the yearly pack, this form of 

 spoilage has been studied in the hope that means for preventing 

 this waste may be found. The organism causing spoilage very 

 rapidly forms spores which are killed only at high temperatures. 

 Therefore, aside from ordinary cleanliness, careful processing at 

 high temperatures is necessary to prevent the subsequent swelling of 

 cans. In the " red feed " within the stomachs of " belly-blown " 

 sardines a gas-producing bacterium, pathogenic to guinea pigs, has 

 been found. A spore-bearing, gas-producing anaerobe identical with 

 that found in sardines was isolated from two different consignments 

 of spoiled sweetened condensed milk. B. mesentericus ruber was 

 found to be the cause of the rose-pink color of certain spoiled sweet- 

 ened condensed milks. 



