abstracts: phytochemistry 379 



Stirring the storage air has been found entirely to prevent the develop- 

 ment of scald. Thorough aeration during the first eight weeks of 

 storage was found more valuable than later ones. Apples packed in 

 boxes or ventilated barrels have scalded less than those in tight barrels, 

 especially when the storage room received an occasional ventilation. 

 Ordinary apple wrappers have had no effect on apple scald, and paraffin 

 wrappers but little, but wrappers soaked in various oils and fats have 

 entirely prevented the disease. Accumulations of carbon dioxide (i 

 to 6 per cent) have not favored the development of scald but tended to 

 prevent it. The experimental results indicate that apple scald is due 

 to volatile or gaseous substances other than carbon dioxide which are 

 produced by the apples themselves. They can be carried away by 

 air currents or taken up by various absorbents. C. B. 



PHYTOCHEMISTRY. — The distribution and characters of some of the 



odorous principles of plants.^ Frederick B. Power. Journ. Ind. 



Eng. Chem. 11: 344-352. April, 1919. 



In this paper, which does not permit of a comprehensive abstract, 



the author indicates the chemical characters of the great variety of 



compounds to which the odor of plants is due, the distribution of these 



compounds among the different plants, and the methods by which they 



are obtained. Among the cryptogamous or fiowerless plants, such as 



the algae, fungi, lichens, and ferns, there are very few which possess 



any marked or distinctive odor, whereas the phanerogamous or flowering 



plants contain such an exceedingly large number of odorous substances 



as to preclude a complete enumeration of them. These substances, 



many of which have been the subject of extended chemical study, are 



of such a diverse character as to include representatives of practically 



all the principal groups of organic compounds, comprising, for example, 



the hydrocarbons, alcohols, aldehydes, ketones, phenols and phenol 



ethers, acids, esters, and lactones. The odorous products of the plant 



are generally obtained by a process of steam distillation, and are then 



commonly known as essential oils or volatile oils, most of which are 



more or less complex mixtures, although frequently one constituent of 



them may largely predominate. Some of the essential oils are obtained 



by expression, such as those of the citrus fruits, notably the orange, 



lemon, and bergamot. In some cases the odorous principles of plants 



^ Abstract of an address of the retiring president of the Chemical Society of Wash- 

 ington. Delivered before a joint meeting of the Chemical Society and the Wash- 

 ington Academy of Sciences, January 9, 1919. 



