757 



4- Oil Fumes. Korff^ used lead oxid as an addition to boiling linseed 

 oil in order to test experimentally the influence of oil fumes. He was led 

 to make these experiments by the injuries which had occurred near a 

 linseed oil and varnish factory. Just as in the decomposition of fats by 

 alkali, a mixture of fatty acid alkahes, soap, is produced, a mixture of cor- 

 responding lead salts, lead plaster, is formed similarly by the decomposing 

 of fat with lead oxid. In both cases glycerine occurs as a by-product. 

 When the glycerine, or fat, is heated to a high temperature fumes of akrolein 

 are formed which smell like scorched fat and quickly pass over, through 

 oxidation, into an akroyl acid which is recognized by its suffocating odor. 

 Yellow red to brown spots are produced in the intercostal fields, or along 

 the edges of the leaves according to the nature of the plant. These increase 

 in size with longer action, spread and actually unite. Most of the cells of 

 the leaf mesophyll, especially of the spongy parenchyma, collapse because 

 of the loss of turgidity. The cell contents contract from the walls and 

 the chloroplasts. form greenish yellow to brown masses. Finally the struc- 

 tureless cell contents and walls become brown. The elimination of tannin 

 is especially noticeable in the epidermal cells, the contents of which take on 

 a bluish black color with ferric chlorid. The flesh of apples and pears 

 which have been exposed for 4 hours to the oil fumes has an oily rancid 

 taste. 



Since akrolein, obtained by boiling glycerin, produced the same phe- 

 nomena the injuries from oil fumes may in all essentials be ascribed to this 

 substance. 



5. Turpentine Fumes. Molz- made experiments on the effect of 

 turpentine fumes, because a case was brought him for observation in which 

 the leaves of grapevines were said to have been injured by the fresh coating 

 of oil in the grape house. The action of turpentine fumes on the grape 

 leaves became noticeable after a half hour in the slight discoloration of the 

 edges and the increased curling; after an hour, apple leaves showed a 

 weakly reddish browning; after three hours, an intense dark red brown 

 discoloration of the upper side. The grape leaves became an olive brown. 

 At times some green areas were found within the brown surface, so that 

 the leaves looked dappled. Rose leaves turned an olive brown ; pear leaves, 

 a shiny, blackish gray. Molz suspects the cause to be a process of oxy- 

 dation produced by "the existence of 'terpentinozone' and its action on the 

 'bradoxydable' substances of the cell." 



6. Carbolineum. Like tar, Carbolineum is used, on the one hand, as 

 a coating substance for the framework of greenhouses, hot beds, stakes, etc., 

 in order to increase the resistance of the wood to moisture; on the other 

 hand, as a remedy for injuries to trees and a means of destroying injurious 

 insects. The great difference in opinion as to its effectiveness is due in part 



1 Korff, G., ijber Einwirkung- von Oldiimpfen auf die Pflanzen. Pi^akt. Bl. f. 

 Pflanzenbau u. Pflanzenschutz 1906, Part 6. 



2 Bericht der Kg-1. Lehranstalt fur Wein- Obst- und Gartenbau zu Geisenheim 

 a. Rh. 1905. 



