1872.] 



THE AMERICAN BEE JOURNAL. 



17 



ners and old ones uninformed and unwilling to 

 be informed. 



The wise man delights nature's ways to explore, 

 The fool is satisfied, because he knows no more, 



Men who want to succeed in bee keeping at 

 the present day, must avail themselves of the 

 opportunities which our bee journals, bee books 

 and well informed bee men give to the public, 

 to e lucate themselves in this science of manage- 

 ment and cull ure, then and not until then can 

 they expect success. 



Old Grandfather. 



Marine, Madison County, Ills., 'May 20, 1872. 



[Translated for the American Bee Journal.] 



Honey dew on the leaves of a Linden. 



On the 21st of July, 1S69, at Liebfrauenberg, 

 France, the leaves of a linden were covered on 

 their upper surface with a viscous and very 

 sugared matter. The tree had contracted the 

 honey dew disease ; a kind of manna frequently 

 observed not only on lindens, but' also on many 

 other trees. I have seen it on a plum tree, and 

 what is more rare in France, on an oak tree. 



On the morning of the 22d, the honey dew 

 was so abundant, as to fall in large drops on the 

 ground. It was a rain of manna. At 8 o'clock 

 in the afternoon, the dew dropped no more from 

 those leaves exposed to the sun. It was so thick 

 that one could touch it without soiling his fin- 

 gers. It formed a kind of transparent and flexi- 

 ble varnish. As soon as the leaves were in the 

 shade, the dew returned to the liquid state At 

 9 in the evening of July 23d, the leaves on the 

 extremity of the branches, were carefully washed 

 and sponged to remove all sugared matter. 

 At six in the morning of the 24th, the leaves 

 that had been washed the evening before, 

 seemed to be free from dew ; yet with a magni- 

 fying glass one could perceive some glittering 

 points formed of very little drops. At seven in 

 the evening, the leaves were in the same state. 

 The day had been warm, the thermometer indi- 

 cating 29° (83° Fahrenheit). On the 25th, 

 many drops of honey were spread over the 

 leaves, but none upon the main nerves of the 

 leaves. At three in the afternoon, the ther- 

 mometer indicated 30°. 



In the night of the 26th, the leaves were 

 washed by a heavy rain. It was impossible 

 to watch the progress of secretion on the leaves. 

 A swarm of bees settled on the tiee. On the 

 28th, in the morning, the leaves were covered 

 with spots of dew, that had appeared during 

 the night. On the 29th, the dew increased. On 

 some leaves it occupied one-third of the surface. 

 At 2 P. M., the thermometer indicated 29'. On 

 the 30th, the dew was very abundant. This 

 linden remained covered with it until the begin- 

 ning of September, when it was stopped by long 

 and persistent rains. 



On the 22d of July and the first of August, 

 the dew was gathered by washing the leaves. 

 The product treated by the sub-acetate of lead 

 to eliminate the albumen, the mucilage, &c, 



&c, gave a syrup in which some sugared crysr 

 tals were found. 



This honey dew was found to contain sugar 

 similar to that of sugarcane. After some yeast 

 was added, the sugar disappeared completely, 

 yet in the fermented liquor some dextrine was 

 found. 



The analysis of the substance gave : 



Gathered July 22d, August 1st. 



Cane sugar . . 48.86. . . . 55.44. 



Fruit sugar . . 28.59. . . . 24.75. 



Dextrine . . . 22.55. . . . 19.81. 



100. 



100. 



The reader will notice, that the proportions 

 of the ingredients were not the same in the 

 honey dews gathered at different times. Doubt- 

 less nobody could expect to find exactly the 

 same proportions at different times. What is 

 most remarkable, is the striking analogy of the 

 proportions of the ingredients of the honey dew 

 of the linden and those of the manna of Mount 

 Sinai, which is composed as follows : 



Cane sugar . . . 55. 



Fruit sugar . . . 25. 



Dextrine .... 20. 



100. 

 By comparing the dew spread on the sickly 

 leaves of linden with the sugar contained in 

 healthy leaves we find : 



Cane sugar. Fruit sugar. Dextrine. 

 In one square m«ter 



of healthy \eav> s 3 gr. 57..., gr. 86. 



In dew gathered on 



meter of sickly 



leaves 13.92 7. 20 5 62. 



Difference 



.18. :;j. 



6. 37. 



5. 62. 



The honey dew exuded by the sick leaves of 

 linden is therefore considerable, and further- 

 more, dextrine, which is found in those leaves, 

 does not exist in a healthy leaf. 



From the measures taken upon a tree of the 

 same age and size, it results that the leaves 

 could cover a surface of 120 square meters. On 

 the 22d of July, the tree was supporting 2 and 

 3 kilogrammes of dew (4 to 6 lbs A 



In the normal condition of vegetation, the 

 sugar elaborated by the leaves under the influence 

 of light and warmth, penetrates into the organ- 

 ism of the plant with the descending sap. In 

 the abnormal state which determines the forma- 

 tion of the dew, the sugar matter is accumu- 

 lated on the upper surface of the leaves, either 

 because it is produced in larger quantities, or 

 because the motion of the sap is interrupted by 

 the viscosity resulting from the appearance of 

 dextrine. 



The honey dew cannot be caused by the meteor- 

 ological influences of warm summers. It is true 

 that this linden secreted dew during a period of 

 drouth in a hot summer, but it should be re- 

 membered that only one tree was attacked by this 

 disease, and that only a few rods further, there 

 were some lindens quite healthy. ■> 



Some authors pretend that plant lice after 

 having sucked the dew from the parenchyme of 

 the leaves, spread it afterwards, scarcely modi- 



