i:u 



PS veil E. 



[January — February' 1SS4. 



periuientirig with it in iSSi. It is a better in- 

 secticide and cheaper in its crude form than 

 when pure, but is more injurious to plants in 

 that form. It has been applied to grape vines 

 bv pouring a kilogram of it in a trench froin 

 15 to 20 cm. deep near the stock of the vine, 

 and then filling the trench with earth. 



Dr. T: Taylor said that he had recom- 

 mended the use of naphthalin for killing 

 phylloxera about ten years ago. and promised 

 to read a paper on the subject at the next 

 meeting of the society. He had not placed 

 the substance in the ground. 



Dr. W . S. Barnard said that naphthalin 

 might prove valuable as an insecticide, if 

 made cheap enough and so applied as not 

 to injure the plants. He had devised a 

 method and apparatus by which those insect- 

 icides which are dangerous to plants, such 

 as kerosene, cyanide of potassium [KCN], 

 and bisulphide of carbon [CS^], might be 

 used so as to be safe for the plants and de- 

 structive to insects in the ground. These 

 substances have usually been applied on the 

 surface of the ground or buried shallowly. 

 either among the roots or above them, but 

 when brought in contact with the roots, in 

 strength, they kill them. When applied in 

 volatile form they are not so injurious. 

 Naphthalin and kerosene especially should 

 be placed deep below the roots. The appar- 

 atus, which Dr. Barnard names a '-netlier- 

 insertor." consists of a tube which is made 

 to fit closely around a central solid shaft 

 somewhat longer than the tube and pointed 

 at its lower end. The tube may have cm 

 internal diameter of 15 nin). and the shall 

 a diameter of u mm. The upper end of the 

 tube expands like a bowl. The upper por- 

 tion of the shaft is weighted with a heavy 

 ball so disposed that the shaft can be grasped 

 above the ball. By withdrawing this shaft 

 partially from the tube and then returning 

 it with force, as the lower end of the tube 

 rests on the ground, both tube and shaft can 

 be driven into the ground to an\' required 

 deptti. The sliat'l is then wliolh withdrawn 



and the insecticide poured into the tube, by 

 \vhich means it is placed beneath the roots 

 witliout coming in contact with them. The 

 tube is then withdrawn, and the hole made 

 bv it filled with earth. The insecticide, being 

 volatile, rises through the ground and be- 

 comes diffused. With this method of appli- 

 cation kerosene is probably superior to naph- 

 thalin. 



28 Dec. 1883 —Dr. T : Taylor read a pa- 

 per "On naphthaline [sic], itseflectson seeds, 

 plants, insects and other animals," describing 

 the results of experiments made by him in 

 1872 and since. He found that its vapor pro- 

 duced asphyxia in various degrees in different 

 animals. Winged /'/^i'//o.vc;-« i>iti/oliae viere 

 killed almost instantly. Aphides succumbed 

 readily when confined with the vapor. Co- 

 leoptera resisted its effects several days. 

 Imagos of Dorypliora decemlitteata died in 

 ten days, but recovered if sooner brought 

 into fresh air. Females of Calliphora r>omi- 

 torid aborted their eggs and then recovered. 

 Flies, bees and wasps were anaesthetized, 

 but recovered if soon brought into fresh air. 

 Ants and termites were killed by the vapor, 

 or were driven away if free to depart. Crick- 

 ets, roaches, locusts and other insects were 

 driven away. Rats and mice were driven 

 . away, and frogs were i-endered torpid. Earth 

 worms were driven out of the ground and 

 killed by placing naphthalin in the bottom 

 of a flower-pot where the worms occurred. 

 Insects infesting seeds were killed by enclos- 

 ing the seeds in jars with naphthalin. Seeds 

 enclosed with naphthalin for two years after- 

 wards germinated, though the odor of the 

 naphthalin was as strong at the end of that 

 time as at the beginning. Three tender 

 plants were kept in an atmosphere of naph- 

 tlialin vapor for thirty-six hours causing a 

 single leaf on two plants to wilt, and not 

 affecting the third plant. One hour was 

 sufiicient to kill the insects on the plants. 

 Naphthalin acts more powcrfulh" when moist- 

 ened. 



