I 



be used, "because of danger of escape of metallic compounds 

 into the soil. 7/ith clean tinned surfaces, there is 

 no difficulty in making the soldered joints without 

 flux using wire-solder and the gas-blowpipe. A soldering- 

 iron is much more difficult to handle and less satis- 

 factory. The sealing-wax should be of the best qualit.. . 

 The red variety, as furnished by Dennison and on sale 

 at all stationery stores, was found quite satisfactory. 

 It should be melted gently in a dish and must not be 

 burnt or overheated prior to application. 



Seals made in the manner described have been 

 applied to nearly one hundred plant individuals of 

 eight species with only one case of injury, this case 

 being due, probably, to an undetected injury with the 

 gas-blowpipe during sealing. Seals have lasted as long 

 as 4 months without leakage, but in some cases cracking 

 and leakage will occur in 4 to 6 weeks, especially if the 

 enlargement of the stem is rapid. This cracking may be 

 repaired by cautious softening of the grafting-wax with 

 a stream cf hot air or with a very small flame of the 

 gas-blowpipe; or, more safely, by pouring new grafting- 

 wax (melted as before) into the cracks and building it 

 up (when semi-solid) further about tjie stem. In cases 

 of extremely rapid growth the stem may enlarge so much 

 as to reach and press upon the inner surface of the 

 sealing-wax collar. In this case the old collar must 



be cracked away and a new and larger one built up and filled 



