Longevity of Cut Flowers. 2.51 



lead nitrate. The reservoirs, which were the same size, provided 

 .an equal pressure on each stem, and should force an equal amount 

 of liquid through the stems into the graduated flasks. The stems 

 being of equal diameter, they should have approximately the same 

 xiumber of vessels, and unless blocking occurred in one and not in 

 the other, the same amount of water and lead nitrate should pass 

 tthrough ii^ the same time. 



Experiment 1. — Time, one hour. 



Stem A, water only, amount collected -5 ccs. 



Stem B, lead nitrate, amount collected 5 ccs. 



Experiment 2. — Time. 4.5 minutes. 



Stem A, water only, amount collected 5 ccs. 



Stem B, lead nitrate, amount collected 5 ccs. 



Experiment .3 (with same stem as Experiment 2). — Time, one 

 ihour 15 minutes. 



Stem. A, amount collected 7 ccs. 



Stem B. amount collected 7 ccs. 



"Experiment! 4. — Time, twn hours. 



Stem A, water only, amount collected 5 ccs. 



Stem B. lead nitrate, amount collected 3.5 ccs. 



"Experiment 5. — Time, three hours. 



Stem A. water only, amount collected :.. .5 ccs. 



Stem B. lead nitrate, amount collected 5 ccs. 



These experiments show that the vessels are more open to the 

 'passage of lead nitrate solution tliau water. The viscosity of the 

 lead nitrate solution is slightly greater than that of water, but its 

 density is greater, and the greater head balances the higher vis- 

 cosity largely. Neither facror Avould cause more tlian a 5 to 10% 

 difference in the rate of flow, whereas the differences observed 

 amount to 700 to 1000%. and this fact can only be explained by 

 presuming that some form of blocking of the vessels intervenes to 

 prevent the passage of water, but this is not developed when lead 

 ■nitrate is passed through instead of water. This is proved by 

 microscope examination of sections of the stems which have been 

 used in the experiments. Stem A showed extensive blocking, 

 whereas the vessels in Stem B were quite empty and with open 

 lumina. 



This method of preserving wattle blossom could be quite easily 

 carried out in the household. A few crystals of lead nitrate to a 

 quart of water should make a solution of a sufficient strength to 

 ■preserve the blooms without having any harmful effect. 



