Transactions of the Prussian Gardening Society. 251 



The committee appointed to examine his theory are of opinion 

 that various causes may produce the cankei', but that the chief 

 are bruises, lopping off strong branches, or otherwise injuring 

 a tree at a season unfavourable to vegetation ; such as at the 

 end of a vv^et autumn, or during great drought or heat in 

 summer. Professor Link agrees with M. Wiederhold in 

 thinking that the soil is the principal cause of canker; and 

 this, we believe, is the general opinion in Britain. Wounding 

 trees, Professor Link acknowledges, may produce canker, 

 but only in a bad soil, and in consequence of a predisposing 

 tendency to that disease. 



5. Experiment on the Preparation and Application of a Liquid 

 Manure for Orange Trees. By M. Kleemann. 



Five bushels of rye were boiled in a copper till the grains 

 burst ; they were then taken out, the juice squeezed out of 

 them, the grains given to cattle, and the juice returned again 

 to the copper. Water, in which cow-dung had been steeped, 

 was added, so as to fill the copper ; and to this mixture was 

 thrown in about 3 lbs. of saltpetre. The whole being heated 

 and well stirred, was taken out, put into a larger vessel, and 

 diluted with rain water. A large orange-tree was watered 

 with it. " In a fortnight it began to push and blossom, it 

 became much greener, and, in six weeks' time, it became so 

 green, and grew so fast, that it might be considered one of the 

 finest of our trees. The young fruit, which were of a sickly 

 yellow, became green also, and grew to a good size. The 

 tree, during the whole summer, always dried sooner than the 

 others that were watered at the same time, and I was obliged 

 to give it a larger quantity of water. In the three following 

 years it produced very abundantly. I have taken 400 oranges 

 from it this year, and it promises an equally abundant harvest 

 for the year following. It has not been manured again with 

 this mixture, having been transplanted into a larger tub and 

 fresh soil, where it has nourishment enough without the aid of 

 liquid manure. I have since used the same composition every 

 April for such trees as were checked in their growth, and 

 uniformly found the same result, those trees always having the 

 darkest foliage and the largest fruit. I have also observed 

 that trees which had suffered much from the coccus (schild- 

 laus), mostly lost the insect in consequence of the application 

 of this mixture ; and I think it possible that they might be 

 kept entirely free from it, if they were watered with the liquid 

 for some years in succession. 



" I tried this liquid with pine-apples, and found that, by 

 applying it once, it had no effect at all in enlarging the fruit ; 



