toxic to other micro-organism. Penicittium glaucum, Bacillus subtilis 

 and Proteus vulgaris flourished when sown upon it even in concen- 

 trated solutions. 



Similar experiments attended by similar results were made with 

 oranges and lemons affected by Penicillium italicum and P. olivaceum. 



Laurel Leaves as an Insecticide. The Gardeners, Chronicle, 

 No. 3618, p. 382. London, April 30, 1910. 



Pot-plants have been freed of aphis by placing the plant in a 

 box with crushed laurel leaves, when, after 10 minutes, the aphides 

 appear to be all dead. The insecticidal action of the laurel leaves 

 is due to the fact that they contain a glucoside which, when the 

 leaf is injured, is acted on by a ferment contained in the leaf, and, 

 decomposing, gives off the excessively poisonous gas, hydrocyanic 

 acid. If the laurel leaves are placed in a basin and a drop or 

 two of chloroform added the gas is liberated more quickly and the 

 insects sucumb to it sooner. This treatment is handy when an 

 occasional pot requires insecticidal treatment. 



J. AUGUSTUS VOELCKER. Potato-spraying Experiments 1909. 



Journal of the R. Agric. Soc. of England, Vol. 70, 1909, 

 pp. 362-388. 



At the Woburn Experimental Station of the R. Agric. Soc. of 

 England potatoes were grown in 1909. 



The " sets " were planted in May, 12 tons per acre (30 146 kgs. 

 per hectare) of farmyard manure having been previously applied. 



At the close of June, no " potato disease " had as yet shown 

 itself; upon a portion of the field some experiments with different 

 kinds of " spraying mixtures " were carried out. 



The applications consisted of: 



1) the ordinary Bordeaux mixture (sulphate of copper and 

 lime) ; 



2) Woburn " Paste " introduced by Mr. Pickering, of the 

 Woburn Experimental Fruit Farm ; 



3) Strawsonite. 



On the unsprayed portion a plot was left as it was, and on a 

 second portion, when disease began to appear at the end of July 

 the " tops " of the potatoes were cut off altogether. 



Disease was very prevalent throughout the crop and the results 

 of the applications were remarkable. See table: 



26 



