26 N. H. AGR, EXPERIMENT STATION. [Bulletin 192 



leaf or fruit-eating insects, especially those feeding on leaves or fruit that are 

 soon to be used for human food: 



Dry Diluents. 



Effects of Dry Heat. 



Aqueous Extracts. 



Alcoholic and Ethereal Extracts. 



Repellent Properties. 



Poisonous Properties with Relation to Vertebrates. 



In carrying out the above inquiries much of the apparatus and methods 

 used in the study of pyrethrum will be available. We have very httle knowl- 

 edge concerning hellebore, although it has been used as an insecticide for many 

 years and is commonly recommended as a safe material to use on plants ready 

 to eat. Since we have no material that is knowTi to be effective and entirely 

 safe for use under such conditions, fm-ther information of an accurate nature 

 concerning hellebore would be of considerable value. 



REPORT OF THE DEPARTMENT OF 



FORESTRY. 



K. W. WOODWARD, 



The war deprived the head of the Department of his assistants, and during 

 this period he was the only man at the College engaged in forestry instruction 

 and experimental work. About 35 per cent of the time is devoted to instruc- 

 tion, 45 per cent to administration, 15 per cent to extension and 5 per cent to 

 experiment work. During the emergency the forester lectured on the use of 

 wood as a war-time industry, assisted the New Hampshire Fuel Administra- 

 tor and had charge of Map-Making in the Students' Army Training Corps 

 course. He co-operated with the College Extension Service and the New 

 Hampshire State Forester, and contributed one press bulletin and one exten- 

 sion bulletin in addition to contributions to the Journal of Forestry. 



Two projects constitute the main Station work of the Department: The 

 experiments in establishing artificial forests and the experiments in immature 

 white pine stands. 



EXPERIMENTS IN ESTABLISHING ARTIFICIAL FORESTS. 



These experiments were started in 1912, when six sample plots were estab- 

 lished to determine the conditions which are most favorable for the growth of 

 various. tree species. 



The growiih has been measured annualh', and the following results are now 

 apparent : 



Of the species planted, Scotch pine, European larch and Norway spruce are 

 growing thriftily. 



These plantations are now all at least five years old. The white ash planta- 

 tion died on account of excessive moisture. The average annual height 

 gro^\'th is as follows: 



