NOTES AND QUERIES. 27 1 



experience of the vigour of its growth, we have learned that 

 it ought to be planted " pure " ; but during the failure of seed 

 in recent successive seasons it sometimes became necessary 

 to " beat up " with the European variety, and in thinning and 

 pruning plantations the problem sometimes arises and will arise 

 more frequently as growth increases — If a choice has to be 

 made of either European or Japanese, which should be 

 sacrificed ? The European larch is subject to disease ; but 

 though the Japanese is (here, at any rate) free from disease, 

 its very extravagance of growth seems to foretell a too early 

 maturity for it to compete with its rival in height and diameter 

 and value as timber. Moreover, some of us, aware that the tree 

 was in its experimental stages, did not feel safe in trusting to 

 a '-pure" planting, and (wrongly, as we now know) planted 

 it " mixed." Thus the problem is becoming increasingly 

 imminent as regards individual young trees, whether or not to 

 destroy the adjacent Japanese larches, and so save the slower- 

 growing European. 



Can any reader supply details as to its native habit, so that 

 we may be guided more clearly ? 



Hugh Shaw-Stewart, 

 Ardgowan. 



Notes re Acetone. 



Acetone, so much used in the manufacture of smokeless 

 powder, can be obtained from different sources, but the main 

 supply comes from the dry distillation of acetate of lime, 

 and this in its turn comes from the dry distillation of wood. 



According to the kind of wood used and its dryness, the 

 amount necessary to produce a final quantity of i ton of acetone 

 varies between 34 and 70 tons. It is very difficult to get exact 

 figures as to the amount of acetone used in this country, as it 

 is sometimes imported as such both from the Continent and 

 from America, and is also manufactured in this country from 

 acetate of lime imported from the same sources. But as acetate 

 of lime is also used in large quantities for making other products 

 than acetone, its importation cannot be taken as a guide. I 

 understand, however, that the demand is under 5000 tons per 

 annum. This would entail a supply of wood of 170,000 to 

 350,000 tons of wood per annum. 



