52 FIRST ANNUAL KEPORT OF THE STATE ENTOMOLOGIST. 



the treed black with the deposited soot, and efFectually prevented the 

 attack of the curculio. 



Coal-tar, known also as gas-tar, is one of the residual products of 

 gas manufacture. As the result of scientific investigations, these resid- 

 uals, which were formerly of no value whatever but were simply a 

 waste material, to be disposed of at no inconsiderable cost, have, of late 

 years, become valuable articles of commerce, as they now form the basis 

 of manufactures of great importance. Thus, the corporation of 

 Bradford, England, has lately been offered $50,000 per annum for the 

 ammonia and tar liquids, which eight years previously had been dis- 

 jiosed of at a yearly expense of about S4,000 — the former being now 

 almost the only source of ammonia, which has become so popular as an 

 agricultural fertilizer, and from the latter is obtained asphaltum, car- 

 bolic acid, cresylic acid, naphtha, the various and beautiful aniline 

 dyes, anthracine, and other valuable products. In this country ammo- 

 niacal liquid is seldom utilized. In the vicinity of New York it is 

 employed to a limited extent for fertilizing purposes. Coal-tar is pur- 

 chasable at a very low price — at the Albany gas-works at S2.50 per 

 barrel. In the Western States, during the large demand for it in the 

 destruction of locusts, its prices ranged from from $3 to $8 per barrel. 



11- Gas-Lime as an Insecticide^ 



The value of this material for checking and for averting insect dep- 

 redations is recognized among the agriculturists of England, where it 

 appears to be growing in popular favor, as may be seen from the fre- 

 quent references to it in Miss Ormerod's Manual of Injurious Insects 

 and her later Annual Reports. It has been extensively experimented 

 with, and, for the most part, with quite satisfactory results. For ex- 

 ample, it was found, when sprinkled among onions, to check an at- 

 tack of the onion-fly ; it was successfully used against the cabbage- 

 worm [Pieris rapes) by distributing it over the plants, probably both 

 killing the larvre present and preventing egg-deposit (Manual, p. 37) ; 

 and applied when fresh to the ground in the autumn as a dressing, and 

 "pointedin" with a few inches of the surface soil, it killed tliepupgeof the 

 celery-leaf miner [Tephritis onoponUnis) lying an inch or two beneath 

 the surface (lb., p. GO.)* 



A refuse material in gas manufacture. — Gas-lime is a refuse 

 material produced in the manufacture of illuminating gas. The com- 

 mon slacked lime, slightly dampened, is spread in numerous shelves 

 of perforated iron in a cast-iron chamber, and as the gas distilled from 



*It would doubtless be of equal value, when used in the same manner, against other 

 pupre lying near the surface, as those of the onion-fly, cabbage-fly, turnip-fly, etc. 



