374 MISCELLANEOUS PRODUCTS USED IN AGRICULTURE. XVI. 



CflH 4 (OCH 8 )OH, arid creosol, C 8 H 8 (CH 8 )(OCH 8 ).OH. Wood 

 creasote is very poisonous both to animals and plants. 



" Little's soluble phenyle" is said to be obtained from wood 

 creasote." 



Many other antiseptic and disinfectant substances have been 

 obtained from coal tar. For an account of these substances a 

 treatise on organic chemistry should be consulted. 



"Formalin," the commercial name for a solution of form- 

 aldehyde, H a CO, in water. The nominal strength is 40% of 

 formaldehyde and a trace of formic acid is also present. The 

 liquid is stable in closed vessels, but loses the gas on free 

 exposure to air. 



Formaldehyde is one of the most powerful antiseptics and 

 disinfectants. Solutions of 1 in 10,000 or 20,000 will prevent 

 the growth of many micro-organisms and 1 % solutions produce 

 absolute sterility. 



Formaldehyde is an admirable fungicide and in sufficient 

 quantities acts as a powerful plant poison. 



In 1897 Windischf investigated the effect of various 

 strengths of formaldehyde solutions upon the germination of 

 cereals. In each case 200 seeds were allowed to germinate 

 between thick filter paper moistened with water and with 0'02, 

 0-04, 0-08, 0-12, 0-20, and 0-40% formaldehyde solutions. 



Wheat was almost wholly destroyed by the 0'12% solution, 

 whilst oats were only delayed in their germination by this 

 solution; with 0'20% solutions, barley, wheat and rye were 

 destroyed, and with 0'40% solutions, oats also succumbed. In 

 1901 he:[ extended the experiments to other seeds; the 0-2% 

 solution killed flax and rape and greatly injured lupins, peas, 

 and clover, retarded the germination of horse-beans, but did 

 not injure maize. Even a 0'4% solution, which killed all 

 other seeds, did not destroy maize. 



By shorter treatment of seeds with formaldehyde, it has 

 been attempted to destroy the smut spores in grain without 

 injuring the seed. Kinzel found that a 0*1% solution of 

 formaldehyde applied for one hour to rye, wheat, oats, barley, 



Rideal, p. 176. t Landw. Versuchs.-Stat. 1897, 223; J.C.S. 1898, abst, ii. 40. 



t Landw. Versuchs.-Stat. 1901, 241 ; J.C.S. 1901, abst. ii. 46<>. 

 Landw. Versuchs.-Stat. 1898, 461; J.C.S. 1898, abst. ii. 302. 



