290 



Mistaken opi- 

 nion of it. 



Sheep's dung 

 distilUd. 



Results. 



Residuum, 



Oils. 

 Phlegm. 



ON DYEING REDS ON COTTON. 



solid notions of the mode of action and influence of the 

 sheep's dung bath, the first applied to the cotton. 



"Various opinions have been broached on this subject; but 

 the experiment, of which I am about to give an account, 

 will at least dissipate every idea of its containing a large 

 quantity of volatile alkali, to which La Pileur d'Apligny 

 ascribes its property of rosing reds. 



In May 1806 I distilled 61-19 gr. [945 grs] of fresh sheep's 

 dung in a coated glass retort, to which I fitted a receiver 

 furnished with a tube of safety, and a tube for collecting the 

 gaseous products. The retort was placed in a reverbera- 

 tory furnace, and gradually heated till the bottom was red. 

 On receiving the first impression of the fire, a very clear 

 liquid passed over. On raising the heat, white vapours 

 were evolved, oily, not very copious ; and soon succeeded 

 by drops of a very fluid oii, the colour of which was a very 

 fine orange yellow. To this oil succeeded a second, thick, 

 almost concrete, of a blackish brown, and smelling strongly 

 empyreumatic. During the distillation about 50 cubic 

 inches of elastic fluids passed over, which were found to be 

 a mixture of carburetted hidrogen and carbonic acid. 



Having broken the retort, I observed, that it was lined 

 interiorly with a slight coating of coal, exhibiting the metal- 

 lic lustre, and assuming on exposure to the air, though only 

 in some places, the blue colour of prussiate of iron. At the 

 bottom I foynd a dull black coal, tolerably dense, retaining 

 the sha^fe'of the matter subjected to analysis, without any 

 sensible taste, and exhaling a smell precisely like that of 

 tobacco smoke. » 



This coal weighed 7*8 gram. Heated in a porcelain cru- 

 cible it readily took fire, and before the vessel was redhot. 

 £ observed, that it emitted oily and empyreumatic vapours, 

 owing no doubt to a small quantity of oil, with which it was 

 still impregnated ; and that it burned with a small white 

 flame. After burning six hours with a fire well kept up, it 

 left 3'68 gr. of a gray substance, which was found to be 

 phosphate of lime. 



Of the two oils mentioned above I collected 3*91 gr. 

 The coloured liquor in the receiver, contaminated with a 



few 



