gyg ON DYEING REDS ON COTTON. 



could not undergo the numerous manipulations and repeated 

 dryings, either in the open air or by the heat of a stove, to 

 which the cotton is subjected, without being entirely disen- 

 gaged ? Were it to be urged, that the alkali is rendered 

 iixed by combining with the cotton ; I should require proof 

 of this, the contrary of which is shown by experiment. 

 Composition g u t the property thus ascribed to ammonia of rosing cot- 

 red. ton > tnat i s °f brightening the tint of madder red, and im- 

 parting to it warmth, lustre, and liveliness, is equally un- 

 founded; for these effects can be produced only by forming 

 with white marseilles soap and muriate of tin a metallic 

 soap, in which the oxide of tin is held in solution by soda. 



Sheep's dung Thus, since neither does ammonia possess the properties 



useful by its ., , ; - . . , , , 



albumen and ascribed to it, nor is it contained in sheep s dung, we must 



gelatine. i o0 k f or the cause of its effects in some other principle. Now 



this can be nothing but the albumino-gelatinous matter so 

 abundantly contained in sheep's dung : to convince ourselves 

 of which, we have only to attend to the manner, in which 

 it is used. 

 Mode of em- J n the first place the dung is macerated in a solution of 

 tloying it. soda ^ of t ^ e 8trengtn of about 4 » j- gp# gr< 1.027], for some 



time. The effect of this maceration is evidently the solution 

 of the albumen and gelatine by means of the alkali. A cer- 

 tain quantity of this solution, passed through a sieve and di- 

 luted with a solution of soda at 2° [sp. gr. 1*013], is mixed 

 with thick or mucilaginous olive 'oil; and thus a kind of 

 liquid animal soap is formed, with which the cotton is care- 

 fully impregnated. 

 This impreg- In this process the cotton, by combining with the albu- 



nates the cot- an( j g e i a tine, approximates to the nature of animal 



ton with oiut & rr . 



mal matter. substances ; which, as is well known, have a stronger at- 

 traction than vegetable substances for colouring matter. 

 The combination appears to be farther promoted by the oily 

 principle, that combines with the cotton at the same time. 



Intestinal fluid We now see why authors, who have written on India red, 



equally useful recommend the use not only of the dung, but also of the 



intestinal liquor of the sheep ; which it would be much more 



advantageous to employ, were it possible to procure it in 



sufficient quantity for the demand. 



* The 



