«j Objects of the Art cfDftngy Gfr. 35 j 



If we allow of the authenticity of the above 

 fadls, they will certainly account, in a f^if- 

 faftory manner, for the different effefts produced^ 

 by the fame tinging materials, on fubjedls comV 

 pofed of wool, to thofe produced on filk, cotton 

 or linen. If they be all porous, and the dim^n- 

 fions of the pores of each be different, the fub- 

 flance, which has the largcfl pores, will be capa- 

 ble of receiving a much greater portion of tinging 

 matter, than that which has the fmalleft. It 

 may feem fome confirmation of this theorv that 

 cloths, woven in various modes, are faid to 

 receive colour, more or lefs freely, according to 

 their texture. But perhaps the various fhades^ 

 obfervable in thefe cafes, may proceed from fome 

 circumftances, in the refledlion and tranfmiffion 

 of the rays of light, arifing from the alteration 

 in the pofition of the refledting and tranfmitting 

 bodies. 



To this theory it has been objefted, and with 

 much appearance ofreafon,* that the colouring 

 matter is not merely infinuated into the pores of 

 the fubftance to be dyed, but becomes firmly 

 attached to it; and, that the more numerous 

 and large the pores are, the more of the colour- 

 ing matter fhould be abforbed, and, as it were 

 hidden, within them ; whereas wool, which is 

 fuppofed to contain pores, more numerous and 



Macquer DifKonaire de Chymir, Edit. 2. Vol. IV, 



A a large 



