NATURAL HISTORY. 23 



we have all the ' Tinctures ' [of the Pharmacopoeia]. This is so remark- 

 able that I think it might also detennine the fact of itself. I find it 

 almost impossible to keep the spirit clear [in anatomical preparations] 

 even after a dozen shiftings ; and this much more so in some [prepara- 

 tions] than in others. 



Certain animal substances retain their native colours in spirit the 

 same after death as before; as, e.g., the shining colour of many fishes 1 , 

 the shining surface in the bottom of a cat's eye (tapetum) 2 . A carti- 

 lage, tendon, &c, are as bright in spirit as when alive ; the two last are 

 not so transparent, from the coagulation that takes place. 



The native colours of vegetables do not keep in any liquor after they 

 are dead ; they all approach to the white or yellow : but this effect 

 will take place sooner or later according as they die fast or slow. If 

 they are made to die fast, they will retain their colour longer ; if slow, 

 they will lose it in the action of death*. 



Minerals and animals give the shine to colours much more than ve- 

 getables. Polished metals are the best instances of this. Silk, some 

 chrysalises, and beetles [have shining colours]. Vegetables give fine 

 colours, but never polished or shining 3. 



The more imperfect animals are, the more they approach towards a 

 vegetable in many circumstances, if not all. The casting of hair is 

 similar to the casting of leaves : much more so is the moulting of fowls, 

 and their debility and withered combs at the time. Vegetables may be 

 said to sleep all winter : and the winter sleeping of snakes is, as it were, 

 living in some measure in a state of non-existence. 



In their method of propagation they are similar. The egg of the 

 animal is like the seed of the plants ; and the eggs and their manner 

 of hatching in the more imperfect animals are very similar. 



Of the Dependence that Vegetables and Animals have on each other, 

 especially the last upon the first, both in breeding and future support. 



Many terrestrial animals, and probably most so those of the Insect 

 Tribe, depend very considerably on vegetables for their support. In 

 many of the Insects, both in their maggot and changing states, they 

 not only feed upon the vegetable, but oblige the vegetable to grow 



* Cooks and picklers are very sensible of this. 



1 [Hunterian Preparations, No. 1884.] 



2 [lb. Nos. 1732, 1733. See also the red pigment in parts of the skin of the Turkey, 

 Preps. Nos. 1880, 1881.] 



3 [Mr. Cliffc has added the following Note : — " They are never so hard as those 

 shining parts of minerals and animals. Some seeds are as brilliant and shining as 

 many metals."] 



