180 CORRESPONDENCE OF RAY. 



those who cultivate plants, and have the liberty and free- 

 dom to pluck up and observe their roots, have a great 

 advantage of those who see them only in one state, and 

 can take notice only of their superficial part, for that they 

 may, as Dioscorides advises, mark their several states of 

 first springing and growth, of consistency and declension, 

 and note their diflFerences, and so give us a perfect history 

 of their whole progress and several mutations. But I 

 should rather have been content with an imperfect and 

 defective history, so it had contained notes sufficient to 

 distinguish them from all others (because then I could 

 have inserted them in their proper places in the body of 

 the history), than to have waited for a more perfect and 

 accurate to be put as an appendix. 



I thank you for the account of the Hockesden earth, 

 and the rather because I was lately informed that it was 

 no natm'al bitumen mingled with it, but had its original 

 from the burning of a painting-shop standing over the 

 spot where the earth was digged up, and there was no 

 such earth round about, but just within that compass ; 

 so that, as the Corinthian brass was made by an acci- 

 dental mixture of metals melted down and running into 

 one mass at the deflagration of that city, so this bitumi- 

 nous earth became impregnated by a mixture of oils and 

 colours melted and mixed together, and soaking into the 

 ground at the burning of that shop. Whether there be 

 any truth in this you can best inform ; but I suppose 

 there is none, because you mention no such thing ; and 

 you have done very well thoroughly to examine the earth, 

 for that probably there may be good use made of it. 



I do herewithal send back yom- dried plants, and the 

 book wherein they were, with thanks for the use of them. 

 They have, I am sensible, received some prejudice which 

 could not be avoided. 

 Black Notley, Nov. 17, —85. 



