268 Dr. Beddoes's Observations on the Process for 
observations, must be in a great measure ascribed to the li- 
beral curiosity of William Reynolds, whose enterprising 
spirit and inventive genius have improved our machinery, en- 
larged our manufactures, and changed the face of a large dis- 
trict in his native county. 
I have the honour to be, &c. 
Shifnal, Shropshire, 
February 14th, 1792. 
THOMAS BEDDOES. 
P. S. The residuum of 486 grains of cast iron, the same as 
that used in experiment 1. weighed 487 grains, after being dis- 
solved in weak vitriolic acid, and heated to a dull red heat ; 
the same quantity of iron, after the experiment, afforded a re- 
siduum of 39 grains, and a little more ; in the residuum left 
by equal quantities of iron, before and after the experiment in 
the unglazed tube, there was a difference of five grains ; the 
solution of the iron that had been submitted to the experi- 
ment went on very slowly ; and would not have been effected 
by vitriolic acid in many months. In the latter case, I used 
some muriatic acid, which quickly dissolved it : in the former, 
weak aqua regia was used for the solution of a very small part 
of the whole lump. I suspected lead to have caused the slow- 
ness of the solution in the first case, but there can be no such 
suspicion in the second. The difference between these resi- 
duums tends to shew that plumbago was consumed by the* 
heat : but they do not shew the loss accurately ; for in the re- 
siduum of the iron that had been fused in the first experiment, 
there was a small quantity of vitriolated lead ; and in the other 
