158 t Memoirs of Erasmus Darwin, M.D. 



but little surprise. Any one, he said, might draw their fin- 

 ger through melted lead, if they did it somewhat quickly; 

 and having in his hand a ladle full of melted solder, he in- 

 stantly passed his finger through it. He said he had often 

 passed a red-hot piece of iron over his tongue, -and seen 

 others do it without injury, in the first experiment, he said, 

 it was necessary that the finger should be perfectly- dry — if 

 otherwise, the person might get what he called a thimble, i. e. 

 some of the metal would stick to the finger and give a severe 

 burn. In the experiment of passing a red-hot iron over the 

 tongue, the iron, he said, should be very red- — if only of a 

 black heat, nearly but not red-hot, it was sure to burn the 

 tongue most severely. — The latter circumstance gives much 

 countenance to the solution of the phaenomenon offered by 

 W. S. It seems somewhat analogous to what takes place 

 with a drop of water let fall on a plate of red-hot iron, which 

 takes a much longer time to evaporate than a similar drop 

 let fall on hot iron which would hardly shine in the dark. 



I shall here state another fact, which may, perhaps, but 

 not quite so satisfactorily, be explained on similar principles. 

 A gentleman informs me that he has seen an iron founder 

 skim melted iron with his hand. The founder stated that he 

 could only do it when the iron was boiling hot : — if of a 

 lower heat, it would burn him. — A. T. 



XXVIII. Memoirs of the late Erasmus Darwin, M.D. 



[Continued from p. 39.] 

 DARWINIANA. 

 X1.YDROCEPHA.LUS interims, or dropsy of the ventricles of 

 the brain, is fatal to many children, and some adults. When 

 this disease is less in quantity, it probably produces a fever^ 

 termed a nervous fever, and which is sometimes called a 

 worm fever, according to the opinion of Dr. Gilchrist, in 

 the Scots Medical Essays. This fever is attended with great 

 inirritability, as appears from the dilated pupils of the eyes, 

 in which it corresponds with the dropsy of the brain. And 

 the latter disease has its paroxysms of quick pulse, and in 



that 



