328 
Hints for the Formation of 
A singular Ignition and Oxydation of Iron 
Dr. Juch gives the following singular notice 
“ I had,” says he, “ a small leather flask filled with 
iron filings, which I frequently used with my electropho- 
rus both charged and uncharged. I had occasion one 
day for a quantity of pure iron, and having no other at 
hand, had recourse to the filings in the flask, which I 
knew were pure. I emptied it on a piece of paper. I 
laid the paper on my hand in order to convey it to the 
place of its destination ; but I had scarcely held it a few 
seconds when I perceived a strong heat, which increased 
so much that I could no longer hold the paper. Some 
minutes after, the paper became brown, and at length 
took fire. It did not, however, flame. The iron filings 
were in a state of ignition ; and when the heat had de- 
creased, I found the iron converted into a highly friable 
oxyd.” 
No. 43. 
Agenda ; or a Collection of Observations and Researches 
the Results of which may serve as a Foundation for a 
Theory of the Earth . By M. Be Saussure. 
(Continued from page 267.) 
CHAP. XVIII. 
A. Observations to be made on Volcanoes at the Time of 
an Eruption. 
1 . The form, dimensions, and elevation of the crater. 
2. The colour, elevation, and other sensible qualities 
of the flames and the smoke. 
3. Phenomena which preceded the eruption, subterra- 
nean noise, earthquakes, extraordinary movements of the 
sea. 
4. Phenomena which accompany the eruption: as 
* Tilloch, vol. 5 . p. 208. 
