Correspondence ivilh M. Van Mons. C7 



He proposes that charts should be varnished, but did not state 

 tlie kind of varnish that would bear rolling- and unrolling re- 

 peatedly. 



Signor Zamboni j^resented to the Society an instrument of his 

 own construction, being an atteni})t to cxbibit a perpetual mo- 

 tion. The principle on which it acts has been known in this 

 country several years. It merely consists of two of De Luc's 

 electrical cokiums or galvanic piles, placed perpendicularly at 

 the distance of about six inches, and each glass tube is sur- 

 mounted with a brass ball ; between these pillars a steel needle is 

 jjlaced to move on an axis; the longer arm of this needle touches 

 the U])pcr end or ball of each pile, and receives from it a suffi- 

 cient repellent force to drive it to the adjacent ball, and vice 

 versa : in this manner the n^otion is continued. No ap])aratus 

 to measure time has yet been connected with this simple mo- 

 tion,' which is protected from the atmospiiere by a glass frame. 



XVI. Intelligence and Miscellaneous Articles, 



EXTRACT OF A LETTER FROM M. VAN MONS TO MR. TILLOCH*. 



Sir, — " x ou are probably acquainted with the new discove- 

 ries made at Milan, by Messrs. Moscati and Maury, relative to 

 the sun, its diurnal or rotatory motion, its volcanos, &c. I 

 send you a translation of the report pul)li3hed on this head ; I 

 also send you a note to what I have said on the metallo-fluores, 

 and another on mv new theory, which is that of caloric consi- 

 dered as a constituent part of all bodies containing oxygen, dis- 

 placed in the combinations and displacing itself in the decombi- 

 nations. Afterwards I admit hydrogen reduced into its gas into 

 all the combustible bodies, and into the metals, and sub-satu- 

 rated in all bodies which can, in their quality of bases, contract 

 eomlnnations. Hydrogen gas is a simple body ; oxygen gas is 

 composed of equal parts of oxygen and of caloric : the primi- 

 tive material of the globe, and without doubt the substance of 

 the other planets, also consists of equal parts of oxygen and hy- 

 ♦Irogen, without the least quantity of caloric, which would break 

 this relation : water is oxygen gas displaced in the ratio of ~ 

 from its caloric by two of hydrogen, and there result in this 

 way 15 parts of oxygen, 13 of calorie, and 2 of hydrogen. The 



* M'.jcli valuahlfi scientific infontiation from various parts of Europe 

 will t)f fo.unci ill tiiis coiniiiuiiicatio;i ; and we are liappy to he able to t.tate, 

 tliat yi. Van ^ilons hiis promised to continue his correspondence. The 

 further mntcriith alluded to in the present Icttci- have not yet come to hand. 



EniT. 

 E 2 metals 



