<56 Caouickouc ilseoverei in North America. 



recent observations, he met with several advantages in tbiS 

 tedious process: namely, that of subjecting to a new ex- 

 amination the coefficients so well discu.^sed by M. Burg, 

 of extracting them directly from the observations, with the 

 changes which the mean arguments occasioned, of intro- 

 ducing the new equations which the observations required 

 clearly ; and yet not to lengthen the calculations, since, if 

 on one hand it increased the number of the equations, on 

 the other it simplified the formation of the arguments ; 

 which is an inestimable advantage, particularly for the cal- 

 culators of ephemerides. 



After having finished this work, M. Burckhardt sub- 

 jected his tables to a new proof, by comparing them with 

 all the passages of the moon by the meridian which could 

 be observed in the first ten months of 1811, either by him- 

 self at the Observatory of the Military School, or by M. 

 Bouvard, at the Imperial Observatory. 



We cannot say more at present on the subject of these 

 tables, for th-^y have been but a very short time in our 

 possession ; but every thing inclines us to think that they 

 will be at least as precise, and above all more convenient 

 even than those of M. Burg, and we trust that astronomers 

 will be gratified by their immediate publication. 



[To be continued.] 



XV. Intelligence and Miscellaneous Articles. 



CAOUTCHOUC DISCOVERED IN NORTH AMERICA. 



We are informed that Professor Barton has discovered 

 the substance called Caoutchouc, in considerable quantity, 

 in several vesretables growing abundantly in the vicinity of 

 Philadelphia," and in other parts of the United States. He 

 finds it in the berries of Smilax caduca, and other species 

 of this genus ; and has pursued the progressive modifica- 

 tions of this sin.rular substance from its first appearance in 

 the infant berry, — in which it occurs as a mere viscid 

 fluid, — to its complete formation in the adult fruit, in 

 which it shows itself in elastic plates, already formed. 



This, it is believed, is the first instance of the discovery 

 of Caoutchouc in a formed state in any vegetable : unless, 

 indeed, something of the kind docs take place in the Bi/po- 

 ch<Bri$ radicala. The Professor intends to pubHsh al 

 length, in the course of a few months, his experiments 

 and observations on the subject of this elastic matter, as 



the 



