726 PHILOSOPHICAL TRANSACTIONS. [aNNO ld72. 



Cape Cette, is by a cut of 800 fathoms, joined with the deep lake of 

 Thau, which cut is almost finished. And when altogether perfected, it will 

 prove a considerable harbour and place of safety for those that navigate in this 

 part of the Mediterranean, called the Gulf of Lyons. 



But the main advantages aimed at by this communication of the two seas are 

 three : first, that by this means Languedoc will be enabled to vend their com- 

 modities of oils, wines, grain, wool, in which that large province abounds. 

 Secondly, that whereas hitherto they have been obliged to carry all the mer- 

 chandises of the Levant, with great charge and danger, all along the coast of 

 Spain round about, through the Straits of Gibraltar; the same may henceforth 

 be brought to Bourdeaux, and other ports of France lying on the ocean, by a 

 much shorter, surer, and even, as it is thought, a cheaper way. Thirdly, that 

 henceforth a man may travel round about France by water, save four days jour- 

 ney by land. For by taking boat at Guyse on the river of Oyse, lately made 

 navigable above Fere, one may descend to its mouth, where it enters into the 

 Seine; and then, passing St. Germain, St. Denis, Paris, Corbeil, Melun, go 

 up as far as Montreau, and there take the river Yonne, and go as far as Aux- 

 erre, where you quit the river and go by land to Chalons, seated on the Soane; 

 descending thence to Lyons, and so falling down to Tarascon ; and having left 

 the Rhone, take the Robine of Aigues-mortes, which is an ancient channel 

 communicating from that river with the lakes of Languedoc ; and so afterwards 

 go up through the channels of Narbonne, Carcassone, and Castlenaudary to 

 Tolouse ; thence pass on the Garonne to Bourdeaux, and there embark, and 

 coast it about that part of France which lies on the ocean, and so re-enter the 

 Seine, and see Roan and the other towns lying on that river, until you come 

 again to the mouth of the Oyse, whence you first parted. 



Some Animadversions on the Theory of Light of Mr. Isaac Newton^ 

 Prof, of Mathematics in the University of Cambridge, printed in 

 No. 80. In a Letter of April 9, 16*72, N.S. from Ignatius Gas- 

 ton Pardies* p. Prof of Mathematics in the Parisian College of 

 Clermont. Translated from the Latin. N° 84, p. 4087. 

 I have read Mr. Newton's very ingenious hypothesis of light and colours. 



* Ignatius Gaston Pardies, a French Jesuit, and professor of mathematics in the Parisian college 

 of Clermont, was born in l636. He entered the Jesuits order at l6, and after some time he devoted 

 himself entirely to mathematics and natural philosophy. In this latter branch he followed the opi- 

 nions of Descartes, though he feebly affected the contrary. He died at Paris in 1^73, aged only 37, 

 of a contagious disorder caught at the Bicetre, where he officiated as a preacher and confessor. He 



