20 I N D E X. 



LaBucafaiiva [garden lettuce] yields good opium, Vol. IV. p. 391. See 



Opium . 

 Lake Erie. See ^r'le. 



Lakes, fubjeifl to tempefts, Vol. III. p. 63. 



Land, wlien and why colder or warmer than water, Vol. I. p. 274, 

 fpouis, account of two, Vol. II. p. 112 — of another formed firft oa 



the water, 115 — curious effefts of it, 116. 



air, experiments on. Vol. IV. p. 262, 266 — lefs pure than fea-air, 269. 



Landi (pocrj good effefts of caffia chamsechrifla thereon, Vol. III. p. 226. 

 Language (•writlen) an eflky on. Vol. III. p. 262. 



fa univerfaij proposed, Vol. IV. p. 167. 



Languages, two different ones ufed by the Natchez Indians, Vol. IV. p. 



193 — Dr. Collin's philological view of fome very ancient words in 



feveral. Vol. IV. p. 476 — mines of human antiquities, 478 — compa^ 



rative fpecimens of various languages, 485. 

 Lanius escuhitor, or great fhrike, fome account of, Vol. IV. p. 124. 

 Latitude of Norriton obfervatory. Vol. I< p. 22. 



of Philadelphia, 54. 



- of Lewes, 92. 



of Providence (N. E.) 103. 



of Newcaftle court-houfe, 93. 



of liohthoufe on Cape Henlopen, 93. 



of Cape Blaizc (W. Flor.) 253. 



of Mobile bay, ib. 



of Santa Rofa, ib. 



-- of town of Eric, Vol. IV. p. 231. 



— of the to^^^l of Natchez, Vol. IV. p. 449. 



La Plata, account of a huge fkeleton found there. Vol. IV. p. 259. 

 Latrobe ( B. Henry) his memoir on the fand-hills of Cape Henry (Vir.) Vol. 



IV. p. 439 — fupplement thereto, 444. 

 La'va erupted from mount Vefuvius, Vol. I. p. 28^, 2 85. 

 Laws and regulations of die Amer. Philof. Soc. Vol. I. p. v. — Vol, II. 



p. v. 

 Zfliu to encreafe the annual fubfcriptions and depofits of members of the 



A. P. S. Vol. II. F- xvii. 

 Lee-JIiore, a propofed contrivance to avoid it. Vol. II. p. 311. 

 Lenj'cs (two convex) invert objedls, and why, Vol. II. p. 37 — other curious 



appearances produced by them explained, 37 to 42. 

 Leprofy afligned as the caufe of the dark complexion cf Negroes, Vol. IV. 



■p. 289. 



various kinds de cribcJ, Vol. IV. p. 2S9. 



if Roy on the conftrudlion of hofpitals. Vol. III. p. 34S. 



Letters, new ones propofed. Vol. III. p. 277 — their affinities, 292. 



Lettuce [laiftuca fativa] yields good opium. See Opium. 



Lewes obfervatory, tranfit of Venus as obferved there in 1769, Vol. I. p. 



89 — couiies and diftances from it to tlie provincial weft line between 



Fenwick's 



