xi^ CONTENTS. 



Hiftorical h&s and obfervations, which prove the rapid growth and advantages to be derived from 

 the broad-leaved American black birch, the Athenian poplar, and the iron, wainfcot, or Turkey 

 oak. 



II. Abftradl of a Memoir of M. Prouft, on the Tanning Principle. By Citi- 

 zen Defcotils — — — — — P- 537 



The folution of muriate of tin precipitates the tanning principle from a decoftion of nut-galls, and 

 leaves the acid of galls in folution. Methods of obtaining the gallic acid and the tanning principle 

 feparate from each other. Precipitate of glue with tanning. The green fulphate of iron is not pre- 

 cipitated by either of the principles of galls. Difference of the precipitates of the red fulphate by 

 thofe principles. Application of the fafts to the procefs of dyeing black. 



HI. Notice of a Memoir of Citizen Guy ton, upon the Tables of the Compofi- 

 tion of Salts, and the Means of verifying the Proportions indicated by thofe 

 Tables — — — — p. 340 



When two falts, differing in their acids and their bafes, are of fuch a nature as to change their prin- 

 ciples by double eleftive attraction, as for example, the fulphate of potafh and nitrate of lime, it is 

 known that two new falts are formed ; namely, In the prefent inltance, nitrate of potafh and ful- 

 phate of lime : but the quantities of each bafe, fufficient to produce neutral falts in the firli: combi- 

 nations, are not the fame as will faturate the acids in the new compounds. If, therefore, the quan- 

 tity of one fait be fuch as to afford enough of its bafe to faturate the acid of the other, the bafe of 

 this lafi will be either more or lefs than is fufficient to faturate the acid of the firit-mentioned lalt. 

 In this cafe, it may be inferred, that one of the new compounds will be neutral, and the other not 

 fo. But the fafts refute this conclufion ; for the mixture fliews no redundance of either principle. 

 Why this happens is a new and interefting chemical theorem. 



IV. On Pafigraphy ; or, the Art of Writing which fhall be intelligible to all 

 Nations — — — — — p. 342 



The univerfal writing is not the means of rendering all languages intelligible to all nations ; in its own 

 nature it fuppofes the exiflence of one common language propofed to all nations for their acceptance 

 and ufe. Hiftory of the attempts and obfervations of various eminent men ; Lord Bacon, Des 



•Caftes, Becher, Dalgani, Frifichius, Kircher, Befnier, Wilkins, Leibnitz, Dc I'Epfee, and Condillac. 



KJeneral remarks. 



Y, Obfervatioiis on the Natural Hiftory of Guiana. In a Letter from William 

 Lochead, Efq. F.R.S. Edin. to the Rev. Dr. Walker, F.R.S, Edin. Regius 

 Profeffor of Natural Hiftory in the Univerfity of Edinburgh — p. 347 



•Obfervations on the rivers, and their agency in forming the foil, of Guiana ; their creeks, floods, 

 tides, &c. 



VI. On the fiippofed Revival of Infcdts after long Immerfion in Wine or other 

 intoxicating Liquor. By Mr. John Gough — — p. 353 



Sfetperiments on various infers, which prove that the popular notion of their revival many months 

 after their immerfion in fermented liquors is ill founded. 



VII. Various Notices rcfpefting the Arts in Turkey. — Jeweller's Foil. — Glue, or' 

 Maftic for S:ones and Metals. — Calling of Malleable Iron. — Filtration by 

 Afccnt. — Butter prefer ved without Sale. — Extemporaneous Yeaft p«355 



VIII. Ob- 



