CONTENTS. 



xvii 



V. An Enquiry concerning the Chemical Properties that have been attributed 

 to Light. By Benjamin Count of Rumfor^, F.R.S. M.R.I.A. p. 400 



Doubt whether light operates chemically in any other way than by generating heat. Experiments 

 on the vitrification of oxyde of gold by the heat of a candle ; and by folar light. Effeft of dilution 

 in rendering the particles more minute and fufceptible of elevated temperature. Curious inflance 

 of gold reduced by charcoal in the humid way with folar light — and without. 



VI. Experiments and Obfervations on the Nature of Sugar, and of Vegetable 

 Mucilage. By Mr. William Cruickfkank, Chemift to the Ordnance, &c. 



p. 406 



Chemical examination of fugar, honey, fugar of milk, gum arable, and gum tragacanth. Refults : 

 That fugar is compofed of carbon, hydrogen, and oxygen ; — fugar of milk contains more oxygen 

 and much lefs carbon ; — gum contains lime and azote as well as the principles of fugar ; — vege- 

 table farina cannot become fugar without water and oxygen ; — that neither fugar, if deprived of 

 oxygen, or combined with other matters, nor pure vegetable nor animal mucilage, is capable of 

 fermentation. 



VII. On the Art of covering Wire Cloth with a tranfparent Varnifli, as a Sub- 

 flitute for Horn ; and on other Objefts of Public Utility. By Alexis Rochon, 

 of the National Inftitute of France, &c. — — p. 412 



Chinefe manufadhire of horn. Wire cloth prepared for lanthorns with glue ; and with mica. 

 New covering for houfes. Medical bougies. 



VIII. On the Produftion of Nitric Acid by the Contaftof Oxygen very much 

 heated and the Air of the Atmofphere — — P- 4^3 



New phenomenon of nitric acid from manganefe. Conjedlures refpefting it. 



IX. Analyfis of the Chryfolite of the Jewellers, proving it to be Phofphate 

 of Lime. By Citizen Vauquelin — — — P* 4^4 



The chryfolite, being pulverifed and treated with fulphuric acid, afforded fulphate of lime, and the 

 phofphoric acid was difengaged. In another experiment the lime was taken up by muriatic 

 acid, and precipitated by the oxalic. From both experiments the flone was found to contain 

 54 parts lime, and 46 phofphoric acid, 



X. Account of a fingular Inftance of Atmofpherical Refraflion. In a Letter 

 from William Latham, Efq. F.R.S. and A.S. to the Rev. H. Whitfield, 

 D.D. F.R.S. and A.S, — — — — p. 417 



Uncommon view of the coaft of France from Great Britain at the diftance of forty or fifty miles. 

 Remarks and references to fimilar fa£ls. 



XI. An Account of EIe£trical Machines of confiderable Power, in which 

 Silk is ufed inftead of Glafs. (W. N.) — — p. 420 



Various non-<onduftors ufed for the excitation of eleftricity. Enumeration. Defcription of the 

 machines of Ingenhoufz, Walckiers, and Rouland, which operate by the friftion of filk. Their 

 power of excitation. 



Vol. II.— March 1799. ^ ^^^' ^^' 



