f£ ANALYTICAL EXPERIMENTS AND 



fourth volume of the quarto feries of this Journal, as well as 

 from thofe of Profeffor Venturi, inferted in the fame work, I 

 learned how greatly the lateral reaction of the air, which is 

 put in motion by bodies paffing through it, muff, affect their 

 movements. From this caufe the value of the contrivance 

 will undoubtedly be diminifhed, but I think not done away. 

 I believe the famous pocket time-piece made about the year 

 1734-, by Emery of Charing-Crofs, for the Prefident Saron 

 at Paris, had its balance boxed up; but as I fpeak only from 

 recollection, it is quite as probable that the whole movement 

 was enclofed in a cap or cafe fliut up by a fecret catch. 



III. 



Analytical Experiments and Observations on Benzoin. By Mr, 

 William Bkanue'. Communicated by the Author .* 



Benjamin or 

 benzoes little 

 examined; 



Mr. Hatchetl' 

 experiments. 



Benzoin is ob- 

 from the 

 it y rax benzoe. 



Two kinds: 

 viz, benzoe 

 amjgdaloidesj 



The 



'E fubftance which forms the fubject of the following 

 experiments, and which is generally termed Gum-Benjamin or 

 Benzoes, may be enumerated, among thofe objects, which till 

 lately, have but little engaged the attention of chemifts. 



We are indebted to Mr. Hatchett for almoff. all that is as yet 

 known, as to the chemical properties of therefins, gum-refins 

 and balfams; and as the fubftance in queftion, had not been 

 examined by that gentleman, I was induced to make the fol- 

 lowing attempt. 



Benzoin is obtained by inciflons made in the tree called Styrax 

 Benzoe f, from whence the balfam flows, ope tree fcarcely 

 ever yielding more than three, or at the mofi four pounds. 



Benzoin is generally divided into two kinds; the one rs 

 formed of whitifh yellow tears, refembling almonds, united 



* The following experiments were made merely with a view of 

 afce'rtaining the etfe6tsof different menftrua on benzoin ; but as the 

 action of fome of the acids, &c. would have been much lefs in- 

 terefting, without a knowledge of the component parts of the bal- 

 fam, I was induced to make fdrhe analytical experiments, which, 

 though I fear they are by no means fo accurate as they ought to be, 

 will, I hope, ftill be found of fome ufe. 



f Dryander has given a defcription and drawing of this tree, vide. 

 Phil. Trans. 1787. p. 307. 



together 



