VOL. LVII.] PHILOSOPHICAL TRANSACTIONS. 479 



XLIX. An Account of some Neutral Salts made with Vegetable Acids, and with 

 the Salt of Amber; which shows that Vegetable Acids differ from one another; 

 and that the Salt of Amber is an Acid of a Particular Kind, and not the same 

 with that of Sea-salt, or of Vitriol, as alleged by many Chemical Authors. 

 By Donald Monro, M.D., Physician to the Army, &c. F.R.S. p. 47Q. 

 Suspecting from the taste and smell of the vegetable acids that they differed 

 materially one from another. Dr. D. M. was induced to prepare neutral salts 

 from them, and to examine the forms of the saline crystals thus obtained. He 

 found in many instances a considerable difference in the forms of these crystals, 

 showing that his conjectures on this subject had been well founded. ' ■ 



He treats, 1. Of Neutral Salts formed with Native Vegetable Acids. 



2. Of Neutral Salts formed with Fermented Vegetable Acids, 



3. Of Neutral Salts formed with Distilled Vegetable Acids, 



4. Of Neutral Salts formed with Flowers of Benzoin and Salt of Amber, 

 Under § I he describes the Neutral Salts formed with Native Vegetable Acids 



and the Fossil or Mineral Alkali ; viz, 1 with the Acid of Lemons ; 2, with the 

 acid of Limes ; 3 and 4, with the Acid of Seville Oranges and of Peaches ; 5, 

 with the Acid of Currants ; 6, with the Acid of Gooseberries ; 7, with the Acid 

 of Apples; 8, with the Acid of Wild Sorrel ; 9, with the Acid of Tamarinds; 

 10, with the Acid of Plums; 11, with the Acid of Mulberries ; 12, with the 

 Acid of Grapes. 



Under § 11, he describes the Neutral Salts formed with Fermented Vegetable 

 Acids and the Fossil Alkalies; viz. I and 2, with Common Wine and Distilled 

 Vinegar; 3, with Crystals of Tartar; 4, vnth the Acid of Verjuice of Apples; 

 5, with the Acid of Perry. 



Under § iii. he describes the Neutral Salts formed with Distilled Vegetable 

 Acids and the Fossil Alkali; viz. 1 with the Acid of Guaiac Wood; 2, with the 

 Acid of Fir-wood ; 3, with the Acid of Honey, Respecting this last, Dr, M. 

 says that he prevailed with Mr, Winter, brother-in-law to Mr, Heineken, apo- 

 thecary, to distil 4 or 5 lb. of honey in a retort ; at first Mr, W, imagined that 

 Dr, M, only wanted the watery phlegm, which has been called by the name of 

 the spirit of honey, and stopped the distillation before the acid came over; but 

 having distilled a 2d quantity, he procured him about 6 oz, of a very acid liquor, 

 which he mixed with the phlegm or spirit he first brought him ; he then satu- 

 rated the whole with the fossil alkali, filtered and evaporated the liquor to a 

 pellicle. After it had sto(xl all night in a cool place, he found the pellicle to be 

 composed of a yellow, bitter, saltish, mucous and oily matter; below which was 

 a dark purplish liquor, which he poured into a tea cup, and there remained at 

 the bottom of the stone gallypot, in which the evaporation had been performed, 

 a yellow concreted matter, somewhat of the appearance of yellow wax, mixed 



