178 



tabvilar crystals, inodorous and tasteless, very little soluble in 

 water, better in alcohol and in ether; form with acids colourless, 

 neutral, crystallisable, bitter salts. 



Primrose Stearoirteil. Passes over with the water in the 

 distillation of the root of Prinnila Auricula and subsides in the 

 turbid distillate. Has a strong and peculiar, pleasant odour; its 

 alcoholic solution imparts a deep-red colour to solutions of iron. 



Prilliulill. Indifferent, crystalline substance of the root of 

 Primula veris. Treat the aqueous and well-dried extract of the 

 root repeatedly with alcohol of 90°/^, evaporate the sjjirituous 

 liquids slowly, press the separated crystalline mass between 

 blotting paper, redissolve in alcohol, digest with carbonate of lead, 

 filter and let crystallise.— Forms colourless needles or lustreless 

 grains, inodorous and tasteless, neutral, readily soluble in water, 

 also in alcohol (but more in aqueous than in anhydrous), not in 

 ether, fuses by heat and decomposes in higher temperatures. Is 

 not precipitable by metallic salts. 



[Dr. L. Mutschler states, that according to his researches 

 Primulin is identical with Cyclamin, and appears to be widely 

 distributed among the order of Primulacese. He also believes 

 that Cyclamin and Primulin may probably be identical with 

 Saponin.] 



Prophetin. See Ecbalin. 



Proilioilie Acid = C« H5 O3 + HO. Has been found as yet 

 only occasionally in the aqueous distillates of a few vegetable 

 parts (Flores Millefolii, (fcc), but is probably more >videly 

 distributed. Its presence in such a distillate is recognisable 

 to some extent by its odour, resembling butyric and pyro-acetic 

 acids. By saturating this distillate with cai'bonate of soda, 

 drying and mixing the salts with sulphuric acid, the said odour 

 becomes very striking, and on heating the salt by itself, the odour 

 of alkarsin is evolved. The acid, after being isolated from the 

 concentrated solution of the Propionate of soda by means of sul- 

 phuric acid, floats upon the surfiice in the form of an oily liquid 

 and disappears only on addition of more water. The Propionates 

 are unctuous to the touch, and are all soluble in water. The Pi-o- 

 pionate of soda, dried at 100°, is anhydrous and contains 64'87 % 

 acid. 



Protein Snbstances. In the vegetable and more so in the 

 animal kingdom there exist, either dissolved or as solids, a number 

 of amorphous, not volatile, inodorous and tasteless, nitrogenised, 

 indifierent substances, which exhibit a great analogy in their com- 

 position and in their genei'al })roperties. Being originally formed 

 in the vegetable organism, they from thence are introduced by the 

 food into the animal body, and are found there again M'ith little or 



