56 THE ALUMNI JOURNAL 



them nice and soft, were to lay a sweet-smelling flower on Scheele's 

 grave, the hanging gardens of Babylon would be outdone. 



The remaining years of Scheele's life were devoted to the prod- 

 ucts from the acid saccharine fruits. He thus completed a cycle, 

 for his first and last discoveries were made in the wide domain of 

 the vegetable acids. 



He extracted Citric Acid from lemons by a process still used. 

 The boiling juice is first completely saturated with finely powdered 

 Calcium Carbonate, and the resulting precipitate of Calcium Citrate 

 allowed to subside When it is repeatedly washed with water and 

 decomposed by dilute Sulphuric Acid, an insoluble Calcium Sul- 

 phate separates out, and the coveted Citric Acid remains in solu- 

 tion. This is then carefully concentrated in leaden boilers until a 

 pellicle begins to form, when it is transferred to other vessels to 

 cool and crystallize. Twenty gallons of lemon-juice should yield 

 about ten pounds of the crystallized Citric Acid. 



Though Citric Acid is usually obtained from lemons or limes, it 

 exists also in the juice of the gooseberry, strawberry, raspberry, 

 cranberry, currant, cherry, orange, and of course many other fruits. 



The world is small nowadays, and to make Citric Acid for com- 

 mercial purposes, we get lemon-juice from Sicily, lime-juice from 

 the West Indies, and bergamot-juice from the Calabrian coast. 

 Citric Acid has been prepared artificially by Grimaux and Adam, 

 who started with Glycerin, produced Chloro- and Cyano-derivatives, 

 and finally got Citric Acid itself. Recently, Carl Wehmer has dis- 

 covered that sugar solutions, if exposed to the action of certain 

 mould fungi, become transformed into Citric Acid, and it is thought 

 that this method of manufacture may replace the extraction from 

 lemon-juice. 



In several of the world's Pharmacopoeias, Citric Acid has for its 

 immediate neighbor another of Scheele's discoveries — Gallic Acid. 

 Gallic Acid exists free in nutgalls, in the leaves of the bearberry, 

 in the root-bark of the pomegranate, and other vegetable sub- 

 stances. It is often found coml)ined as a glucoside. It is prepared 

 from the tannin of nutgalls, either by the action of dilute acids or 

 by the change due to mould growths. Gallic Acid is used in 

 chyluria, pyrosis, diarrhea, dysentery, tabes, rickets, scarlatinal al- 

 buminaria, hematemesis, menorrhagia, in checking the night-sweats 

 of phthisis and other pathological conditions. 



Malic Acid is likewise in Scheele's Document of Discoveries. It 

 is a deliquescent crystalline compound, with a pleasant acid taste, 

 and occurs in the juice of most sour fruits. The most interesting 

 characteristic of Malic Acid is the fact that it furnishes us with a 



