XXXIV. THE MOUNTAIN SUMACH. 503 



turn cider into vinegar. The acid is found to be the bi-malate 

 of lime ; and with a microscope, the crystals may be seen min- 

 gled with the down on the outside of the berries. 



Prof. Wm. B. Rogers* recommends the following process for 

 obtaining it perfectly pure : — " A quantity of hot rain water or 

 distilled water is poured over the berries in a clean wooden or 

 earthen vessel. After allowing the berries to macerate for a day 

 or two, the liquid is poured off and evaporated carefully in an 

 earthen or porcelain dish, until it becomes intensely acid. It is 

 now filtered through animal charcoal or bone black, repeatedly 

 washed with muriatic acid. The liquid passes through almost 

 colorless, having only a slight amber tint. If the evaporation 

 has been carried sufficiently far, a large deposit of crystals will 

 form in a few hours. The liquid being poured off and further 

 reduced by evaporation, an additional crop of crystals may be 

 obtained, and in this way nearly all the bi-malate may be sepa- 

 rated. The salt thus procured will often be slightly tinged with 

 coloring matter, in which case it should be re-dissolved in hot 

 water and crystallized anew. It is then perfectly pure." 



The berries are also used in dyeing and give their own color. 

 Kalm says, that the branches boiled with the berries, afford a 

 black, ink-like tincture.-f- 



The pith of this, as of the other sumachs, is very consider- 

 able. Of the wood, the outermost circles are white, the inner- 

 most of a yellowish-green. The wood burns well and without 

 much crackling. 



Sp. 3. The Mountain Sumach. Dwarf Sumach. R. copalllna. L. 



A beautiful plant, growing on dry, rocky or sandy hills or 

 road-sides, usually to the height of three to five feet, but some- 

 times, in favorable, protected situations, to eight or ten, some- 

 times eighteen or twenty feet, and four or five inches in diameter. 



Branches and common footstalks of the leaves and flowers 

 pubescent, dotted with brown. Leaflets 9 to 21, nearly sessile, 

 oval-lanceolate or oblong-lanceolate, unequal at base, rounded 

 below often acute above, acute at the end, — the terminal leaflet 



* In Silliman's Journal, Vol. XXVII, p. 295. t Kalm's Travels, I, 75. 



