CONIFERS. 



SILVA OF NORTH AMERICA. 



65 



to work, Kable to wind-shake and splinter, and not durable when exposed to the air. It is light brown 

 tinged with red or often nearly white, with thin somewhat darker sapwood, and contains broad 

 conspicuous bands of small summer cells and numerous thin medullary rays. The specific gravity of 

 the absolutely dry wood is 0.4239, a cubic foot weighing 26.42 pounds. It is now largely manufactured 

 into coarse lumber employed for the outside finish of buildings ; it is also used for railway-ties, and 

 occasionally for water pipes.^ Two varieties, red and white hemlock, which, however, appear to be 

 produced under precisely similar conditions, are recognized by lumbermen. 



The astringent inner bark affords the largest part of the material used in the northeastern states 

 and Canada in tanning leather,^ and from it is prepared a fluid extract sometimes employed medicinally 

 as an astringent.^ Canada pitch, an opaque resin obtained from the wood, was formerly used in 

 medicine,* and from the young branches oil of hemlock is distilled.^ 



This Hemlock was first described by Plukenet in 1691 ^ from a tree cultivated in his garden In 

 London by Bishop Compton,^ to whom it had been sent from Virginia by John Banister.^ Its 

 value had been recognized, however, much earlier by the settlers of Canada and New England, and 

 Pierre Boucher ^ and Josselyn ^° extolled its virtues soon after the middle of the seventeenth century. 



^ See Am. Jour. Pkarm. xxxiv. 377. 



2 The bark of Tsuga Canadensis^ which varies considerably in 

 the amount of tannin it contains, is used in enormous quantities 

 in the manufacture of heavy leather, and also in the production of 



the finer grades of leather, when it is mixed with Oak bark to 

 modify the red color of leather tanned entirely with Hemlock 

 bark. An extract of the bark is used by tanners instead of the 

 bark itself, to strengthen their bark liquors. It is also employed 

 by dyers to modify the shades of logwood coloring, especially 

 when copper sulphide is used as a mordant. (See Bastin & 

 Trimble, Am. Jour, Pharm. Ixix. 94. See, also, for the tannin of 

 Hemlock bark, Procter, Text-book of Tanning, 31. — ■ Mulligan & 



Dowling, Chemical Gazette, xvii. 430. — Mafat, Bull. Soc. Indus- 

 trielle de Mulkouse, Ixii. 130. — Olivier, Recherches pour servir a 

 VHistoire Naturelle, Chimique et Industrielle du Hemlock.') 



2 See Johnson, Man. Med. Bat. N. Am. 259. — Millspaugh, Am. 

 Med. PI. in Homoeopathic RemedieSy ii. 164, t. 164, — Parke, Davis 

 & Co., Economic Mat. Med. ed. 2, 93. 



* Canada pitch, formerly often known as Hemlock resin, is an 

 opaque brittle resin which is obtained from Tsuga Canadensis by 

 boiling the wood and bark from around knots with water, and 

 skimming off the resin which rises to the surface. It is also 

 said to be obtained from incisions made in the trunks of living 



trees in the same manner that turpentine is obtained from Pine- 

 trees. Canada pitch was formerly used as a substitute for the 

 similar Burgundy pitch in the manufacture of medical plasters, 

 and was collected in considerable quantities. It has now, how- 

 ever, disappeared from the United States Pharmacopceia, and is 

 replaced by asphalt or rubber in the manufacture of medical plas- 

 ters. (See Ellis, Jour. Phil. College of Pharmacy, ii. 18 [On Hem- 

 lock Resin]. — Stearns, Am. Jour. Pharm. xxxi, 28 [Medical Plants 

 of Michigan']. — Bentley & Trimen, Med. PI. iv. 264, t. 264. — U. 

 S. Dispens. ed 17, 1174. — Bastin & Trimble, I. c. 91.) 



5 Oil of Hemlock, which is contained in the leaves of Tsuga 

 Canadensis, and appears to be identical in chemical composition 

 with the volatile oil of Black Spruce leaves, is obtained in winter 

 by distilling in water in small portable copper stills and worms 

 set up in the woods the branches of Tsuga Canadensis cut up into 

 small pieces. Eight pounds of branches yield on an average an 

 ounce of oil, or about three pints to one running of a still, which 

 occupies from thirteen to twenty-four hours. (See Stearns, I. c. — 

 Bertram & Walbaum, ^rcSiy. de Pharm. ccxxxi. 294. — Hunkel, 

 Pharmaceutical RevieWj xiv. 34. — Bastin & Trimble, I. c. 90.) Oil 



of Hemlock is used in considerable quantities as a flavoring and 

 for disinfecting purposes, and occasionally in medicine to produce 

 abortion. 



^ Abies minor pectinatis foliis, Virginiana, conis parvis, subrotun~ 

 disj Plukenet, Phyt. t. 121, f. ; (excl. syn. Hernandez) Aim. Bot. 

 2. — Bay, Hist. PL iii. Dendr. 8. — Miller, Diet. No. 3. — Duba- 

 mel, Traite des Arbres, i. 3. 



Abies foliis solitariis confertis obtusis memhranaceis, Clayton, Fl, 

 Virgin. 191. 



7 See i. 6. 



^ See i. 6. 



® '* II y a encore une autre espece qu I'on appelle Prusse; ce 

 sont ordinairement de gros arbres qui ont trente ou quarante pieds 

 de haut sans branches : ils ont une grosse ^corce et rouge: ce bois 

 ne pourrit pas si facilement que les autres ; c'est pourquoy on 

 s'en sert ordinairement pour bastir. Ce qu*il y a de mal dans ce 

 bois, c'est qu'il s'en trouve quantite de rouiUe, ce que le fait 

 rebuter. De celuy-lk il en vient par tout, en bonne et mauvaise 

 terre ; il ne produit point de gomme." (Histoire Veritable et 

 Naturelle des Moeurs et Productions du Pays de la Nouvelle-France 

 vulgairement dite le Canada, ed. 3, 51.) 



10 " Then she Playstered it with the Bark of Board Pine, or Hem- 

 lock Tree, boyled soft and stampt betwixt two stones, till it was 

 as thin as brown Paper, and of the same Colour, she annointed the 

 Playster with Soyles Oyl, and the Sore likewise, then she laid it on 

 warm, and sometimes she made use of the bark of the Larch Tree,''^ 

 (Josselyn, New England's Rarities^ 62.) 



" Hemlock Tree, a kind of Spruce, the bark of this Tree serves 

 to dye Tawny ; the Fishers Tan their Sails and Nets with it. 



" The Indians break and heal their Swellings and Sores with it, 

 boyling the inner Bark of young Hemlock very well, then knocking 

 of it betwixt two stones to a Playster, and annointing or soaking it 

 in Soyls Oyl, they apply it to the Sore : It will break a Sore Swell- 

 ing speedily." (Josselyn, New England^s Rarities, 64.) 



" The Hemlock-Tree is a kind of spruce or pine ; the bark boiled 

 and stampt till it be very soft is excellent for to heal wounds, 

 and so is the Turpentine thereof, and the Turpentine that issueth 

 from the Cones of the Larch-tree (which comes nearest of any to 

 the right Turpentine) is singularly good to heal wounds and to draw 

 out the malice (or Thorn as Helmont phrases it) of any Acb, rubbing 

 the place therewith, and stro wing upon it the powder of *S'a^e-leaves." 

 (Josselyn, An Account of Two Voyages to New England, p. 67.) 



