14 



THE CUBA REVIEW 



or to l)rigliti'n the tints {livon hy some other iiifiri'dicnt, or fo cfTcct tlic former :is ;i jjrcparative 

 to tlic latter. It is estcoined \or\ hif^hly, ln'caiiso it atTortis tlu- most (lural)lt' (Ich']) ri'il and 

 black dyes. The peculiar coloring jiriiiciplc called haomatoxyliii iCliiHHOC)) forms an orange 

 red solution with boiling water, becoming yellow as it cools, but recovering its formi>r hue when 

 heated. Alkali converts it first to purjile, then to violet, and lastly to l)rown, in which case 

 it seems to be decomposed. Metallic oxide unites with it, forming blue compounds. Gela- 

 tine throws down reddish floccidi. Stannous chloride renders it lilac. 



Logwood shavings yield their color to water and alcohol; the latter extracts it more readily 

 than water. The color of its dyes is red, inclining to violet or purjile. Its aciueous decoction, 

 left to it.self, becomes yellowish, and at length black. Acids turn it yellow; alkalies deepen its 

 color and give it a purple hue. The pro]ier shades ami colors are obtained by the use of alumi- 

 nous mordants. A blue color may be obtained from it by the addition of verdigris, but the 

 great consumption of logwood is for blacks, which are obtained by alum and iron bases, and of 

 any requisite degree of intensity. Alcohol extracts most of the active principles of this wood 

 and forrrs a deep colored tincture. ... 



Logwood Sticks on the Dock Ready for Export. 



Logwood was first shipi)ed to England and used for dyeing purposes soon after the acce.s- 

 sion of Queen Elizabeth, but the imskilled dyers of her time found that it yielded a fugitive 

 color, and so in b581 a law was passed prohibiting the importation and use of logwood in Eng- 

 land. Its use continued, however, on the continent and the German chemists soon discovered 

 a method for making a fast dye from logwood extract. Logwood then came into the English 

 markets under some feigned names until the law prohibiting its importation was repealed nearly 

 a hundred years after it went into effect. The preamble of the Act which was passed during 

 the reign of Charles II, declares that the ingenious industry of modern times has brought the 

 dyers of England the art of fixing the colors made of logwood, alias blackwood, so that, by 



