Louis Windmuller & Co. was a commission house that did not specialize in specific products, but rather dealt in general merchandise. Yesterday's post lists a few of the many different items they imported for their customers during the half century beginning in 1865.
The only image of the letter which I was able to locate is indistinct and quite a few words are hard to make out. Here's my guess as to its contents:
---------Singer, Witthaus & Co.
[illeg. cable addresses]24 & 25 Fenchurch Street E.C.
London, 17 April 1895
Messrs Louis Windmuller & RoelkerNew York
We confirm our response of 11th inst. & are in receipt of your favor of 5th inst.
We have succeeded in getting the little lot of Madagascar No21 for you @ 11/0 / sig HNC 22 bags / and are trying to get it off by the ss "Mohawk" sailing tomorrow.
We wired to you yesterday &mdash—
We have bought for you as demanded No21 1/6 We
think we can buy @ 1/½ No34.
Madagascar is scarce & very little lots that comes in are sold for high prices; there is nothing more to be had in the region of 1/0 [?]
The cheapest Mozambiques are we think No34 @ 1/1 perhaps 1/½, and No48 @ 1/2
Geuquela Ileggoes [?] ... can probably still be had at 1/9 per ... [?] & ... ... @ 1/7
We sold a few sample cases of "..." Guinea @ 1/½, but the bulk of No53 is still to be had. Some ... ... of not very good quality sold @ 1/6½Gambia No35 can probably
be had @ 1/6 & ...
No... @ 1/8 perhaps @ 1/7½.
The Madagascar No87 sold at 1/6½.Yours truly
Singer Witthaus & Co.
Here is an enlarged and enhanced image of the letter. Click to view full size.
My source was "sabob," a dealer in old documents. The sabob web page gives an image of the other side of the sheet containing the address and canceled stamp.
The document dealer describes the letter as coming from "Singer, Whitthaus & Co. London." A little searching shows that W. Singer and H.G. Witthaus (not Whitthaus) were in business at the address given on the letter: 24 & 25 Fenchurch Street, E.C. London directories list the building at that address as containing a variety of shipping offices. It's certain Singer and Witthaus were among them because their names appear at that address as subscribers to a book of London history that was published in 1891. Whatever the substances might be, it's apparent Louis Windmuller & Roelker were importing them via London.
It's clear from the letter itself that the document dealer meant "Mozambiques," not "Mozamiques." Searching the three African place names reveals little at first but a little digging gives some clues. At the time the letter was written, a type of resin used in making high quality furniture polishes, turpentines, and varnishes, was imported to the US from tropical countries. Some of the best came from Madagascar while lesser grades were obtained from Mozambique and Gambia. This isn't conclusive evidence that this resin was the subject of the letter, but I've failed to find alternatives and am pretty sure the evidence is good enough.
The resin is called copal. A full description of the many kinds and sources of copal is given in The Manufacture of Varnishes and Kindred Industries: Varnish materials and oil varnish making by John Geddes McIntosh, Achille Livache (Scott, Greenwood & son, 1908). The best copal was also the most rare. It was a fossilized product, dug from the earth in the vicinity of trees having the live resin beneath their bark layer.
The fossilized substance resembles amber and its hardness is a measure of its quality. A numeric system is used to designate the hardness/quality of a copal sample. The lower the number, the harder the sample. Thus Madagascar No. 21 would be harder and more expensive than No. 34, No. 48, No. 53, or No. 87, the numbers given in the letter from Singer & Witthaus.
The McIntosh book contains a drawing of the branch and fruit of the tree from which the Madagascar copal was obtained.
The Manufacture of Varnishes and Kindred Industries: Varnish materials and oil varnish making by John Geddes McIntosh, Achille Livache (Scott, Greenwood & son, 1908)
Tariff information surveys on the articles in paragraph 1- of the Tariff Act of 1913 and related articles in other paragraphs, United States Tariff Commission (Government Printing Office, 1921)
The term copal is applied rather indiscriminately to nearly all hard fossil or recent resins used in the manufacture of oil varnishes. These resins are used chiefly in the manufacture of varnishes, both oil and spirit, but principally the former. They are also used in the manufacture of enamel paints, and some of the lower grades in the manufacture of linoleum.Copal, article in wikipedia
The term copal was applied to the first resin imported into Europe from East Africa for the manufacture of oil varnishes. As other new resins were discovered which were suitable for the manufacture of oil varnishes, they were also termed copal, with a prefix which was usually the port of shipment or some other indicative term, for example, Manila copal. The term, therefore, has been applied indiscriminately to all hard fossil resins (amber excepted) capable of being used in the manufacture of oil varnishes, and would therefore include dammar and kauri, which are mentioned along with copal in paragraph 500 of the act of 1913. Copal is, then, a generic or class name which may be applied to all varnish gum-resins.
The copals may be classified according to age as fossil, and as recent, or raw. The fossil is usually of the most value for varnish manufacture. Copals are obtained in round tears, nodules, or flat pieces. Their hardness often varies inversely with the size, the smaller pieces being the harder, while the larger lumps are the softer. The hard copals are seldom as large as a man's fist, but the soft copals sometimes weigh between 60 and 120 pounds. Most of the copals have an agreeable fragrant odor. Hardness is one of the most important properties which a copal must possess to be suitable for the manufacture of high-grade varnishes.
The commercial copals may be classified, according to their hardness, as: (1) the hard copals, including the true copals of the east coast of Africa, typical of which is Zanzibar—also termed Bombay and Calcutta copal—Mozambique and Madagascar copal; (2) the medium or semihard copals, which include West African copals; (3) soft copals, including Kauri copal, Manila copal, and Borneo copal. Of these, those in group 1 are the true copals, derived from species of Trachylobium; those in groups 2 and 3 are those commercially termed copals because used for the same purpose as the original copals.
Copal was also grown in East Africa, (the common species there being Hymenaea verrucosa) initially feeding an Indian Ocean demand for incense. By the 18th Century, Europeans found it to be a valuable ingredient in making a good wood varnish. It became widely used in the manufacture of furniture and carriages. By the late 19th and early 20th century varnish manufacturers in England and America were using it on train carriages, greatly swelling its demand. ... In 1859 Americans consumed 68 percent of the East African trade, which was controlled through the Sultan of Zanzibar, with Germany receiving 24 percent. The American Civil War and the creation of the Suez Canal led to Germany, India and Hong Kong taking the majority by the end of that century. ... East Africa apparently had a higher amount of subfossil copal, which is found one or two meters below living copal trees from roots of trees that may have lived thousands of years earlier. This subfossil copal produces a harder varnish. Subfossil copal is also well-known from New Zealand, Japan, the Dominican Republic, Colombia and Madagascar. It often has inclusions and is sometimes sold as "young amber". Recent scientific datings demonstrated that the subfossil copal from Colombia and Madagascar is usually not older than about 200 years. Subfossil copal can be easily distinguished from genuine amber by its lighter citrine colour and its surface getting tacky with a drop of acetone or chloroform.Analysis of resins, balsams and gum-resins by Karl Dieterich (Scott, Greenwood & co., 1901)
East African copal. — Zanzibar (best and hardest kind, m.p. over 400° C.), Mozambique, Madagascar.Varnishes, lacquers, printing inks and sealing-waxes by William Theodore Brannt (H. C. Baird & co., 1893).
West African. — Young copal, from Sierra Leone; flint copal; Gaboon, Loango, Angola, Benguela, and Congo copal. [Gambian copal is West African of course.]
The East African copals are fossil, those from West Africa semi-fossil, the Kauri copals semi-fossil, the South American kinds recent; but nothing definite in this respect is known of the Indian copals.
The copals are distinguished in commerce according to colour—white, pale, or dark red; condition—natural, halfshelled, or shelled; and other peculiarities.
Copal, — The name copal is given to a number of resins which, in many respects, resemble amber, but differ much from one another. Some varieties of copal are mined like amber, but their properties show that they belong to a more recent period, and are, therefore, called recent fossil resins. Other varieties are directly obtained from the plants.Rubber, resins, paints and varnishes by Robert Selby Morrell (D. Van Nostrand Co., 1920)
Copal is found in commerce in very varying qualities. Usually a distinction is made between the copal from the East and West Indies, though a large number of the varieties are named after the locality from which they have been brought into market. Differing from all other resins in this respect, all varieties of copal are rough and very hard, melt only at a very high temperature, and can only be dissolved with great difficulty in the solvents ordinarily used for resins.
Copal is the most important of all resins used for the fabrication of fat varnishes, and for this reason it is considered necessary to describe more fully the principal varieties. Generally, copal is divided into two classes, namely, hard and soft copal.
Hard copal, East India copal, Zanzibar copal.—This copal is dug out of the ground, and comes from the east coast of Africa. It forms mostly flat, discoid pieces, from the size of a pea up to that of the hand. These pieces are either entirely colorless or yellow to a dark reddish-brown, and are transparent. The surface of this copal is peculiarly crusty, and it is so hard that it can be ground. Zanzibar copal has a specific gravity of 1.068. It resembles amber in so far that it only swells up, without actual solution, in alcohol, ether, and chloroform; it is, however, completely soluble in cajeput oil. When chewed between the teeth it forms a powder that does not cake together.
The supplies of fossil copals are limited and sooner or later the softer copals obtained from living trees will have to be utilized. It is stated that the supply of kauri copal will last for forty years at the present rate of output (U.S. "Commerce Report," No. 281, 1915). The resin is fossil from Dammara australis (a species of New Zealand pine). The gum obtained from living trees is known as young kauri and is softer and almost colourless. Young trees, when tapped, yield the resin, and it is not uncommon to find deposits of resin in old trees. For fresh sources of copals it is probable that the belt of country extending from Madagascar to Sierra Leone and possibly the Gambia will be the most promising. The fossil East African copals (Zanzibar, Madagascar, Mozambique, Lindi) are highly prized.Spons' encyclopaedia of the industrial arts, manufactures, and commercial products by Edward Spon et al (London, New York, E. & F. N. Spon, 1879)
Copal Resin. Copal is the concrete exudated juice of various trees. It is obtained either directly from the trees or as a fossil resin buried in the earth in their neighbourhood. Fossil copal is a highly-prized variety. Copal comes from the East Indies, South America, New Zealand, and both the east and west coasts of Africa. Some copals are soft; these are obtained from Sumatra, Java, Molucca, the Philippines, and Australia, and they are soluble in ether. The hard copals, which do not dissolve in ether until they have undergone a chemical change, come by way of Calcutta from Zanzibar and the African coast, and by way of Bombay from Madagascar, Mauritius, and Bourbon. Hard copal varies in properties somewhat with the origin of the different resins which are known by that name; but generally it is of a light-yellow or brown colour, without taste or smell, and has always been prized for varnishes.A Dictionary of applied chemistry, Vol. 4, by Thomas Edward Thorpe (Longmans, Green and Co., 1913)
The commerce in E. African copal is extensive. Zanzibar exports some 800,000-1,200,000 lb. annually. ... The exports of copal in British ships from the E. coast of Madagascar in 1872 were valued at 3466£. On the W. coast of Africa, which is still richer in copal than the S.E. coast, this resin is dug over a coast length exceeding 700 geogr. miles.----------
 For example, Lloyd's register of shipping (1901), The Export merchant shippers of London (1882), and THE MERCHANT SHIPPERS OF LONDON (1868).
 London city: its history--streets--traffic--buildings--people by William John Loftie (The Leadenhall press, 1891)
 Tariff information surveys on the articles in paragraph 1- of the Tariff Act of 1913 and related articles in other paragraphs, United States Tariff Commission (Government Printing Office, 1921)