CART HAM US

or safflower (cart ham us tinct or i us), ( Carthame , Fr.; Färber distel , Germ.), the flower of which alone is used in dyeing, is an annual plant cultivated in Spain, Egypt, and the Levant. There are two varieties of it—one which has large leaves, and the other smaller ones. It is the last which is cultivated in Egypt, where it forms a considerable article of commerce. Cart ham us contains two colouring matters, one yellow and the other red. The first alone is soluble in water; its solution is always turbid: with re-agents it exhibits the characters usually remarked in yellow colouring matters. The acids render it lighter, the alkalies deepen it, giving it more of an orange hue: both produce a small dun precipitate, in consequence of which it becomes clearer. Alum forms a precipitate of a deep yellow, in small quantity. The solution of tin and the other metallic solutions cause precipitates which have nothing remarkable in them. The yellow matter of cart ham us is not employed; but in order to extract this portion, the cart ham us is put into a bag, which is trodden under water, till no more colour can be pre ed out. The flowers, which were yellow, become reddish, and lose in this operation nearly one half of their weight. In this state they are used. For extracting the red part of cart ham us, and thereafter applying it to stuff, the property which alkalies po e of di olving it is had recourse to, and it is afterwards precipitated by an acid. The proce of dyeing consists, therefore, in extracting the colouring matter by means of an alkali, and precipitating it on the stuff by means of an acid. It is this fecula which serves for making the rouge employed by ladies. As to this rouge, the solution of cart ham us is prepared with crystallised carbonate of soda, and it is precipitated by lemon juice. It has been remarked that lemons, beginning to spoil, were fitter for this operation than those which were le ripe, whose juice retained much mucilage. After squeezing out the lemon juice, it is left to settle for some days. The precipitate of cart ham us is dried at a gentle heat upon plates of stone-ware; from which it is detached and very carefully ground with talc, which has been reduced to a very subtile powder, by means of the leaves of shave-gra ( presle ), and succe ively pa ed through sieves of increasing finene . It is the finene of the talc, and the greater or le proportion which it bears to the cart ham us precipitate, which constitute the difference between the high and low priced rouges. Cart ham us is used for dyeing silk, poppy, nacarat (a bright orange-red), cherry, rose colour, and flesh colour. The proce differs according to the intensity of the colour, and the greater or le tendency to flame colour that is wanted. But the cart ham us bath, whose application may be varied, is prepared as follows: The cart ham us, from which the yellow matter has been extracted, and whose lumps have been broken down, is put into a trough. It is repeatedly sprinkled with cendres gravelées (crude pearl ashes), or soda (barilla) well powdered and sifted at the rate of 6 pounds for 120 lbs. of cart ham us; but soda is preferred, mixing carefully as the alkali is introduced. This operation is called amestrer . The amestred cart ham us is put into a small trough with a grated bottom, first lining this trough with a closely woven cloth. When it is about half filled, it is placed over the large trough, and cold water is poured into the upper one, till the lower becomes full. The cart ham us is then set over another trough, till the water comes from it almost colourle . A little more alkali is now mixed with it, and fresh water is pa ed through it. These operations are repeated till the cart ham us be exhausted, when it turns yellow. After distributing the silk in hanks upon the rods, lemon juice, brought in casks from Provence, is poured into the bath till it becomes of a fine cherry colour; this is called turning the bath ( virer le bain ). It is well stirred, and the silk is immersed and turned round the skein-sticks in the bath, as long as it is perceived to take up the colour. For ponceau (poppy colour), it is withdrawn, the liquor is run out of it upon the peg, and it is turned through a new bath, where it is treated as in the first. After this it is dried and pa ed through fresh baths, continuing to wash and dry it between each operation, till it has acquired the depth of colour that is desired. When it has reached the proper point, a brightening is given it by turning it round the sticks seven or eight times in a bath of hot water, to which about half a pint of lemon juice for each pailful of water has been added. When silk is to be dyed ponceau or flame colour, it must be previously boiled as for white; it must then receive a slight foundation of an not to, as explained in treating of this substance. The silk should not be alumed. The nacarats , and the deep cherry colours, are given precisely like the ponceaux , only they receive no an not to ground; and baths may be employed which have served for the ponceau , so as to complete their exhaustion. Fresh baths are not made for the latter colours, unle there be no occasion for the poppy. With regard to the lighter cherry-reds, rose colour of all shades and flesh colours, they are made with the second and last runnings of the cart ham us, which are weaker. The deepest shades are pa ed through first. The lightest of all these shades, which is an extremely delicate flesh colour, requires a little soap to be put into the bath. This soap lightens the colour, and prevents it from taking too speedily, and becoming unevenly. The silk is then washed, and a little brightening is given it, in a bath which has served for the deeper colours. All these baths are employed the moment they are made, or as speedily as po ible, because they lose much of their colour upon keeping, by which they are even entirely destroyed at the end of a certain time. They are, moreover, used cold, to prevent the colour from being injured. It must have been remarked in the experiments just described, that the caustic alkalies attack the extremely delicate colour of cart ham us, making it pa to yellow. This is the reason why crystals of soda are preferred to the other alkaline matters. In order to diminish the expense of the cart ham us, it is the practice in preparing the deeper shades to mingle with the first and the second bath about one fifth of the bath of archil. Dobereiner regards the red colouring matter of cart ham us as an acid, and the yellow as a base. His carthamic acid forms, with the alkalies, colourle salts, decomposed by the tartaric and acetic acids, which precipitate the acid of a bright rose-red. Heat has a remarkable influence upon cart ham us, rendering its red colour yellow and dull. Hence, the colder the water is by which it is extracted, the finer is the colour. Light destroys the colour very rapidly, and hitherto no means have been found of counteracting this effect. For this reason this brilliant colour must be dried in the shade, its dye must be given in a shady place, and the silk stuffs dyed with it must be preserved as much as po ible from the light. Age is nearly as injurious as light, especially upon the dye in a damp state. The colour is very dear, because a you sand parts of cart ham us contain only five of it. In preparing the finest rouge, the yellow colouring matter being separated by washing with water, the red is then di olved by the aid of alkali, and is thrown down on linen or cotton rags by saturating the solution with vegetable acid. The colour is rinsed out of these rags, di olved anew in alkalis, and once more precipitated by lemon juice. The best and freshest cart ham us must be selected. It is put into linen bags, which are placed in a stream of water, and kneaded till the water runs off colourle . The bags are then put into water soured with a little vinegar, kneaded till the colour is all expelled, and finally rinsed in running water. By this treatment the cart ham us loses nearly half its weight. 6633 cwts. of safflower were imported into the United Kingdom in 1835, of which 2930 cwts. were retained for internal consumption.