974 Transactions of the American Institute. 



shall confine myself to a few facts, which it has been my good fortune 

 to discover. 



One of the principal difficulties which existed in 1865, in applying 

 the blue, purple and aniline red on calico by printing, was the want 

 of a suitable compound which would render them insoluble in the 

 cloth during the process of steaming, and cause them to resist the 

 subsequent washing and soaping process. Albumen had been used 

 with success, but was very expensive. Mr. Perkin, of London, had 

 proposed the use of arsenite of soda in connection with the acetate 

 of alumina, both of which were mixed with the aniline color before 

 printing. This process met with very little success, owing to the 

 alkaline reaction of the arsenite of soda which precipitated most of 

 the acetate of alumina, thereby producing an insoluble color, which 

 would naturally only fix itself partially on the cloth. The difficulty 

 to overcome was to find a neutral arsenical salt, or a neutral solution 

 of arsenious acid. You all know how slightly the latter is soluble 

 even in boiling water. I had occasion to find that ordinary glycerine 

 dissolved its own weight of arsenious acid ; from this time the prob- 

 lem was solved. When one pound of white arsenic is added to a 

 pound of glycerine, and heated to boiling for about fifteen minutes, 

 the whole of the arsenic is dissolved, and the compound which is pro- 

 duced is an arsenical ether of glycerine. 



The color for printing either a red, purple or aniline blue is pre- 

 pared in the following manner : The crystallized color is dissolved in 

 the above arsenical ether of glycerine and thickened with starch ; the 

 color is then allowed to cool, and a certain quantity of acetate of 

 alumina is added. The color is then ready for printing, and is in an 

 entirely soluble state ; after printing, the cloths are steamed for thirty 

 minutes, when the following reaction takes place : Under the influ- 

 ence of the steam, the arsenical ether of glycerine is decomposed, 

 the acetic acid of the acetate of alumina is eliminated, and thereby 

 the insoluble arsenite of alumina formed in the cloth, holding the 

 coloring matter there in such an insoluble state that it will resist any 

 amount of washing, and a great amount of soaping. For the exact 

 proportions, I refer you to my United States patent, No. 63,084. 



On the aniline green I have very little to say to you. About the 

 middle of 1866, Prof. J. A. Wanklyn, of London, and myself, 

 obtained a beautiful green by the action (under pressure) of iodide 

 of isopropyl upon aniline red. All the aniline greens have been very 

 successfully used for dyeing silk and wool, upon which fibers they fix 

 themselves very readily. On cotton, however, up to the present time, 



