380 Miscellanies. 



the exhaustion is complete- A premium of three hundred francs 

 was awarded to the inventor. — Rev. Encyc. Nov. 1832. 



DOMESTIC ECONOMY AND THE ARTS. 



1 ♦ Experiments on coloring matter for the purpose of dyeing or 

 printing. — M. Persoz, manipulator to the chemical courses in the 

 College of France, announced to the Academy that he had discovered 

 in a great number of coloring substances, such as indigo, madder, coch- 

 ineal, lac, quercitron, Brazil wood, &ic, a commom properly, the knowl- 

 edge of which, enables him to extract, by the same process, the color- 

 ing portion of these substances. Thenard, D'Arcet, and Chevreul, ap- 

 pointed by the Academy to judge of the effect in dyeing, of the color- 

 ing matter prepared by M. Persoz, subjected them to the following 

 experiments. M. Persoz having taken two pieces of cotton cloth, on 

 which designs had been impressed by a mordant, for red, rose and violet 

 from madder, colored them for a comparative trial by his preparation 

 and common madder. The cloth, when taken from the bath, was 

 passed through hot soap suds. The specimen colored with the new 

 preparation was incontestibly of a purer rose red color than that 

 by the usual process. Besides this, the ground of the first specimen 

 was almost white, while that of the second was tinctured with the 

 reddish color which the madder had given to the portion of the cloth 

 which had not received the mordant. M. Persoz also showed the 

 commissioners a blue preparation from indigo, which he applied to 

 cotton, and which sustained the action of a boiling solution of potash. 

 Having thus proved the solidity of the colors of these specimens, the 

 committee did not hesitate, although ignorant of the process of M. 

 Persoz, to propose to the Academy to encourage this chemist to 

 pursue researches which may be of great importance to manufactur- 

 ing industry. — Rev. Encyc, Nov., 1832. 



i 



2. Blowing of glass. — The effort of the lungs requisite to this 

 process is incompatible with a weak state of those organs, and the 

 exercise is sometimes attended with injurious consequences. A 

 workman whose name is Ismael Robinet has invented what he calls 

 an air pump, an instrument by which air is forced through the tube 

 with greater power than that of the lungs. This has been found to 

 be very advantageous, especially in moulding, the workmen being 

 enabled to force the glass more perfectly into the crevices and devices 

 of the mould, and thus not only to blow larger pieces and employ 



