AMERICAN INSTITUTE. 3T5 



heen to a great extent satisfactoril}'' realized in commercial practice. Messrs. 

 Perkins & Chiircli have obtained from the alkaloids of coal tar, and one 

 from napthaline, several blue coloring substances of great value. They 

 are named by the discoverers, Nitroso-phenyline and Nitroso-napthyline. 

 They are beautiful purple-blue colors ; some of them have been success- 

 fully fixed on silk. One, in particular, fairly rivals the delicate orchil color, 

 or that made from lichens, while it has the great advantage of resisting the 

 action of light. 



The process is dissolving in water the sulphates of aniline, of cuminine, 

 •of taluidine, adding ^n-chromate of potash sufficient to neutralize the sul- 

 phuric acid in these sulphates. The whole is left to stand for twelve hours, 

 when a brown substance is precipitated, which is washed with coal-tar nap- 

 tha, and then dissolved in methylated spirits. This solution, with the 

 addition of a little tartaric or oxalic acid, forms the dyeztig liquor. 



Messrs. Low and Calvert have conjointly produced from coal tar, colors 

 resembling safflower pinks and cochineal crimsons ; and on a piece of calico, 

 mordanted for madder, all the various colors and shades derived fron the 

 madder root, violet, purple, chocolate, pink and red, can be obtained in 

 this way> The safflower imitation stands the action of soap and light ; the 

 real, of course, does not. 



Guano has produced in the laboratory of the French chemist, M. de 

 Pouilly, a very beautiful crimson called murexide, (like the murex Tyri m 

 purple,) and has fixed it on silk by dipping the silk in a concentrated soi\w 

 tion of bi-chloride of mercury, mixed with the murexide, squeezing th,^ 

 silk well and hanging it in the air, a magnificent crimson insoluble com- 

 pound is thus fixed on the silk. 



Wool Dyed Green rvith Grass. — Mr. Schlumberger has fixed the green 

 ■thIoroj)hyUe of grass and leaves permanently on wool. 



HOMES TO BE HAPPY MUST BE HEALTHY. 



Mr. John Johnson. — -Volumes have been written by learned and scien- 

 tific men, anxious for the public good, not only on the advantages of ven- 

 tilation, but on the absolute necessity of it for the preservation of health. 

 Practical men come to the aid of science, and invent contrivances for 

 ■efi"ecting the object ; and those of real utility can only be considered, which 

 admit of being adapted to our present mode of constructing our dwellings, 

 halls, &c., having due regard to the cost as well as efficiency. The phy- 

 sician knows too well, the difficulties which are in his path in his daily 

 practice, where ventilation cannot be had, or where it can be, and is not 

 effected ; fresli, pure air, b-eing more important, even, than unwholesome 

 food. At any rate, a time must come when fresh air will be so regarded — 

 the latter being the invisible one, we know ; but, facts well considered, the 

 result will prove this of the first importance, and will stand in the scale 

 higher than the visible, tangible, necessaries of life. 



The invisible agent, then, of health or disease, demands, like other natu- 

 ral agents, to be brought under proper management and control, in order 



