CHEMICAL SCIENCE. 341 



Boussingault's process is as follows: A solution of arson ite of soda is 

 prepared, which contains fifty-seven grammes of arsenious acid in the litre. 

 Of this arsenical solution, three and a half litres arc taken and added to 

 twelve and a half litres of water. A hectolitre of corn is placed in a largo 

 tub, and thc.sc sixteen litres of mixture ai-c added, the corn being continually 

 stirred. In about an hour the whole of the liquid is absorbed, and the grain 

 is then dried. It is, of course, necessary to exercise extreme care in using 

 the arsenical solution, and it is well to color it strongly by the addition of 

 sulphate of iron and prussiatc of potash, so that its presence would be readily 

 betrayed. 



This steeping is not an unprofitable aifair, for it first effectually preserves 

 the harvest, and, secondly, by killing the vermin which might devour it, con- 

 verts them into useful manure. 



ON SOME PRINCIPLES CONCERNED IN DYEING. 



M. Kulilmann having remarked that when eggs were dyed, some of them 

 took colors better than others, and that this fixation of the color took place 

 without any mordant, was led to suppose that, in these cases, the fixation 

 was not due to the calcareous salt, of which the egg-shell is formed, but to 

 the azotized coating upon its surface. This supposition was verified by ex- 

 periment. As the coating of the egg-shell is very analogous to albumen, 

 this latter substance, coagulated by heat, was tried separately in baths of 

 Brazil wood, etc., and its absorbing power thus shown. M. Kuhlmann then 

 tried the use of this substance, for the purpose of increasing the absorbing 

 power of different tissues ; he obtained very favorable results with cotton, 

 less distinct with silk, scarcely perceptible with wool ; these trials were made 

 with Brazil wood, madder, and campeachy wood. After albumen, he tried 

 with the same success milk and caseum, which may be coagulated on the 

 surface of the tissues by means of an acid. Milk, especially alone or in 

 connection with mordants, gave the cotton very full colors. He experi- 

 mented also upon gelatine coagulated by tannin, and obtained results^ 

 although feeble, without mordants. He also showed that albumen may- 

 serve as a medium for precipitating upon stuffs, metallic oxides, with which 

 it forms insoluble compounds ; in dyeing, stuffs impregnated with these 

 compounds, absorb colors with more ease than if they had been prepared 

 with albumen, or with the same metallic salts alone. Analogous results 

 were obtained with tannin-gelatine. L'InstituL., 2Gth Nov. 



ON THE PRESENCE OF FLUORINE IN THE BLOOD. 



M. Nickles, in a communication to Silliman's Journal, states that having 

 established the much-contested question of the existence of fluorine in the 

 bones, " I next looked for it in the blood the onl v means bv which it could 



f V 



penetrate into the osseous tissues. I have found there notable proportions, 

 not only in human blood, but also in that of several Mammalia, (as the 

 sheep, ox, dog,) and several birds (the turkey, duck, goose, hen)." 



29* 



