698 Transactions of the American Institute. 



RED LEAD. 



Barton produces red lead by heating the oxide of lead to red- 

 ness with the nitrate of soda, or by heating at the same tempera- 

 ture a mixture of 1,894 parts of sulphate of lead, 665 parts of 

 carbonate of soda, and 177 uarts of nitrate of soda. The resulting 

 mass is to be washed. 



TO CLARIFY TURBID WATER. 



Turbid water, holding any kind of earthy substances, is rendered 

 fit to drink in from seven to fifteen minutes, if to each litre there 

 be added 4-lOOths of a gramme of finely powdered alum, or three- 

 quai'ters of a pound to every ton of water, care being taken to 

 agitate the liquid when the alum is introduced. 



DOUBLE SESQUICHLORroE OF IRON AND SODIUM. 



F. Landauer has produced this new compound by the action of 

 hydrochloric acid on artificial ultramarine. By writing upon paper 

 wuth the solution, and afterward warming it, the letters become 

 black, just as in the case of some sympathetic inks, but the writing 

 does not disappear by the action of water. 



MOLTING OF FISHES. 



M. Baudelot, in a paper read before the French Academy of 

 Sciences, says tubercles are often observed on the sides of fishes, 

 accompanied by the falling oflf of the scales; these were sometimes 

 considered characteristic of a new species of fish. They are, how- 

 ever, periodical, and found only at certain seasons of the year, thus 

 constituting a true molting. 



POISONING BY PHOSPHORUS. 



M. Dybkowsky, in a recent memoir, states that the poisonous 

 action of phosphorus is entirely due to the formation of phospho- 

 reted hydrogen gas, which, in passing into the blood, rapidly com- 

 bines with the oxygen present. Hence, he concludes that death 

 from phosphorus is nearly equivalent to death by asphyxia. 



TO DETECT CHICCORY. 



Dr. Draper gives, m the Philosophical Magazine, the means of 

 estimating more or less accurately the amount of chiccory present 

 in some kinds of ground cofiiee. He uses a tube, having its lower 

 end drawn out so as to be of smaller diameter, which is graduated 

 into four equal divisions. Chiccory and other roots sink in water, 

 while cofiee floats. By means of this tube the proportion of the 



