562 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



remaining in them for any considerable length of time, and 

 various devices have been adopted, so that, while retaining 

 the use of lead pipe, to prepare it in such a way as to render 

 it harmless. A lining of block tin has been a favorite ar- 

 rangement for this purpose ; but a much simpler one has re- 

 cently been suggested, which, it is said, is entirely satisfac- 

 tory. The process consists essentially in converting the in- 

 terior surface of the pipe into an insoluble sulphide of lead, 

 the result of which is that water flowing through it will be 

 as free from contamination as if in contact with glass. This 

 is accomplished by passing a strong solution of the sulphide 

 of potassium and sodium through the pipe at a temperature 

 of about 212 Fahrenheit, and allowing it to act upon the 

 metal for from 10 to 15 minutes. The Boston Journal of 

 Chemistry ', in commenting, upon these statements, claims the 

 credit of an earlier announcement of a similar treatment, 

 which consists in dissolving one pound of sulphide of potas- 

 sium in two gallons of water, and allowing it to remain in 

 the pipe for twelve hours, or until the inside is thoroughly 

 blackened. 8 A, September 1,168. 



POISONOUS ANIMAL EMANATIONS. 



In a late communication of M. Chauveau to the Academy 

 of Sciences of Paris upon the pretended virulent volatile em- 

 anations, and upon the condition in which the virus is thrown 

 into the atmosphere by subjects laboring under contagious 

 maladies, he endeavors to show that the contagious peculiar- 

 ity in virulent humors does not depend upon the substances 

 dissolved, but upon the solid particles which these humors 

 hold in suspension. From this he concludes that the forms 

 of virus improperly called volatile are incapable of spread- 

 ing into the atmosphere, and that the elements endowed with 

 virulence can exist in the atmosphere only in the condition 

 of emanations from diseased subjects ; that is to say, that 

 they assume the form of solid particles held in suspension. 

 3JB 9 XUL 7 July 27,728. 



TOISONING BY CHARCOAL FUMES. 



From observations made by Drs. Eulenberg and Vohl, of 

 Cologne, it would appear that the poisonous carbonic oxide 

 gas is generally to be found in common charcoal, and that it 



