272 ANNUAL OF SCIENTIFIC DISCOVERY. 



a piece of copper half the size of a piifs head could easily be 

 oblaiued. Charcoal also yields a cupreous ash, and as both pa- 

 per and charcoal are made use of in the analyses spoken of, it 

 might be sui^gested tluit the copper of tliese substances got into 

 the analyzed materials, where, of course, they would have been 

 found. Yet this reaction has its limits. If it is possible to detect 

 copper in 10 grains of paper, and in 100 grains of charcoal, it is 

 not possible to lind it in 0.2o graius of paper, or 0.1 grain of char- 

 coal, which are the quantities used in each analysis. Besides, cop- 

 per has been discovered in animal tissues without the use of either 

 paper or charcoal. The above-mentioned facts are certainly not 

 without importance to physiology, judicial medicine, and phar- 

 macy, but it is to be hoped, that, in following them uj), more light 

 will be thrown upon this interesting topic. — ticientijlc American: 

 translation from Aus der Natur. 



UNHEALTHFULNESS OF IRON STOVES. 



Considerable discussion having arisen as to the permeability of 

 cast iron to gases, and to their morbific efleet in ill-ventilated 

 rooms (see " Annual of Scientific Discovery" for 18G9, p. 12G), the 

 conclusions of Gen. Morin, as given in a report to the French 

 Academy, will be read with interest. 



The experiments extended over a year, and were performed at 

 the " Conservatoire des Arts et Metiers," in Paris, being termi- 

 nated in February, 18G9. 



His conclusions are as follows : — 



1. In addition to the immediate and srrave inconveniences 

 arising from the facility with which stoves of the orJinary metals 

 attain a red heat, cast-iron stoves, at a dull red heat, cause the 

 development of a determinate but very variable amount of car- 

 bonic oxide., a very poisonous gas. 



2. A similar development takes place, but in a less degree, in 

 sheet-iron stoves raised to a red heat. 



3. In rooms thus heated, the carbonic acid naturally contained 

 in the air, and that derived from respiration, maybe decomposed, 

 and produce carbonic oxide. 



4. The carbonic oxide may arise from several different and 

 sometimes concurrent causes, as, the permeability of the iron to 

 this gas, which passes from within outward ; the direct action of 

 the oxygen of the air upon the carbon of the iron heated to red- 

 ness; the decomposition of the carbonic acid in the air by its 

 contact with the heated metal, and the intiuence of organic dust 

 naturally contained in the air. 



5. The effects observed in a room lighted by four windows, 

 and two doors, one of which is frequently opened, would be 

 made manifest and grave in ordinary rooms, without ventilation, 

 in consequence of the presence and decomposition of various 

 kinds of organic dust therein present. 



6. Consequently, stoves and heating apparatus in cast or sheet 

 iron, without interior linings of fire-bricks, or other refractory 



