258 ANNUAL OF SCIENTIFIC DISCOVERY. 



would find no mercury in the organs. They would, however, commit 

 a great error should they conclude that there had been no attempt to 

 poison. This error is impossible when we are acquainted with the 

 above-named facts. 



C. A workman in a white lead factory died two months after 

 having ceased to manipulate saturnine preparations. In his organs the 

 chemist finds lead. Had this lead been given criminally, or does it 

 proceed simply from the compounds absorbed by the workman in the 

 factory ? To give a satisfactory reply to this question, the operator 

 must carefully study the development and the symptoms of the malady 

 which preceded the death, and combine these facts with those furnish- 

 ed by the study of elimination. 



It is rational to make a comparison of the process hitherto proposed 

 for the detection of lead, copper, and mercury contained in organic 

 compounds, before studying their elimination. Three processes are 

 employed in the search for lead and copper, they really differ from 

 each other only in the agents employed for the carbonization of the 

 animal matter. These agents are nitric acid, nitric acid mixed with one- 

 fifth of chlorate of potassa, and sulphuric acid. From my experiments I 

 conclude that the carbonisation by nitric acid is superior to the others ; 

 that the mixture of nitric acid and chlorate of potassa does not give good 

 results, and, finally, that carbonisation by sulphuric acid is far inferior 

 to the others. When we seek for mercury, the bestof known pro- 

 cesses consist in carbonising the organic matter with sulphuric acid. 

 M. Lanaux proposes the destruction of this matter by a current of chlo- 

 rine. Comparative experiments have shown me that this last process 

 is more sensible than the former. Comptes Rendus. 



ON THE ACTION OF OZONE ON MIASMATA. BY M. SCHONBEIN. 



M. SCHONBEIN'S additional researches have still further developed 

 the analogy of this substance to chlorine, and leave no doubt of the 

 injurious effects it may exert on the respiratory organs when in excess. 

 Mice soon perish in an atmosphere containing 1-6,000. The quantity 

 which prevails in the atmosphere is very variable, being proportionate 

 to the amount of electricity, and therefore at its maximum in winter, 

 and its minimum in summer. It is, however, highly probable that, 

 when existing only in minute quantities, it exerts a purifying effect 

 on the atmosphere by destroying various deleterious miasmata. There 

 are a great number of inorganic gaseous bodies, which when diffused 

 in scarcely appreciable quantities, yet render the air irrespirable. An 

 incessant source of miasmata exists in the variety of gaseous com- 

 pounds which are incessantly liberated by the decomposition of the 

 innumerable masses of organic beings which' perish on the surface of 

 our globe. Although the composition of most of these is unknown, it 

 is supposed that their accumulation would render the air unfit for 

 respiration. Nature has, however, provided the means of destroying 

 such deleterious compounds as fast as they are generated, for M. 

 Schonbein regards ozone, which is so constantly generated under 



