276 ANNUAL OF SCIENTIFIC DISCOVEKY. 



provided a sufficient quantity of these solutions be used ; it has always the 

 same peculiar odor ; it bleaches without producing previously an acid reac- 

 tion ; it oxydizes in all cases the same bodies, etc. From the whole investi- 

 gation the author draws the conclusion "that ozone from whatever source de- 

 rived, is one and the same substance, and is not a compound body, but oxygen 

 in an altered, or allo tropic condition." Proc. Royal Society. 



Influence of Ozone. For some time pasl continuous observations have been 

 made in Europe on ozone. The general result of many scattered observers 

 seems to show that there really exists an intimate connection between the 

 quantity of ozone in the air and certain epidemic diseases, such as cholera, 

 grippe, intermittent fever, etc. It is claimed to have been established that the 

 appearance of the grippe coincides with the presence in the air of an excess 

 of ozone ; while on the contrary the invasion of cholera is accompanied by an 

 almost complete absence of ozone in the air ; this is at least true for Berne, in 

 Switzerland, and Strasburg and Nancy, in France. It will be remembered that 

 this view of the connection of ozone with cholera was taken by some of the 

 medical journals in the United States in 1849, at the time of the cholera in- 

 vasion. 



The following is a new mode of preparing ozone, or a similar body, which 

 is capable of oxydizing silver, decomposing iodide of potassium, of forming 

 ammonia, of disengaging chlorine from hydrochloric acid, and of forming water 

 with hydrogen. It consists in treating peroxyd of barium with monohydrated 

 sulphuric acid at a temperature below 70 Centigrade. The oxygen disengaged 

 in this process possesses the properties named above, and it has the charac- 

 teristic odor which is known as the lobster odor. 



ON THE PREPARATION OF CALOMEL IN THE HUMID WAT. 



It has long been known that protochlorid of mercury is precipitated from 

 the solution of the perchlorid, by sulphurous acid. This behavior appears 

 to be available in the practical preparation of calomel. It is obtained as a 

 very delicate powder in this manner, and of a dazzling white color, which 

 glistens in the sunlight. The difficult process of sublimation, and the tedious 

 preparation would be thus avoided, and its preparation in the laboratory 

 would be a very easy matter. It would be obtained immediately in the 

 finely-divided state in which the pulverulent sublimed calomel is procured, 

 without any necessity for an operation of so much danger as the preparation 

 of calomel by sublimation, which, moreover, can only be performed on a 

 large scale. As the calomel formed by sulphurous acid is crystalline, and 

 therefore in the same condition as the sublimed, there can also be no doubt 

 that it will not differ from this in its medicinal efficiency. For its preparation 

 it is only necessary to dissolve commercial perchlorid of mercury in water 

 heated to about 122 Fahrenheit, until this is saturated, and afterward to pass 

 sulphurous acid gas into the hot solution. The gas is evolved by heating 

 coarse charcoal powder with concentrated sulphuric acid. The separation of 

 the calomel commences immediately. When the solution is saturated with 

 gas, it is digested for a time, then left to get cool, and filtered from the 



