Habitual drinkers of aërated beverages were some time ago startled by the report that the original source of the water used in the manufacture did not much trouble the attention of the vendors, and that micro organisms in fabulous numbers might find their way to the consumers of these apparently innocent fluids. According to Dr T. Leone’s researches, aërated waters are peculiarly safe from such contamination. Taking a typically pure potable water, he tried how many micro organisms could be developed in it in a given time. In five days the water contained immense numbers of organisms. But when charged with carbonic dioxide, as all aërated waters must be to give them their effervescent quality, the number of living creatures was at once diminished. Water so charged contained at the end of fifteen days only a mere trifle of the original organisms. Dr Leone therefore concludes that the longer aërated waters are kept, the less chance is there of bacterial contamination. The greatest living authority on bacteria, M. Pasteur, has by recent experiments proved that water containing only two per cent. of concentrated sulphuric acid possesses the property of destroying these organisms. He recommends that this acidulated water should be used as a disinfectant for floors of stables, mangers, courtyards, cattle-sheds, &c. The compound has certainly the merit of extreme cheapness, for about twelve gallons could be prepared at a cost of twopence. We may mention that M. Pasteur’s inoculations for hydrophobia have met with unlooked-for success. He recently told the Paris Academy of Sciences that out of three hundred and twenty-five cases of inoculation for this terrible disease, only one had proved a failure, and that one he attributed to delay. It is suggested that an international hospital should be established for the reception of patients from every country. The all-seeing microscope has very often played an important part as an accusing witness, more especially in the identification of blood-stains. Recently in Illinois the same detective agent was instrumental in hanging a murderer; but the method of conviction was novel. Here is the case: A. had been found murdered while sleeping on a pile of sawdust in a certain icehouse, which we will call No. 1. B. was suspected of the crime because particles of sawdust were found on his clothing and on his boots. He accounted for this by pleading that he had been sleeping in another icehouse (No. 2) which was far away; and declared that he had not been near the No. 1 house. It was proved that icehouse No. 1 contained _pine_ sawdust, and house No. 2 hardwood sawdust only. The microscope showed that the clothes and boots had attached to them particles of the former only. The man was convicted and executed.