104 



CHEMISTRY. 



mixed acids, it always has the doughy form. 

 That obtained by the use of nitric and sul- 

 phuric acid was crystalline from the first. 

 When precipitated by water from its solution 

 in alcohol and ether, it is doughy and almost 

 liquid, and remains so for a long time, if there 

 is any considerable quantity of it. The best 

 mode of preserving it appears to be under 

 water. By standing thus it gradually hardens, 

 and passes sometimes to a somewhat hard 

 amorphous mass, and sometimes to a granular 

 crystalline state. It appears to be wholly in- 

 soluble in water. A few minute grains of the 

 crystalline form diffused through fifteen or 

 twenty ounces of water, and did not dissolve 

 after many hours' standing. In a mixture of 

 alcohol and ether it dissolves as easily as 

 sugar in water, and in such quantity as to 

 make the liquid syrupy. Its detonating prop- 

 erties are but slight. If it be well dried and 

 a match be applied, it deflagrates with a feeble 

 flash. It has been stated by Dr. Y. Monck- 

 hover that, when dissolved in alcohol and kept 

 some time in a warm place, it undergoes de- 

 composition, as shown by the fact that the 

 solution then gives an abundant precipitate 

 with nitrate of silver, which at first it did not 

 do. An experiment made in this direction 

 did not give the result thus indicated. A solu- 

 tion of nitroglucose in alcohol, containing 

 about forty grains to the ounce, was placed in a 

 stoppered phial and was kept in the sand-bath 

 at a temperature of about blood-heat for nearly 

 a month. But neither it nor a fresh solution 

 gave a precipitate with alcoholic solution of 

 nitrate of silver. 



Ozone and Antozone. An experiment of M. 

 Schonbein's, illustrating the simultaneous for- 

 mation of ozone and antozone, is said to be the 

 following : Into a flask of five hundred c. c. 

 capacity, and three or four centimetres in di- 

 ameter across the neck, a little ether is poured, 

 just enough to cover the bottom, and a spiral of 

 red-hot platinum is plunged into th e vapors. It is 

 necessary to avoid heating the flask too strong- 

 ly. The platinum glows until all the ether has 

 been destroyed. The experiment is repeated 

 two or three times, and now the question is, to 

 demonstrate that both ozone and antozone are 

 formed in this slow oxidation of the ether. 

 The first is, of course, easily shown to be pres- 

 ent by means of the iodide of potassium and 

 starch-paper. To show the presence of anto- 

 zone, the flask is rinsed with a small quantity 

 of ether, which will then be sufficiently charged 

 with peroxide of hydrogen to give clearly the 

 perchromic acid reaction. Some solution of 

 bichromate of potash is placed in a test-tube, 

 and a drop of sulphuric acid added, the ether 

 with which the flask has been rinsed is then 

 poured in, when the ethereal layer becomes 

 colored a beautiful violet blue. The conclusion 

 to be arrived at from this experiment is, that, 

 during the formation of ozone, antozone is also 

 formed this, in the presence of water, being 

 converted into peroxide of hydrogen. 



During the autumn of 1867, when the chol- 

 era was felt severely in Turin, Father Denza 

 studied the meteorological condition of the at- 

 mosphere; he studied especially the connec- 

 tion between the prevalence of the disease and 

 the absence of ozone. His observations were 

 made at Moncalieri, rather more than half a 

 mile from the town ; the electricity was meas- 

 ured as well as the ozone. During the days in 

 August and September, when the cholera was 

 at about its height, the amount of ozone pres- 

 ent was variable, but considerable perhaps 

 about the average. The electricity, however, 

 during these days almost entirely disappeared ; 

 it is an interesting observation. 



Professor Frankland made this reference to 

 the ozone question in his address to the Chem- 

 ical Section of the British Association, in Au- 

 gust, 1868: 



Chemists had long regarded with regret the labor 

 expended by meteorologists on observations made 

 with the intention of estimating ozone in the atmos- 

 phere, in the absence of any conclusive evidence of 

 the existence of this substance in the air. It is, 

 therefore, highly satisfactory that Andrews, to whom 

 we were already so much indebted for our knowledge 

 of the properties of ozone, has at length proved that 

 the reaction exhibited by ozone test-papers at a dis- 

 tance from towns is in reality due to ozone. Thus 

 the numerous observations, extending over so many 

 years, now attain a value which they did not before 

 possess. 



Microscopic Crystallography. Mr. H. S. 

 "Waddington has read a paper before the Brit- 

 ish Pharmaceutical Society, on this subject. He 

 says that the formation of perfect crystals de- 

 pends upon the rapidity with which they are 

 deposited. He has obtained better results, by 

 allowing the crystals to deposit from a hot and 

 concentrated solution, than by placing a few 

 drops of a cold saturated solution on a clean 

 slide and allowing it to evaporate spontaneous- 

 ly. "When crystals are quite soluble in water, 

 his mode of procedure is as follows : "A solu- 

 tion is made in hot distilled water, the liquid 

 filtered, and a few drops poured on a clean 

 slide, just before the crystals begin to form in 

 the solution itself, and immediately poured off; 

 sufficient will remain behind for the produc- 

 tion of crystals, which will form at once. 

 "When of a sufficient size, the remaining liquor, 

 if any, should be drained from them and the 

 slide allowed to dry. The result will generally 

 be a slide, evenly covered with crystals, having 

 well-defined edges, and but few of which are 

 agglomerated. This process answers well for 

 alum, chlorate of potassium, nitrates of ba- 

 rium and strontium, potassio-tartrate of anti- 

 mony, sulphate of copper, sulphate, acid tar- 

 trate, binoxalate, and quadroxalate of potassium, 

 the strength being regulated by experience. 

 If crystals are not very soluble in cold water, 

 they may be allowed to separate in the bulk of 

 the solution itself as it cools ; then remove a 

 small quantity of liquid and crystals to a slide, 

 by means of a glass tube. The slide must be 

 kept moving, to prevent the aggregation of the 



