CHEMISTRY. 



211 



perfectly understood ; and when oxygen is com- 

 pletely excluded, they remain unchanged. It 

 then remained a problem, important in connec- 

 tion with the vital processes of the animal or- 

 ganism, to determine what becomes of gaseous 

 hydrocarbons escaping into the air during putre- 

 fa'ctive decay, and of other particles set free in 

 air, such as "the odorous, &c. ; the probability 

 being that these would be acted on in like man- 

 ner. This also Karsten believes he has now- 

 proved by experiment (" Philos. Mag.," 1862). 

 Through a carefully cleaned apparatus of small 

 tubes and bulbs, he passed about 30 gallons of 

 moderately heated air, at the slow rate of about 

 9 pints in 12 hours. The air before entering 

 was passed through caustic potash, with precau- 

 tions to secure the removal from it of all con- 

 tained carbonic acid. Just before its escape from 

 the apparatus, it passed again through pure 

 caustic potash or lime water. If now, before ad- 

 mission to the first solution of potash the air was 

 heated to redness, so as at once to burn up all 

 the organic matter in it, then in no case did the 

 second potash solution or lime water give indi- 

 cations, by forming of carbonate of potash in 

 the one case, or by turbidity in the other, of 

 presence of carbonic acid ; but if the admitted 

 air were not thus burned, during the slow p . 

 of the current the lime water soon became tur- 

 bid, or the potash solution gained in weight, 

 and yielded some carbonate of potash. The 

 carbonic acid thus appearing must have been 

 generated by slow combustion of gases or par- 

 ticles containing carbon, in the air while mov- 

 ing through the tubes. [Query : Did the con- 

 densing power of surfaces, as in case of plati- 

 num sponge or a clean platinum slip, have any 

 influence in producing the result given t] 



III. ALLOTROPIC STATES. Oxygen. One of 

 the most singular, and now somewhat familiar 

 principles determined by modern chemistry, is 

 that of allotropism, or the existence of the 

 same element in several conditions, in which 

 both its physical qualities and chemical be- 

 havior are almost or entirely different. One 

 of the most familiar instances is afforded 

 by the element carbon, in its two extremely 

 unlike states of diamond and coke or char- 

 coal. So, phosphorus exists as the ordinary 

 yellow solid, and in transparent crystals, both 

 highly poisonous and inflammable in air, and 

 again, as red or amorphous phosphorus, in 

 which state its inflammability and poisonous 

 character are in comparison well nigh lost, and 

 its properties in other respects are greatly 

 changed. Among the most interesting in- 

 stances of the sort, however, is that of allo- 

 tropic oxygen or ozone, discovered some years 

 since by Prof. C. F. Schonbein. More recent- 

 ly, this chemist has endeavored to show that 

 beside the division of ordinary oxygen and 

 ozone, a second must be made, the ozone itself 

 obtained from different sources and under 

 unlike conditions behaving differently toward 

 other bodies, in such a way as to suggest that 

 it has two opposite or polar conditions, which 



he proposes for distinction's sake, to mark as 

 and -f ozone, or to name ozone and ant- 

 ozone. In a communication during the year 

 1862, he states that he succeeded in isolating 

 ozone from an ozonide (an oxide containing the 

 allotropic oxygen) ; and has found tests, not 

 named, for completely distinguishing the two 

 ozones. The following is his latest method of 

 producing ozone by purely chemical means : 

 Dissolve pure manganate of potash in pure 

 sulphuric acid, and introduce into the green so- 

 lution pure peroxide of barium ; common oxy- 

 gen and ozone will both be set free ; the latter 

 being detected by the nose, and by other tests. 

 With such ozone, Schonbein has oxidized silver 

 at 20C.= 4: F. ; and by inhaling it, secured 

 a capital catarrh. 



Sir B. C. Brodie, in a paper before the Royal 

 Society, Xov. 21, 1862, claims to have antici- 

 pated in 1850 Schonbein's view that oxygen 

 may exist in opposite polar conditions ; while 

 he presents experiments tending as he thinks 

 to show that the differences in behavior of 

 different classes of peroxides do not warrant 

 the distinction of the contained oxygen into + 

 and , the differences appearing not to be fun- 

 damental and characteristic. He further lays 

 down a somewhat new principle, to the effect 

 that, in no case are the properties of chemical 

 substances that may enter into composition 

 constant for each substance, as their atomic 

 weights are known to be ; but that the proper- 

 ties are variable, depending in degree on the 

 physical conditions in which the particles may 

 be placed, and the nature of the other sub- 

 stances with which they become associated. 



Prof. T. S. Hunt's communication (" Amer. 

 Jour, of Science," March, 1861) helps to show 

 the intricacy and unsettled state of this subject. 

 The formation of a nitrite in moist air ozonized 

 by the electric spark (Cavendish's old experi- 

 ment), or by phosphorus, being shown by 

 Rivier and de Fellenberg, they concluded that 

 Schonbein's ozone was really nitrous acid 

 (XO 3 ). Marignac and Andrews, however, sub- 

 sequently established that ozone is modified 

 oxygen ; and Houzeau proved its identity with 

 the so-called nascent oxygen, as evolved along 

 with the common form when peroxide of bari- 

 um is decomposed by sulphuric acid. Prof. 

 Hunt had proved that nitrous acid is generated 

 when a current of air is caused to pass through 

 permanganate of potash undergoing solution in 

 sulphuric acid. He had suggested in 1848 that 

 gaseous nitrogen is the anhydride amide, or 

 nitryl of nitrous acid, its proper formula being 

 XX. and which, in contact with water, could 

 generate at once both nitrous acid and ammo- 

 nia (XO 3 and XH 3 ) : and as the ammonia, while 

 forming, is readily attacked by nascent oxygen 

 when present, giving both nitrate and nitrite 

 of ammonia, it follows that, ozone being 

 brought in contact with moist air, both the ni- 

 trogen atoms of the nitryl may appear in the 

 oxidized state (giving XH 4 O . XO 3 , or nitrite 

 of ammonia). This view will be seen to connect 



