98 



CHEMISTRY. 



action which had gone on, and the amount 

 of sulphur was quite small. Several notices 

 of a similar transformation of cast-iron into 

 graphite occur in the annals of chemistry, the 

 oldest one dating as far back as 1740. Wrought 

 or malleable iron does not appear to be subject 

 to it. The plumbaginous masses thus formed 

 frequently but not invariably become red hot 

 and spontaneously inflammable on exposure to 

 the air. The transformation is attributable to 

 the local galvanic action set up between the 

 diffused scales of graphite, films of slag, or 

 other foreign matter contained in the iron. 

 The coating of plumbago and rust is negative 

 to the metal, and hence if left on assists in 

 further corrosion ; but the rate of corrosion, 

 according to the observations of Mr. Robert 

 Mallet, appears as a decreasing one when the 

 coating first formed is removed prior to a sec- 

 ond immersion. When cast-iron is exposed to 

 the combined action of fresh water and sea- 

 water, the action is said to be much more 

 rapid, for the heavier sea-water below, and 

 the lighter fresh water above, with the iron, 

 form a voltaic pile having two liquids and one 

 solid. 



A NEW MINERAL, BEEGERITE. Mr. George 

 A. Konig has described and analyzed a new 

 mineral from the Baltic lode of the Geneva 

 Mining Company, Park County, Colorado, to 

 which he has given the name of beegerite. 

 The specimen on which the investigation was 

 made was composed of quartz, about one half, 

 and the new mineral in the two conditions of 

 a light gray mass, and of crystals showing 

 a darker gray color but exhibiting a very 

 strong metallic luster, which were chemically 

 identical with the gray mass. Beegerite forms 

 minute crystals of orthorhombic habit ; has a 

 specific gravity of 7'273 ; acts before the blow- 

 pipe like a mixture of galenite and bismutbite, 

 with a small quantity of copper, and decrepi- 

 tates ; and is dissolved by concentrated hydro- 

 chloric acid, slowly in the cold, but rapidly in 

 the heated acid. The analyses gave it a com- 

 position represented by the formula, Pb Bi a 

 S = 6 PbS + BUSs, with some copper. The 

 compound exhibits properties nearly coinciding 

 with those of galeuite, and is qualitatively re- 

 lated with the two species, cosalite and schir- 

 merite. 



THE ALKALOID OF PITURIE. Professor Liver- 

 sidge, of Sydney, New South Wales, has ex- 

 tracted the alkaloid principle of piturie, a 

 vegetable substance obtained from a species of 

 Duboisia, of the order Solanacea, which is 

 chewed by the Australian natives, and exerts 

 an action similar to that of tobacco. Baron 

 von Mueller and M. A. Ladenburg had pre- 

 viously experimented with the alkaloid, but 

 their accounts of it do not agree. As prepared 

 by Professor Liversidge, by distillation of the 

 plant with caustic soda, solution in ether, and 

 removal of the ether by distillation, the alka- 

 loid, piturine, is at first clear and colorless, but 

 becomes yellow and finally brown with access 



of air, especially when exposed to sunlight. If 

 air is excluded it will remain unchanged for a 

 long time. It is soluble in all proportions in 

 water, alcohol, and ether, yielding colorless 

 solutions, and produces a greasy stain on paper, 

 which disappears after a time. It is a little 

 heavier than water, is volatile at ordinary tem- 

 peratures, giving a vapor which forms a dense 

 fog with hydrochloric acid, irritates the mu- 

 cous membranes very much, and induces vio- 

 lent headaches in those working with it. Its 

 taste is acid and pungent, and very persistent ; 

 its smell when fresh is very like that of nico- 

 tine, but after it has become darkened is more 

 like that of pyridine. It neutralizes acids com- 

 pletely. Its composition is represented by the 

 formula CoHgNu. 



CULTIVATION OF NITRIC FERMENTS. Mr. R. 

 Warington has communicated some prelimi- 

 nary results of a course of experiments he has 

 been making on the conditions in fermentation 

 which respectively determine the formation of 

 nitric and nitrous acid. When a small quan- 

 tity of fresh soil is employed to seed solutions 

 of chloride of ammonium supplied with nutri- 

 tive ingredients, a pure, or nearly pure, nitric 

 fermentation is obtained if the solution is suf- 

 ficiently shallow and dilute, and the tempera- 

 ture low. Under such circumstances only a 

 trace of nitrous acid is formed, and this changes 

 into nitric acid before the conclusion of the 

 action. If the solutions employed are much 

 more concentrated, or the temperature is con- 

 siderably raised, large quantities of nitrous acid 

 are produced. In all cases in which soil has 

 been used as seed, the nitrous acid exists only 

 temporarily in the solution, the final product of 

 the fermentation being always nitric acid. Soil 

 added to a solution of nitrite of potassium, sup- 

 plied with nutritive ingredients, readily converts 

 the nitrite into nitrate. When solutions which 

 have been seeded with soil and have undergone 

 the nitric fermentation are themselves employed 

 as seed for new solutions of ammonia, the final 

 result as before is nitric acid, provided the so- 

 lution used as seed is only a few months old. 

 With older solutions the result of the fermen- 

 tation is apparently only nitrous acid, which 

 does not further change into nitric acid, except 

 when, as sometimes occurs, a white organism, 

 a bacterium, after a considerable time, appears 

 on the surface of the liquid, and spreads, under 

 favorable circumstances, to cover it. When a 

 solution which has undergone the nitrous fer- 

 mentation is used as seed, it again produces a 

 purely nitrous fermentation. These results ac- 

 cord with the fact noticed by Pasteur, that the 

 energy of infectious organisms may be reduced 

 by cultivation. The nitrifying ferment appears, 

 then, to exist in the three conditions of the 

 nitric ferment of the soil, producing nitrates ; 

 the altered ferment producing nitrites ; and the 

 surface organism, which changes nitrites into 

 nitrates. 



RELATIONS OF BACTERIA AND VARIOUS GASES. 

 Mr. F. Hatton has made some experiments to 



