2IO 



NA TURE 



[June 30, iii92 



The facility with which enlargements can now be produced, 

 and the introduction of good commercial bromide paper, to say 

 nothing of the artistic effects of the results, haVe all tended to 

 increase the popularity of the practice of enlarging. When 

 an amateur was formerly in need of moderate-sized pictures, 

 he was compelled more or less to use a large camera, but now 

 the inclination is to employ small cameras and therefore small 

 plates, and to subsequently adopt the enlarging process to give 

 him the required size picture. A very useful and handy little 

 book treating of this process, written by Mr, John A. Hodges, 

 has lately been issued by Messrs. Iliffe and Son, and contains 

 much practical information for working either by artificial light 

 or daylight. Methods of constructing cameras suitable for this 

 work, lanterns, and various accessories, are all very well described 

 and illustrated, and if carefully followed out will render many an 

 amateur independent of the instrument-maker. In the section 

 relating to the chemical manipulations there are also some use- 

 ful hints which will save a beginner much annoyance and help 

 him to produce satisfactory results. 



Oberlin College, Ohio, is issuing a series of Bulletins 

 giving the results of special work done in its museum and 

 laboratories. Two have now been published, the first being a pre- 

 liminary list of the flowering and fern plants of Lorain County. 

 The second, which we have just received, contains a descrip- 

 tive list of the fishes of Lorain Connty, and has been prepared 

 by Mr. L. M. McCormick. 



According to the Pioneer Mail of June 8, the residents of 

 Howrah have been finding lately that jackals are animals of 

 anything but an attractive temper. In some cases they have 

 come right up to the bungalows in search of prey. A little 

 girl, aged about five years, was playing in a verandah, when a 

 jackal suddenly rushed on her, and was dragging her away, when 

 she was rescued. She was severely bitten. Three natives, 

 while walking along Kooroot Road, were attacked by a jackal, 

 which was only driven off after a stubborn fight ; and a tale 

 is told of two women, while standing near a tank, being at- 

 tacked and bitten. So serious has the state of matters become, 

 that the public propose to submit a memorial to the district 

 magistrate praying for the adoption of measures for the destruc- 

 tion of these pests. 



Referring to Malta's spring visitors, the Mediterranean 

 Naturalist for June says that during the preceding month the 

 valleys and gorges were alive with orioles, warblers, rollers, 

 and bee-eaters. In the rich crimson clover enormous numbers 

 of quails found shelter during their sojourn en route for the 

 Continent, while the branches and foliage of the carob, the 

 prickly pear, and the orange trees were thronged with harriers 

 and larks. 



Mr. F. Turner contributes to the April number of the 

 Agrictdtural Gazette of New South Wales a paper on the carob 

 bean tree as one of the commercial plants suitable for cultivation 

 in New South Wales. The Agricultural Department distributed 

 a quantity of seed last year, and some healthy young plants 

 raised from this seed are now growing in several parts of the 

 colony. Mr, Turner expects that when the tree becomes better 

 known to cultivators it will be extensively grown to provide food 

 for stock, more especially during adverse seasons. The carob can 

 not only be trained into a very ornamental shade tree, but may 

 be planted as a wind-break to more tender vegetation. He 

 advises all who cultivate it to keep bees, if only a single hive. 

 It is astonishing, he says, how many flowers these industrious 

 insects will visit in the course of a day, and be the agency 

 whereby they are fertilized. 



Some time ago a sugar school was established in connection 

 with the State University, Lincoln, Nebraska, and if we may 

 NO. I 183, VOL. 46] 



judge from the first formal report, lately submitted by Prof* 

 Lloyd, it is likely to do much excellent work. The school 

 opened on January 5 with twenty-five students. These students 

 were mostly members of other classes in the chemical department 

 of the University ; the only preparation required for entrance 

 being a clear conception of the principles of elementary chemistry, 

 such as may be obtained in some of the high schools of Neb- 

 raska. The course consisted of two lectures a week, given by Mr. 

 Lyon, with five hours of laboratory work. The lectures em- 

 braced the following subjects : (i) chemistry of the sugars ; (2) 

 technology of beet-sugar manufacture ; (3) culture of the sugar 

 beet. During the latter part of the winter term, Prof. DeWitt 

 B. Brace gave the class four lectures on the theory of light, deal- 

 ing with (i) the wave theory of light ; (2) polarization of light ; 

 (3) rotation of the plane of polarization ; (4) application of these 

 principles to the polariscope and to the different forms of 

 saccharimeters. It is hoped that in the coming year the work 

 may be greatly extended. 



A " Dictionnaire de Chimie industrielle " is being issued in 

 parts, under the direction of A, M. Villon, by the " Librairie 

 Tignol." It gives an account of the applications of chemistry 

 to metallurgy, agriculture, pharmacy, pyrotechnics, and the 

 various arts and handicrafts. 



Messrs. Longmans, Green, and Co. have issued a third 

 edition, revised and enlarged, of Prof. E. A. Schafer's 

 " Essentials of Histology." The intention of the author is to 

 supply students with directions for the microscopical examination 

 of the tissues. 



A WORK on the " Migration of Birds," by Charles Dixon, 

 will shortly be published by Messrs. Chapman and Hall. 



A paper upon the oxidation of nitrogen by means of electric 

 sparks is contributed, by Dr. V. Lepel, to the current number 

 of the Annalen der Physik und Chemie. It is well known that 

 small quantities of nitric and nitrous acids and their ammonium 

 salts are produced during the passage of high tension electrical 

 discharges through moist air. Dr. V. Lepel's experiments have 

 been conducted with the view of obtaining more precise infor- 

 mation concerning the nature of the chemical reactions which 

 occur, and the experimental conditions most favourable for in- 

 creasing the amount of combination. The first action of the 

 spark discharge appears to be the production of nitric oxide, 

 which is immediately converted by the oxygen present into 

 nitrogen peroxide. The latter then reacts with the aqueous 

 vapour present, forming nitric acid and liberating nitric oxide in 

 accordance with the well-known equation 3NO2 -t- HjO — 

 2HNO3 -{- NO. It has been found, however, that the con- 

 tinued passage of sparks through the same quantity of moist air 

 does not result, as might at first sight be expected, in the con- 

 version of more and more of the atmospheric gases into oxidized 

 products. For the passage of sparks through the gaseous oxides of 

 nitrogen first formed results in their decomposition again into their 

 elementary constituents. If, for instance, spark discharges are 

 passing at the rate of one per second, the whole of the nitrogen 

 peroxide molecules have not time to react with the water mole- 

 cules to form nitric acid, before the passage of the next spark, 

 and hence some of them suffer decomposition ; indeed, it is 

 probable that a number of the nitric oxide molecules first formed 

 have not even time to combine with oxygen to form the peroxide 

 before the passage of the next discharge, which brings about 

 their dissociation. Hence it is that, in a closed space, a limit is 

 soon reached beyond which there is no further increase in the 

 amount of nitric acid. For this reason the yield of nitric acid 

 has hitherto been very small. Dr. V. Lepel has made experi- 

 ments, therefore, with a slowly moving atmosphere, and under 

 different conditions of pressure, and with various types of spark 



