SCIEXCE-GOSSIP. 



incomparable richness, can be prepared from indigo, 

 but is now got directly from coal tar. Of the aniline 

 dyes so obtained may be mentioned rosaniline, or 

 aniline red, which gives the beautiful magenta, 

 and which was discovered owing to the deep 

 red colour produced by the action of nitric acid 

 on aniline. 



The chemist has succeeded in preparing many 

 of the odoriferous products of plants, such as 

 bitter almond oil, used for scenting soaps, and a 

 flavouring agent in cooker}- ; the oil of mustard, 

 already mentioned, obtained from the mustard 

 plant, and occurring also in the root of the common 

 mignonette ; and the sweet smelling principle of 

 the meadow sweet. Salicylic acid, formerly 

 obtained from the winter-green plant, is now 

 artificially produced on a large scale. It is largely 

 used as an antiseptic, and is useful for the preserva- 

 tion of articles of food, being free from taste and 

 smell. The artificially prepared vanilla, the 

 familiar flavouring agent in chocolate and con- 

 fectionery, will probably replace the natural 

 substance, which is obtained from the pods of 

 orchids. Some of the alkaloids, the valuable com- 

 pounds used in medicine, have also been artificially 

 prepared — atropine, occurring as a constituent of 

 belladonna, which exercises a characteristic effect 

 on the pupil of the eye ; and coniine, the active 

 principle of hemlock. The constitution of the 

 alkaloid nicotine, the poisonous oil of stupe- 

 fying odour occurring in tobacco, is also very well 

 understood, and the attempt to prepare it artificially 

 will probably be successful. 



Lastly, two varieties of the sugars, that interesting 

 class of bodies so useful to mankind, and to the 

 production of which from plant life so much land 

 and labour are devoted, have recently been artifici- 

 ally obtained. These are the glucose, or grape 

 sugar, contained in most sweet fruits, and forming 

 the solid and crystallizable part of honey : and the 

 sweeter laevulose contained in grapes, cherries, figs, 

 and gooseberries. There is now used, to a certain 

 extent, in lieu of the natural sugar the substance 

 saccharine, manufactured from a derivative of 

 coal-tar. 



It is impossible to foresee how far the art of the 

 chemist may be successful in the artifical formation 

 of the innumerable organic substances occurring in 

 nature, and to what extent our foods even may in 

 time be provided by chemical processes in the 

 laboratory. In view of the increasing populations 

 of the globe, and the struggle for existence, the 

 importance to mankind of such investigations 

 cannot be over-estimated, while apart from their 

 value as a means of affording easier conditions of 

 existence, it is interesting to find the marvellous 

 processes of nature so successfully imitated. 



45, Comity Bank Avenue, Edinburgh ; 

 January 22nd, 1895. 



BERLIN NATURAL HISTORY 

 MUSEUM. 



A/TUSEUM work being a branch of natural 

 history that demands increasing attention, 

 as its importance is more fully realized, it may 

 interest the readers of Science-Gossip to see the 

 following notes on the " Museum fur Naturkunde," 

 m Berlin. Though not nearly so large or complete 

 as the Natural History Department at South 

 Kensington — the whole collection open to the 

 public consisting only of ten galleries — there are 

 many particularly important specimens and series. 

 Perhaps the most remarkable of all the exhibits 

 is the famous Archaopteryx, that lizard-like fossil 

 bird which has excited and still is exciting so 

 much discussion among palaeontologists. -Beside it 

 is a cast of the London specimen, so that the two 

 may easily be compared and studied. In the same 

 room is a single feather of another species of 

 Archceoptcryx (A. Uthographka). Although there -is 

 nothing to correspond to the large central 

 introductory hall at South Kensington, with its 

 splendid educational examples, one cannot help being 

 struck with the number and excellence of the educa- 

 tional models distributed throughout the rooms. 

 For instance, there is a series of twenty-two models 

 illustrating the development of the frog's ovum, 

 another series illustrating that of the trout's ovum. 

 In all departments we find simple and artistic 

 models of the circulation, muscular system, 

 digestive apparatus and others, with all the parts 

 clearly named. Among other interesting models 

 are those of the labyrinths of ears, of mammalian 

 brains, a series showing the different positions 

 used in the flight of a seagull, a realistic oyster 

 bed, a coral reef, and a series showing the different 

 forms of Echinoderm larvae. The birds are not 

 arranged in the artistic manner as at South 

 Kensington. There are two collections : the first, 

 native ; the second, a systematic collection of birds ; 

 and the same system is used for the mammals. In 

 both these rooms there are a great many skeletons 

 with the names plainly marked, so that each bone 

 is clearly recognizable. The insect room has a 

 particularly interesting and beautifully got up 

 series of the various plant-lice, aphides, gall-flies, 

 etc., which injure plants, showing the harm they 

 effect. The Lepidoptera are all kept in glass cases 

 and rot protected from the light at all, but they do 

 not seem to have suffered in consequence, their 

 colours retaining their brightness well ; the same 

 may be said of the dragon-flies. The Echino- 

 dermata and Coelenterata are very well represented. 

 At present there are no guides published to the 

 museum, which is a great loss. The botanical 

 collections are not kept in the same building, but 

 in a museum in the Botanical Gardens. 



Catherine A. Winckworth. 

 11, Old Stcine, Brighton May 22nd, 1895. 



