622 



NATURE 



[October 26, 189c 



It is usual in cases of thrush to recommend the use of 

 alkaline substances in order to counteract the acidity of the 

 mouth, which is generally supposed to favour the growth of the 

 thrush fungus. Some recent researches of Marantonio (" Con- 

 tributo alia biologia del fungo del Mughetto " Istituto d'Igiene 

 di Roma, vol. xii. 1893, p. 199) show, however, that this 

 fungus grows abundantly in strongly alkaline as well as in acid 

 media. Experiments were made to ascertain what substances 

 exerted a bactericidal action on this organism, special attention 

 being given to those usually prescribed in the treatment of 

 thrush. It was found that many of these were quite ineffective, 

 on the other hand salicylic acid, amongst others, was highly 

 efficacious ; these laboratory experiments were, moreover, con- 

 firmed in actual practice, for extremely encouraging results were 

 obtained when this substance was tried in some cases |of thrush 

 in children in one of the hospitals in Rome. In some hospitals 

 it appears that thrush is endemic, and Marantonio was able to 

 isolate out the organism of this disease from the dust in the 

 interstices of the flooring of a children's ward ; considering that 

 the fungus can successfully resist the effects of desiccation over 

 four and a half months, this fact is not surprising. The 

 behaviour of this organism when exposed to sunshine was also 

 investigated. Portions of vigorous agar-cultures were spread in 

 thin layers on pieces of white cardboard, which were placed in 

 glass boxes, some being preserved in the dark, whilst others 

 were insolated for various lengths of time. It was found that 

 thirteen hours' exposure to direct sunshine retarded the develop- 

 ment of the fungus, whilst when prolonged for seventeen hours 

 it was completely destroyed. The great mortality which prevails 

 amongst children suffering from thrush should render these 

 elaborate and carefully-conducted experiments of especial 

 interest and importance. 



Carbide of boron has been isolated by Dr. Miihlhiiaser, of 

 the University of Chicago, and is described by him in the 

 current publication of the Zeitschrift fiir Anorganische Chemie. It 

 proves to be an extremely stable substance, being capable of 

 successfully resisting the action of almost all the usual solvents 

 and reagents. Its composition has been ascertained by taking 

 advantage of the fact that chromate of lead is capable of 

 oxidising it at the usual temperature of a combustion furnace. 

 The analytical data indicate the simple empirical formula BC, 

 but its constitution is assumed to correspond to double that 



C = B 

 formula, namely BjC™ or | . Boron carbide was prepared 



CEEB 

 by heating boric anhydride with the hard variety of carbon 

 employed for making the terminals of electric arc lamps. The 

 reaction proceeds in accordance with the equation : B2O3 4- 5C 

 = B„C» -f 3CO. Five parts of borax were dissolved in twenty 

 parts of water, one part of sulphuric acid was added, and the 

 solution allowed to cool. The crystals of boric acid which 

 were formed during the cooling were separated by filtration, 

 washed with water, dried, fused, and finally heated to low red- 

 ness, by which they were dehydrated, and boric anhydride 

 produced. The powdered boric anhydride was then mixed 

 with the powdered electrode carbon, in the proportion of five 

 parts of the former to eight parts of the latter, and the mixture 

 disposed upon a suitable carbon support between the terminals 

 of a powerful arc lamp. Upon the generation of the arc by 

 means of a current of 350 amperes action almost immediately 

 commenced, the mixture of boric anhydride and carbon fusing 

 and evolving a considerable amount of gas with effervescence. 

 The operation is concluded when the effervescence ceases, 

 when the current should be switched off and the product 

 allowed to cool. Carbide of boron is thus produced in the 

 form of black graphitoidal spherules, frequently aggregated so 

 as to resemble the shape of a bunch of grapes. The spherules | 

 NO. 1252, VOL. 48] 



possess a bright metallic lustre. They may be freed from 

 traces of the ingredients of the mixture used in their prepara- 

 tion by heating for a few hours in a platinum crucible, then 

 powdering, and repeatedly treating the powder with hydro- 

 chloric acid, water, a mixture of hydrofluoric and sulphuric 

 acids, and finally once more with distilled water. The powder 

 thus prepared yields numbers on combustion with chromate of 

 lead which agree closely with the formula above given. Carbide 

 of boron closely resembles graphite in outward appearance ; it 

 blackens the fingers in a similar manner, and the coating thus 

 transferred possesses the same bright metallic lustre and greasy 

 feel. Examined under the microscope it appears bluish black 

 and transparent, and reflects light with chromatic effects. When 

 heated to a high temperature the powder cakes together, form- 

 ing a soft mass, which is readily malleable and capable of being 

 rolled. At a very high temperature it completely fuses to a 

 liquid much resembling a molten metal. It burns only with 

 great difficulty in oxygen, but is combustible, as above 

 stated, with chromate of lead. It is insoluble in all the 

 ordinary solvents, but fused caustic or carbonated alkalies 

 attack it with formation of borate of the alkali and liberation 

 of carbon. 



Notes from the Marine Biological Station, Plymouth. — Last 

 week's captures include the Mollusca Lima Losconibii and 

 Pholadidea papyracea, and the Schizopoda Leptomysis gracilit 

 and a number of Erythrops e/egans. The floating fauna is 

 unusually rich in Diatoms and Dinoflagellates, and a few 

 Radiolaria are still to be seen. The larvje of Polynoe, Chatop: 

 terns and Terebella are fairly numerous, and Cyphonantes and 

 larval Lamellibranchs are plentiful. On the other hand the 

 larvx of Decapoda (esp. of Brachyura) are scarce, and a few 

 Ophiuria Plutei are the only representatives of the Echino- 

 derma. The more oceanic forms {Muggiaa, Podon and 

 Evidne, &c. ) have of late become increasingly scarce. The 

 Hydroid Aglaophenia tubulifera is now breeding, and a few 

 Erythrops elegans contain late embryoes in their brood- 

 pouches. 



The additions to the Zoological Society's Gardens during 

 the past week include a Wanderoo Monkey (Macacus silmus, 9 ) 

 from Cochin, presented by Capt. Morgan ; two Macaque 

 Monkeys [Macacus cynomolgtis, i ? ) from India, presented re- 

 spectively by Mr. John Cook and Mr. Stanley Sinclair ; a 

 Chacma Baboon {Cynocephalus forcarius, 9 ), two Common 

 ^^wiWs, [Coturnix communis) from South Africa, presented by 

 Capt. F. Baker; two Manatees (^a«a/»i a«;«r»V«, 9 etjau.) 

 from Manatee Bay, Jamaica, presented by Sir Henry A. 

 Blake, K.C.M.G. ; a Black -headed Lemur {Lemur brunneus, 9 ) 

 from Madagascar, presented by Miss Hoare ; a Rufous Rat 

 Kangaroo (Hypsiprymnus rujescens) from Australia, presented 

 by Kenneth Crawley, Esq., R.N. ; a Kite {Milvtis ictinus) 

 from the Canary Islands, presented by Mr. E. G. Meade- 

 Waldo, F. Z. S. ; two Purple Porphyrios {Porphyria cceruleus') 

 South-east European, presented by Mr. Joseph S. Whitaker, 

 F.Z.S. ; a Turtle Dove (Tiirtitr communis) British, presented 

 by Miss Alice L. West ; a Kinkajou {Cercolepies caudivolvultts), 

 a King Vulture {Gypagus papa Jew.), a Common Boa {Boa 

 constrictor) from South America, two Ospreys {Pandion 

 haliatus) from Hayti, W.I. ; two Rufous-necked Weaver 

 Birds {f/yphanlornis textor) from South Africa ; a Dunlin 

 {Tringa alpiniis) British, purchased ; a Burchell's Zebra 

 {Eijuiis burchelli, 9 ), a Wapiti Deer {Cervus canadensis, 9 ) 

 born in the Gardens. 



OUR ASTRONOMICAL COLUMN. 



A New Comet. — Edinburgh Circular (No. 40, dated Octo- 

 ber 19) informs us of the discovery of a comet by Mr. W. R. 

 Brooks, of Geneva, N. V., at I5h. 52m. local time, its place then 



