SCIENCE-GOSSIP. 



25 



however, are bound together in an almost incon- 

 ceivably complex manner. We know that the 

 green leaves manufacture carbohydrates (com- 

 pounds of carbon, oxygen and hydrogen) from 

 carbonic acid gas and water under the influence of 

 sunlight. We are also aware that the roots absorb 

 from the soil the nitrates (compounds of oxygen 

 and nitrogen) which, thanks to micro-organisms, 

 have appeared there, and that the sulphur com- 

 pounds of soil enter the plant by the same route. 

 In other words, we know that within the plant are 

 present materials, available as food, which contain 

 between them the same elements as a proteid ; but, 

 starting from this consideration, we have hitherto 

 been unable to explain any of the steps which lead 

 to the formation of the complex organic nitroge- 

 nous compounds from these substances. Pfliiger 

 long ago (1S75) held the purely hypothetical view 

 that there was a close connection between the 

 proteids of living protoplasm and cyanogen, in fact 

 that in living proteids the nitrogen was associated 

 with carbon in the form of cyanogen (in which two 

 atoms of carbon are united to two atoms of nitrogen) . 

 Treub has now made it certain that in Pangmni cdule 

 hydrocyanic or prussic acid (carbon, hydrogen 

 and nitrogen united together) is the first visible 

 nitrogenous compound to appear in the constructive 

 processes. He has found that both in the cortex 

 and pith of the stem there are special cells particu- 

 larly rich in prussic acid. This substance can also 

 be detected in the pericycle. In the leaves it is 

 usually to be found in all the parenchyma cells, in 

 the flowers and fruits it is also present. The great 

 channel along which hydrocyanic acid moves from 

 part to part of the plant is the soft base or phloem. 

 If the outer layers of the leaf-stalk be cut through, 

 or conduction in any other way hindered, an 

 accumulation of prussic acid takes place in the 

 blade of the leaf whilst none of the acid can be 

 detected for some distance below the point of 

 section. By a careful study of such cases as these, 

 it could be definitely established that hydrocyanic 

 acid is formed in the leaf and conveyed away to 

 other portions of the plant by the soft bast. 

 Another interesting fact that was determined was 

 that those special cells of the cortex or pith, filled 

 with prussic acid in their earlier days, became 

 the seats of proteid accumulation in later times. 

 Among the factors necessary for the formation of 

 prussic acid, two were found to be absolutely 

 essential (i) That carbohydrates be present; 

 (2) That a supply of nitrates be forthcoming to 

 the leaf. Light it was found was not directly 

 necessary. Treub employed the "prussian-blue 

 test," familiar to all chemists in ascertaining the 

 presence or absence of hydrocyanic acid in any 

 tissue of the plant. The position, then, that we 

 have reached through Treub's researches, is that in 

 Pangium cdule, pruisic acid — a comparatively simple 

 compound — is the first visible nitrogenous organic 

 body to be synthesised in the plant ; whether this 

 is the case throughout the vegetable kingdom or 

 whether it is the plan adopted in this single instance 

 only, or in one or two other plants as well, remains 

 for the future to decide. Any who feel interested 

 in the subject should certainly refer to Treub's 

 original article (" Sur la localisation, etc., de I'acide 

 cyanhj'drique dans le Paiigiiou ediile" Ann. du 

 Jardin Botanique de Buitenzorg. Vol. xiii., 1895, 

 pp. 1-S9), or to the report of the Paper he read 

 before the British Association at Ipswich last year, 

 or to the admirable summary in the " Botanische 

 Zeitung " (Bot. Zeit., No. 7, 1S96, p. 102).— RudolJ 

 Beer, Elvnvood, Bickley, Kent. 



Lepiddptkra in- NoKWAV.^-Can any one lell me 

 through the pages of Science-Gossip what lepidop- 

 tera 1 am likely to find near the Nordfjord in 

 August, and if there are many species then out in 

 that region ? — {Rev.) J. M. Hick, Jrimdon Vicarage, 

 Trimdoii Grange, R.S.O. 



Elephus Africanus. — Can any reader imform 

 me through your pages where I might be able to 

 obtain some information relative to the occurrence 

 of Elephus Africanus in the fossil state in England ? 

 If so he would greatly oblige.-—/. H. Cooke, 123, 

 Monks Road, Lincoln. 



Pied-wagtail in Winter. — An apparently 

 solitary specimen of the pied-wagtail is spending 

 the winter here and is constantly to be seen 

 searching for food in the garden and about the 

 buildings. Is it not somewhat unusual for this 

 bird to be found so far north at this time of the 

 year. — Vernon B. Crowther-Beynon, The Grange, 

 Edith Weston, Stamford ; February gth, iSg6. 



Little Auk in Sussex. — As an addendum to 

 Professor Newton's article on page i of the last 

 volume of Science-Gossip, it is perhaps worth a 

 note in your pages, that a group of eight specimens 

 of this bird was exhibited at West Croydon Hall, 

 by Mr. Thorpe, the Croydon taxidermist, last 

 autumn, which had been taken near Hastings 

 during the great frost in the early months of 1S95. — 

 Ed. A. Martin, 62, Bensliam Manor Road, Thornton 

 Heath. 



Prehistoric Human Re.mains. — In a note 

 (SciExcE-GossiP, vol. ii., N. S., p. 313). Mr. Kane 

 remarks that it is curious that no reference to 

 the interesting find of prehistoric human remains 

 near Le Puy, Auvergne, is made by writers 

 of antiquity of man. He appears to have over- 

 looked Lyell's "Antiquity of Man" in which 

 there is a pretty full account (3rd ed., 1S63. p. 

 194). Scrope, in his "Geology and Extinct Vol- 

 canoes of Central France (2nd ed., 185S, p. 

 1S2), also mentions the subject, and gives two 

 sketches of the spot where the fossils were found.— 

 W. J. Atkinson, 76, Christchurch Road, Streathant Hill, 

 London, S.W. 



Where not to Find Coal. — A sentence in your 

 review of the " Missouri Geological Survey " reminds 

 me of the attempt which was made last year to find 

 coal in Silurian strata at St. Kilda. 'Melbourne. 

 Australia. An old lady left a considerable sum of 

 money for the boring to be made with this object 

 in view. Certainly it cannot be said that coal has 

 never been found in Silurian rocks, but on the 

 other hand it does not seem credible that anyone 

 with anv pretence to a little geological knowledge, 

 would have had a trial boring made for coal through 

 strata of that age. As the author of the sur\-ey 

 says, a verv little study of the strata soon deter- 

 mines whether or not the rocks of any given district 

 are likely to furnish coal. The Silurian strata of 

 St. Kildare did not.— £<;. A. Martin, 62, Bensham 

 Manor Road, Thornton Heath. 



