474 



NATURE 



[August 29, 1878 



Picoline, CgHyN, on oxidation, yields a dicarbopyridenic acid, 

 C7H5NO4, which, on distillation with soda-lime, decomposes 

 into pyridine, C5H5N, and carbonic anhydride, 2CO2. It has 

 therefore the structural formula C5H3N(200H)._,, Attempts 

 to prepare lutidine, C^HjN, from the aldehyde of that acid, as 

 well as by the reaction 



CjHjNCCOOCHg).;; = C7H9N + 2CO2, 



failed, owing, in the first instance, to the small yield of alde- 

 hydes, and, in the second, to the total decomposition of the 

 product into pyridine, carbonic anhydride, and carbon. 



In spite of the failure of these attempts the author regards it 

 as probable that picoline is methyl pyridine; entidine, dimethyl 

 pyridine, from the following consideration : — The amount of 

 heat evolved in the formation of these bases is probably very 

 high. That heat, added to the amount evolved by the com- 

 bination of the base with an acid, is likely to be greater than the 

 total number of heat-units evolved by the oxidation of the base ; 

 hence these bases are unoxidisable in acid solution. But when 

 oxidised in alkaline solution, the amount of heat evolved by 

 oxidation is supplemented by that arising from the combination 

 of the resulting acid with the alkali, and then exceeds the heat 

 evolved during the formation of the base. The presence of 

 nitrogen therefore gives great stability to the molecule, and pre- 

 vents the methyl groups from being oxidised to carboxyl-groups, 

 as in the case of toluol, xylol, &c. At least three isomeric acids 

 of the general formula C7H5NO4 have been discovered, and it 

 is probable that as many as six are capable of existence. These 

 the author has named o, j8, and 7, dicarbopyridenic acids. The 

 o-acid is obtained by oxidising picoline or entidine, and the last 

 two from entidine. 



An attempt to pass from furfurol to pyridine by the scries of 

 reactions — 



C5H4O2, 

 Furfurol, 



C,He02, CsH^OCl, QHsONH,, 



Furfuryl Furfuryl Furfuryl 



alcohsl, chloride, amine, 



C6H«N, 

 Pyridine, 



was unsuccessful, owing to the instability of furfuryl chloride. 



From the stability of the pyridine group, and the instability 

 of the furfurol group, the author regards it as probable that the 

 constitution of the former is best represented by a closed, and 

 that of the latter by an open, chain. 



On Some of the Dei-ivaHves of Furfurol, by Dr. W. Ramsay. — 

 It was found impossible to prepare furfuryl chloride by the 

 action of phosphoric chloride, or of hydrochloric acid gas on 

 furfuryl alcohol, CjlIgOj, owing to a complete decomposition 

 of the organic matter, with separation of caibon. 



Furf urine, prepared by heating furfuramide and possessing 

 the same formula, C15H12N2O3 unites with methyl iodide, 

 forming the hydriodide of methyl-furfurine ; this salt, on treat- 

 ment with ammonia, deposits the base Ci5Hii(CH3)N203, as a 

 viscous oil, insoluble in water, but soluble in alcohol. The base 

 again unites with methyl iodide, giving the hydriode of dimethyl 

 fm-furine, C]5Hio(CH3)2N.^03HI, which is also decomposable by 

 ammonia with liberation of the base, dimethyl furfurine 

 CieHjo(CH3)2N203. This base appears also to be capable of 

 union with methyl iodide. 



Furfurine, then, appears to be a secondary base containing 

 two atoms of hydrogen replaceable by methyl. Whether more 

 can be replaced the author was unable to decide, as the loss by 

 repetition of the operation was very considerable. 



On the Thetines, by E. A. Letts. — Prof. Letts' experiments 

 were undertaken as a sequel to the research of Prof. Crum 

 Brown and himself, on dimethyl thetine and its compounds, and 

 with a view to the thorough investigation of the thetines as a 

 group — the phenomena attending their formation — the action of 

 heat and oxidising agents on them, and the difference in their 

 properties as the series is ascended. Incidentally Prof. Letts 

 has also studied the action of bromacetic acid on certain sulphides 

 of hydrocarbon radicals and the action of bromacetic and 

 iodacetic ethyl ether on sulphide of methyl. 



Notes on Aluminium Alcohols, by Dr. Gladstone and Mr. 

 Tribe, — In 1876 the authors described the joint action of alumi- 

 nium and iodine on alcohol, and two aluminium ethylates result- 

 ing from it. They now showed that a similar reaction takes 

 place with methylic alcohol, especially when the aluminium is 

 rendered more powerful by conjunction with deposited platinum ; 

 and that an analogous body is still more readily formed from 

 •amylic alcohol. These two substitution-products had not yet 

 been prepared in a pure condition, but the authors had succeeded 



in preparing the butylic compound in a satisfactory manner. 

 This aluminic butylate is a solid body at the ordinary tempera- 

 ture, but melts when heated, and is capable of distillation. It 

 is very soluble in anhydrous ether or benzole, from which it 

 separates on evaporation without crystallising. It is decom- 

 posed by water, butylic alcohol and alumina being produced. 

 Its composition was found to be Al.,(C4HgO)g. There is also 

 evidence of an intermediate compound, soluble in water, which 

 is probably homologous with the aluminic iodo-ethylate 

 AlJjlQHsOa. 



On the Amounts of Sugar contained in the Nectar of Various 

 Flotvers, by Alex. S. Wilson, M.A., B.Sc. — Nectar, the sweet- 

 tasting fluid found within the cups of insect-fertilised flowers is 

 of use to the plant by affording an inducement whereby insects 

 are attracted to visit the flowers. By this means cross-fertilisa- 

 tion is effected, as bees, butterflies, and other insects bring 

 with them pollen from other flowers adhering to their bodies 

 which they deposit on the stigmas. Mr. Dar^vin has shown 

 experimentally what an additional amount of vigour is thus 

 conferred on the resulting seeds in contrast with the degenerating 

 effect of continuous inbreeding. Very often this sweet fluid is 

 exuded from special glands, but in other cases from portions 

 of the flow er that do not seem to have been specially adapted for 

 this purpose. Morphologically nectaries may represent very 

 different structures, but not unfrequently they are of the nature 

 of an aborted organ such as a petal or stamen. It is a disputed 

 point among biologists whether this saccharine matter is a true 

 secretion or simply an excretion of effete matter from vegetable 

 cells — a bi-product of the chemical changes taking place within 

 these cells. Nectar is of course the source whence the bee 

 derives honey, but it also affords sustenance to many different 

 kinds of insects as well as humming-birds. The bright colours 

 of flowers as shown by Sir John Lubbock's experiments serve for 

 the guidance of insects to them, and the odours which they emit 

 fulfil the same end. The markings on a flower's petals, too, 

 always converge towards the nectar. The importance of these 

 guides to insects will be apparent from the following estimations 

 which show how indispensable it is that as little time as possible 

 should be lost by an insect while collecting honey. It must be 

 remembered also that in order to protect the nectar from rain it 

 is usually contained in the least accessible part of the flower. 

 The formation of nectar is observed to take place most freely in 

 hot weather, so great, however, is the economy of the plant that 

 it is only formed at the time when insects' visits would be bene- 

 ficial, i.e., when the anthers are shedding their pollen or when 

 the stigma is mature. Biologists believe that the -visits of bees, 

 butterflies, and other insects have in past time exercised an im- 

 portant influence in modifying the size, shape, colour, &c,, of 

 flowers. The following determinations are of interest as showing 

 to what extent this action goes on and as a help towards ascer- 

 taining the value of this factor : — 



Sugar in Flowas. 



Total. Fruit, Cane. 



1. Fuchsia, per flower mmg. 7"59 i '69 5*9 



2. Everlasting Pea, per flower... ,, 9*93 8*33 1*60 



3. Vetch, per raceme ,, 3'i6 3'i5 'oi 



4. ,, single flower ... ,, '158 '158 



5. Red Clover, per head „ 7*93 5'95 1*98 



6. „ „ floret „ -132 -099 -033 



7. Monkshood, per flower ... ,, 6'4i 4*63 178 



8. Claytonia almoides, ^Qv Aowev ,, •413 '175 '238 



Approximately, then, 100 heads of clover yield '8 grm. sugar or 

 125 give I grm. or 125,000 i kilo sugar, and as each head con- 

 tains about sixty florets it follows that 7,500,000 distinct flower 

 tubes must be sucked in order to obtain i kilogrm. sugar. Now 

 as honey roughly contains 75 per cent, of sugar, i kilo, is equi- 

 valent to 5,600,000 ilowers in round numbers, or say two-and-a- 

 half millions of visits for I lb. of honey. Another point worthy 

 of note in these results is the occurrence of what appears to be 

 cane-sugar, and that in the case of fuchsia in the proportion of 

 three-fourths of the whole. This is remarkable, as honey is 

 usually supposed to contain no cane-sugar, its presence being 

 generally held as certain evidence of adulteration. The question 

 therefore arises whether this change, which occurs while the sugar 

 is in the bees' possession, be due to the action of juices with 

 which it comes in contact while in the honey-bag, or whether 

 on account of the acid reaction of nectar it may not take place 

 spontaneously. 



Notes on Waters from the Severn Tunnel Springs, by W. Lant 

 Carpenter. — The plans for the construction of this tunnel had 



