14^ 



NA TURE 



{Dec, 12, 1S89 



" He leaves the question as to the origin of the bacteroids by 

 l)udding or otherwise quite undecided, having failed to satisfy 

 liimself whether my suggestion is right or not ; at the same 

 tim^, he fully agrees with me and others in believing that these 

 tiny bodies must be the infecting agents, easily and abundantly 

 ■distributed as they are in the soil, water, &c." 



The author concludes by saying : — 



" I think it will be admitted by all who study the literature 

 of this subject, that the only real point at issue between Praz- 

 mowski and myself is the nature of the bacteroids and their origin 

 from the filaments. I interpreted them as extremely minute 

 budding 'gemmules,' and not bacteria ; Prazmowski, with Beyer- 

 inck, regards them as true Schizomycetei. We have all alike 

 failed to actually see the process of budding or fission, a fact 

 which will surprise no one who has examined these extremely 

 minute bodies, which are, as Beyerinck rightly puts it, among 

 the smallest of living beings. 



" The fact of infection, and the mode of infection, by means of 

 a hypha-like filament passing down the root-hair were definitely 

 established by myself in 1887, and it is satisfactory to find it 

 confirmed in every essential detail by Prazmowski. Our views 

 as to the symbiosis, the struggle between the protoplasm and 

 the 'gemmules' (or 'bacteroids') are the same; though Praz- 

 mowski and Beyerinck carry the matter a step further in 

 definitely inferring the absorption of the conquered bodies of the 

 latter, a point in part supported by some of my experiments. 



"As to the occurence, origin, and structure of the tubercles, 

 Prazmowski's account is simply in accordance with my own ; and 

 it is interesting to note how many points of detail — the distortions 

 of the root-hairs, the relations of the branching filaments to the 

 nuclei and cell-contents, and those of the incipient tubercle to 

 the end of the filament, for example — are confirmed by him." 



Chemical Society, November 7. — Dr. W. J. Russell, 

 F.R.S., President, in the chair. — The following papers were 

 read : — Isolation of a tetrahydrate of sulphuric acid existing in 

 solution, by Mr. S. U. Pickering. The freezing-points of 

 mixtures of sulphuric acid and water form three distinct 

 curves representing the crystallization of water, of the hydrate, 

 H2SO4 -{- HoO, and of sulphuric acid, and the highest point of 

 each of these curves is in exact correspondence with the com- 

 position of the substance which crystallizes out. Solutions 

 containing between 40 and 75 per cent, of sulphuric acid had 

 not hitherto been frozen ; but it appeared to the author that if 

 his former deductions from the irregularities in the curves 

 ■representing the densities and other properties of the solutions 

 of the acid were correct, an independent curve representing the 

 crystallization of a new hydrate should occupy this interval, 

 and that this new hydrate should have the composition 

 H2SO4 -i- 5IH2O, or H2SO4 -I- 4H2O. Experiment has proved 

 it to be the latter. The two branches of the new curve rise 

 from about - 80°, and meet in a sharply marked angle at a point 

 ■corresponding with the composition of the tetrahydrate, the 

 temperature at which this point is reached being - 25°. The 

 tetrahydrate forms large, well-defined, hard crystals. The 

 author regards the isolation of this hydrate as affording fresh 

 confirmatory evidence of the hydrate theory of solution. — 

 Additional observations on the magnetic rotation of nitric acid, 

 and of hydrogen and ammonium chlorides, bromides, and iodides 

 in solution, by Dr. W. H. Perkin, F. R S. In his previous 

 experiments, the author has limited his observations on nitric 

 acid to the pure acid HNO3 ; he has now examined a somewhat 

 diluted acid, and the results indicate that HNOj unites with 

 water, forming an acid analogous to orthophosphoric acid, viz. 

 •(OH)3NO. The experiments on hydrogen chloride, bromide, 

 and iodide were originally made on single samples in a very 

 concentrated solution of each. These gave abnormally high 

 results— rather more than twice the values calculated for the 

 pure compounds — but on examination of solutions of different 

 strengths, it was found that the rotation increases up to a dilution 

 equivalent to about six or seven molecular propoKtions of water, 

 to one molecular proportion of hydride, the value then remaining 

 practically stationary. To see whether the solvent had any 

 influence, a solution of hydrogen chloride in isoainyl oxide was 

 examined, and was found to give values nearly identical with 

 those calculated from the chlorine derivatives of the paraffins ; 

 and there can be little doubt that, if the other hydrides could be 

 examined in a similar way, analogous results would be obtained. 

 As union with water should reduce the rotations, the results are 

 at present inexplicable. The compounds with ammonia and 

 the compound ammonias have also been further examined ; the 



results are remarkable when considered in relation to those 

 afforded by the hydrides, as the rotations found, instead of 

 being those calculated from the results obtained in the case of 

 the paraffin derivatives, or those found in the case of hydrogen 

 chloride dissolved inisoamyl oxide, nearly correspond with those 

 required on the assumption that the hydrides are present in 

 aqueous solution together with ammonia. The rotations, 

 however, do not vary with the strength of the saline solutions. 

 The author's explanation of this is that when the salts are 

 dissolved in water, they dissociate almost entirely into the 

 hydride and the amine, the hydride undergoing an increased 

 rotation on account of its being in aqueous solution. In the 

 case of triethylamine hydrochloride the numbers are lower, and 

 there is evidently less dissociation ; and in the case of tetrethyl- 

 ammonium chloride little or no dissociation appears to take 

 place. Solutions of ammonium iodide and diethylamine hydro- 

 chloride in absolute alcohol gave somewhat lower numbers 

 than aqueous solutions, indicating somewhat smaller, although 

 still large, amount of dissociation. Ammonium nitrate and acid 

 ammonium sulphate in aqueous solution give numbers agreeing 

 closely with the calculated values, and apparently do not 

 dissociate to any appreciable extent. In the discussion which 

 followed the reading of this paper, Dr. Gladstone, F.R.S., 

 stated that, on examining Dr. Ferkin's solution of hydrogen 

 chloride in isoamyl oxide, he found that the refraction and 

 dispersion values deduced for the chloride are very much smaller 

 than those afforded by aqueous solutions. — Phosphoryl trifluoride, 

 by Prof. T. E. Thorpe, F.R.S., and Mr. F. J. Hambly. 

 Phosphorus oxyfluoride, POF3, may be easily and conveniently 

 made by heating a mixture of cryolite and phosphoric oxide, 

 and collecting the products at the mercurial trough — Acetylation 

 of cellulose, by Messrs. C. F. Cross and E. J. Bevan. On heating 

 cotton cellulose with acetic anhydride and zinc chloride, a product 

 is obtained which appears to be a pentacetyl derivative of 

 cellulose. The compound is very stable, and on alkaline 

 hydrolysis yields a substance having the properties of a normal 

 cellulose. It would therefore appear that all the oxygen of the 

 cellulose molecule acts as hydroxylic oxygen, and, in view of this 

 result, a reconsideration of the present ideas as to the constitution 

 of cellulose is rendered necessary. — Action of light on moist 

 oxygen, by Dr. A. Richardson. The presence of liquid water 

 very much facilitates the oxidation of many substances under the 

 combined influence of sunlight and oxygen, but if the water is 

 present as aqueous vapour, the decomposition is exceedingly 

 slow, and in some cases is entirely arrested. The author finds 

 that peroxide of hydrogen is formed when water containing pure 

 ether, or pure water acidified with pure sulphuric acid, is exposed 

 to light in an atmosphere of oxygen, and draws the conclusion 

 that the oxidation of substances under the influence of light 

 involves in many cases initially an oxidation of water to hydrogen 

 peroxide, and that the oxidation of the compound is the result 

 of a secondary interaction between it and the hydrogen peroxide. 

 In the discussion which followed the reading of the paper. Prof. 

 Armstrong pointed out that, whilst Dr. Richardson assumed that 

 water was directly oxidized when mixed with ether and exposed 

 to oxidation, Mr. Kingzett had argued — and in the case of 

 turpentine had adduced weighty experimental evidence — that 

 the hydrogen peroxide was a secondary product formed by the 

 action of water on an organic peroxide. The use of ether or 

 sulphuric acid, which Dr. Richardson had added with the object 

 of protecting the peroxide, was to be deprecated, since hydrogen 

 peroxide in weak solutions was comparatively stable ; no 

 satisfactory evidence had been adduced that the peroxide is 

 formed in the absence of a third substance when water and 

 oxygen are exposed to light. Prof. Dunstan remarked that he 

 had found that hydrogen peroxide was not formed when pure 

 ether was used, although a substance was obtained which was 

 capable of liberating iodine from potassium iodide. The 

 President said that in experiments which he and Captain Abney 

 had made together on the fading of water-colours, the action of 

 aqueous vapour had been most strikingly apparent ; colours 

 were found to be stable on exposure to light in dry air, which 

 were considerably affected when aqueous vapour was present. — 

 a-;8-dibenzoylstyrolene and the constitution of Zinin's lepiden 

 derivatives, by Prof. F. R. Japp, F. R. S., and Dr. F. Klinge- 

 mann. The authors have continued their investigation of the 

 interactions of dibenzoylstyrolene (anhydracetophenonebenzil), 

 and find that there is an almost perfect parallelism in behaviour 

 between it and one of the three isomeric oxy epidens prepared 

 by Zinin, viz. the "acicular oxylepiden" melting at 220°. 

 The various compounds obtained by them stand to the corre- 



