46 



NA rURE 



[May 8, 1890 



that so long as the bacteria were fed with proteids they refused 

 to excrete the diastatic enzyme which they produce in abundance 

 wheii only carbohydrates are at their disposal. Prof. Green said 

 that in the case of the date-stone his observations led him to 

 believe that the enzyme was independent of the endosperm, and 

 that probably it was located in the epithelial layer. But in castor 

 oil seeds not only the embryo but also the endosperm cells ap- 

 peared to be possessed of vitality, the fatty matter of the lalter 

 -undergoing cliange even when not subject to the action of the 

 embryo ; probably the enzyme was present in the form of an 

 enzymogen, as extracts of the seeds were rendered active by 

 acids. Prof. Armstrong remarked that the authors had shown 

 that in the plant maltose was converted into cane-sugar ; dextrose, 

 according to their observations, did not undergo conversion into 

 •cane-sugar, but gave invert-sugar — that is to say, it Vjecame par- 

 tially converted into Isevulose, these constituents of cane-sugar 

 being apparently incapable of interacting. It was known from 

 Emil Fischer's work that dextrose could be converted into Isevu- 

 lose, and that maltose was an etheric compound of the acetal 

 type, formed from two molecules of dextrose, one of which acted 

 as aldehyde, the other as alcohol ; it was conceivable that if the 

 "dextrose residue " in maltose underwent a change comparable 

 with that which is involved in the conversion of dextrose into 

 Isevulose, a compound would be obtained which if not identical 

 with cane-sugar would be convertible into it by hydration and 

 subsequent dehydration. The authors had spoken of the maltose 

 becoming incorporated with the protoplasm from which the 

 cane-sugar was then elaborated ; perhaps the effect was com- 

 parable with that exercised by phenylhydrazine in effecting the 

 conversion of dextrose into Isevulose through the agency of the 

 osazone. Dr. Lauder Bruntonand Mr. Thiselton Dyer also to jk 

 part in the discussion. — The formation of indenederivatives from 

 <librom-a-naphthol, by Prof. R. Meldola, F.R.S., and Mr. F. 

 Hughes. — The action of hydrochloric acid on manganese di- 

 oxide ; manganese tetrachloride, by Mr. II. M. Vernon. Con- 

 trary to the statements of Pickering (Chem. Soc. Trans., 1879, 

 654), the author finds that the original pr)duct of the action of 

 hydrochloric acid on manganese dioxide is ma-iganese tetra- 

 chloride, and that at first no free chlorine is formed. 



April 17.— Dr. W. J, Russell, F.R.S., President, in the 

 chair. — The following papers were read : — Phosphorous oxide. 

 Part I, by Prof. T. E. Thorpe, F.R.S., and Mr. A. E. 

 Tutton. The authors describe a method of making phos- 

 phorous oxide by burning phosphorus in air. Pure phos- 

 phorous oxide crystallizes in thin monoclinic prisms, melts at 

 22°'5, solidifies at 2i^ and boils unchanged in an atmosphere of 

 ■nitrogen or carbon dioxide at 1 73°. When heated at 300°, it 

 decomposes, and at 440° is wholly converted into phosphorus 

 and phosphorus tetroxide : 4P4O6 - 6P2O4 -f P4. Phosphorous 

 oxide is readily acted on by light, and in bright sunshine its 

 colour rapidly becomes yellow, and eventually dark red, the 

 violet rays being most active in effecting the change. Its 

 molecular weight, as determined by Hofmann's and Raoult's 

 methods, corresponds with the formula P40g ; phosphorous 

 oxide, therefore, in this respect is analogous to arsenious and 

 antimonious oxides. The thermal expansion of liquid phos- 

 phorous oxide is expressed by the formula — 



V = I -t- o'039i377^ - o-Ogiii75/- -I- 0-0338607 -f^ ; 



its relative density at the boiling-point is I '6859, whence its 

 molecular volume = I30'5 ; and its molecular refraction for A 

 (\ = 7604) at 27°*4 is 60*5. Contrary to the usual statement of 

 the text-books, cold water has very little action on phosphorous 

 oxide : many days elapse before even a small quantity is dis- 

 solved ; it then forms phosphorous acid. Hot water acts upon 

 it with explosive violence, forming the red sub-oxide, phosphoric 

 acid, and spontaneously inflammable phosphoretted hydrogen. 

 Phosphorous oxide spontaneously oxidizes to phosphorus pent- 

 oxide on exposure to air or to oxygen, and the pi'ocess of oxida- 

 tion is attended under diminished pressure by a faint luminous 

 glow ; ozone is not formed as the oxidation proceeds. On gently 

 warming the oxide in oxygen, the glow gradually increases in 

 intensity until it passes into flame. . In contact with ozone, 

 phosphorous oxide glows at the ordinary temperature and 

 pressure. Phosphorous oxide has a well-marked physiological 

 effect, and it is not improbable that the action hitherto attributed 

 to phosphorus, especially as regards its influence on the glyco- 

 genic functions of the liver and on tissue change, may be really 

 due to this substance. The fumes from phosphorus consist 

 iargely of phosphorous oxide, and the odour of the product 



obtained by drawing air over phosphorus without allowing it to 

 ignite is identical with that of the pure oxide ; it is, indeed, 

 highly probable, as Schonbein long ago surmised, that phos- 

 phorus vapour, as such, is odourless, and that the smell which 

 phosphorus ordinarily possesses is a mixture of that of ozone and 

 of phosphorous oxide.— The action of chlorine on water in the 

 light, and the action of light on certain chlorine acids, by Prof. 

 A. Pedler. As a general result of a number of experiments, it 

 is found that, even in very strong tropical sunlight, water and 

 chlorine interact to but a very slight extent when the proportion 

 is about loo H^O : Q\ ; when the ratio is about 150 II2O : CI. 

 action takes place to the extent of perhaps 50 per cent., and 

 when niore than 400 H.^ : Q.\, to about 80 per cent, of the 

 theoretical. Chlorine water containing about 708 HgO : CU when 

 exposed to direct tropical sunlight decomposes practically 

 entirelyin the sense of the equation 2H.,0 + 2Q,\ = 0^-1- 4HCI, 

 an exceedingly small amount of chloric acid tjeing formed ; but 

 when exposed in a south aspect to strong diffused daylight, gives 

 much less oxygen and a variable amount of hypochlorous 

 or chloric acids, very little oxygen but an increased amount 

 of hypochlorous or chloric acids being formed when it is 

 exposed in a north aspect to moderate diffused daylight. Hypo- 

 chlorous acid, on exposure to light in dilute solutions, yields 

 both oxygen and chloric acid, the proportion of oxygen being 

 larger, the greater the intensity of the light. Solutions of chloric 

 acid undergo little or no change. The author concludes that 

 the action of chlorine on water is in its first stage similar to that 

 which it exercises on cold, dilute aqueous potash or soda, and 

 in its second stage to that on more concentrated hot solutions of 

 these alkalis, — Note on the explosion of hydrogen sulphide and 

 of carbon bisulphide with air and oxygen, by the same. The 

 author finds that when a mixture of hydrogen sulphide, air, and 

 oxygen is exploded, a normal result is obtained, sulphur dioxide 

 and water being formed. But when carbon bisulphide vapour 

 is similarly treated, a not inconsiderable proportion of the nitro- 

 gen of the air becomes oxidized, and sulphuric compounds are 

 formed under the combined influence of the oxides of nitrogen 

 and sulphur and of the moisture present. — The action of light 

 on phosphorus, and on some of the properties of amorphous 

 phosphorus, by the same. The author brings forward evidence 

 to show that the term "amorphous phosphorus" is a distinct 

 misnomer, and that, so far from the commercial amorphous 

 phosphorus constituting a separate allotropic modification of the 

 element, it is in reality the same substance as the form called 

 rhombohedral or metallic phosphorus ; the very slight difterences 

 in character noticed between the substances in question being 

 explained by the difference in the state of (division and the 

 slight variations conditioned by their mode of formation. The 

 change of red into ordinary phosphorus does not take place 

 below 358° ; above this the change takes place in vacuo, but 

 exceedingly slowly, even at 445°.— The action of phosphoric 

 anhydride on fatty acids, by Dr. F. S. Kipping. Heptylic acid 

 yields 25-33 per cent, of dihexyl ketone when heated with 

 phosphoric anhydride. 



Royal Microscopical Society, April 16. — Dr. C. T. 

 Hudson, F.R.S., President, in the chair. — Mr. J. Mayall, Jun., 

 called attention to a spiral ruling on glass, sent by Mr. P. Hraham, 

 of Bath, which had been produced in an ordinary lathe, the 

 diamond point being adjusted on the slide rest ; also to a series 

 of photomicrographs of diatoms, sent by Mr. T. Comber. 

 These were of special interest from the fact that they were pro- 

 duced with sunlight, by which the maximum resolving power of 

 the objective was obtained. — Mr. Mayall referred to an improved 

 form of fine-adjustment, constructed and exhibited by Messrs. 

 Powell and Lealand, in which the chief aim had been to construct 

 a fine-adjustment which should combine extreme sensitiveness 

 of action with accuracy and probable durability beyond what 

 had previously been obtained. The essential feature was the 

 application of what watchmakers would term a " jewelled move- 

 ment." The whole of the contact surfaces by which the fine- 

 adjustment was actuated consisted of polished steel and agate, 

 the intention being to reduce the friction as much as was con- 

 sistent with steadiness of motion. The result attained was 

 undoubtedly an improvement on the old system, though the cost 

 would probably limit the application to the few instruments re- 

 quired for very special and difficult investigations in microscopy. 

 For high-class photomicrographic work, or where preparations 

 had to be retained under observation for long periods of time, 

 the new mechanism should be particularly useful, for the greater 

 solidity of the general construction clearly pointed to greater 



