OcToBER 19, 1899] 
NATURE 
609 
was opened by Prof. Marshall Ward, who was followed by Sir 
Henry Roscoe, Prof. Armstrong, M. van Laar, Prof. Reynolds | 
| read the first report of his committee on the absorption spectra 
Green, Prof. Warington, M. Tanret, Prof. Francis Darwin 
and Dr. G. H. Morris. There is little doubt that the dis- 
cussion has led to a more exact recognition of the division | 
and relations of symbiotic changes, which should serve to 
develop the study of the subject. Prof. Marshall Ward, 
after considering the conditions under which symbiosis exists 
both in the vegetable and anima] kingdoms, passed to the | 
more special subject of symbiotic fermentations. Prof. Ward 
instanced the various grades of symbiotic association that 
may be recognised, suggesting a special nomenclature, and 
concluded his remarks with the consideration of the physiology 
of the subject. The many possibilities that may arise in the 
mutual life of symbiotic organisms—such as the provision of 
definite food material by one symbiont for the other, or the ad- 
vantage derived from a protective influence, or, finally, the 
exertion of a stimulating action—were discussed, with the con- | 
| and on isomorphism in benzene sulphonic derivatives. 
clusion that there is some evidence to support the hypothesis 
that one symbiont may stimulate another by excreting a body 
which acts as an exciting drug to the associated organism. The 
chemical aspect of the subject was concisely treated by Prof. 
Armstrong, who pointed out that there is an absence of positive 
evidence to show that one member of a pair of symbiotic | 
organisms does more than prepare the way for the other by 
effecting a change which the second is incapable of in- 
ducing. The possibility of chemical interaction playing a part 
in symbiotic changes and the hydrolytic function of enzymes 
were clearly brought out, and illustrations of allied changes of 
a purely chemical character instanced. Prof. Armstrong pointed 
out that no case has yet been observed in which a substance is 
attacked by a pair of organisms neither of which can attack it 
singly, and regarded it as probable that associated molecules 
undergo change under the influence of a single organism or 
agent which determines their association. Prof. van Laar, on 
the other hand, expressed the view that symbiosis was rather a 
case of parasitism. Dr. Calmette’s contribution on industrial 
symbiotic fermentations was read, in his unavoidable absence, 
by Sir Henry Roscoe. 
the methods for the conversion of starch into alcohol by the 
association of pure cultures of moulds with pure yeast cultures, 
and the industrial application of this symbiotic relation. Both 
in France and in Belgium thousands of tons of starch are now 
converted into alcohol by this method, and most favourable 
results have been obtained both as regards yield and quality. | 
In inorganic chemistry Prof. Dewar’s important experiments on | 
the solidification of hydrogen stands foremost; an account of 
these researches has already appeared in NATURE. Colonel 
Waterhouse contributed a note on a remarkable result he has 
observed on the exposure of metallic silver to light ; a visible | 
image results on the exposed plate after prolonged exposure, but 
the effect may be recognised in a very much shorter space of time 
by the development of the latent image produced. An important 
discussion on the proposal of establishing an International Com- 
mittee on Atomic Weights was initiated by Prof. F. W. Clarke 
a critical észemé of both the theoretical and practical aspects of 
the question. 
at the Congress of Chemists to be held in Paris next year, Prof. 
Clarke’s proposal for an International Committee aroused much 
interest ; but the exact scope of its work appeared difficult to 
define in the minds of Sir Henry Roscoe, Prof. Fittig, Sir 
William Crookes and others who participated in the discussion. 
The desirability of encouraging all capable of undertaking the 
redetermination of atomic weights was fully recognised, but such 
work could not be ordered. This view, of course, referred to 
the theoretical part of the problem ; Prof. Tilden’s suggestion 
regarding the desirability of an understanding as to the numbers 
to be chosen for ordinary use was somewhat lost sight of by 
many of the speakers, especially his important addendum that 
the values arrived at in atomic weight determinations are 
obtained under conditions which cannot be observed in daily 
laboratory practice, and that the adoption, therefore, of numbers 
regarded as the most exact does not of necessity contribute to | 
the exactness of ordinary analytical observations, Dr. Glad- 
stone’s report on the teaching of natural science in elementary 
schools was followed by an interesting discussion; Dr. Glad- 
stone, in conjunction with Mr. Hibbert, also contributed a 
paper dealing with some peculiarities in the drying of colloids 
such as the hydrates of silica, tin, titanium, iron and alumina. 
NO. 1564, VOL. 60] 
| by the Section for their further investigation. 
| carbon atom acid from glucosone. 
In this paper an account was given of | 
Tn view of the proposed discussion of the subject | 
The papers, reports, and discussions dealing with organic 
chemistry were of more than usual importance. Prof. Hartley 
and chemical constitution of organic substances, which, in 
addition to the work of the committee, contains a valuable 
summary of that of other investigators. The committee on the 
action of light upon dyed colours issued their final report, 
which completes a long series of important experiments carried 
out chiefly by Prof. Hummel. Prof. Armstrong opened a dis- 
cussion on laws of substitution, especially in benzenoid com- 
pounds, in which the conditions of substitution in amines and 
phenols were dealt with. The course of the reaction in those 
cases in which ortho- and para-compounds, on the one hand, 
and essentially meta-compounds, on the other, result were dis- 
cussed, and the possibility of the formation of intermediate pro- 
ducts in the former case which subsequently undergo isomeric 
change fully considered. Prof. Armstrong also contributed 
papers on the relative orienting power of chlorine and bromine, 
Ex- 
tremely interesting isomorphous relations have been observedi 
amongst these latter compounds, and a committee was appointed, 
Mr. Fenton read, 
a summary of his researches on oxidation in presence of iron, in. 
which the extension of his reaction to tartronic, lactic, glyceric 
and malic acids was referred to, and, in conjunction with Mr. 
Jackson, described the condensation products obtained from 
glycollic aldehyde under the influence of dilute alkali. @-Acrose 
appears to be formed when a I per cent. solution of caustic 
soda is used, whilst a starch-like product results when the alde- 
hyde is heated to 160-170. Messrs. Morrell and Crofts gave 
an account of further experiments on the action of hydrogen 
peroxide on carbohydrates in presence of iron salts, the most 
interesting result obtained being the formation of a dibasic six- 
Special interest centred in 
a paper by Mr. W. J. Pope on the influence of solvents on the 
optical activity of organic compounds, in which he traced the 
variations in the specific rotation of an optically active sub- 
stance dissolved in various solvents to the degree of association of 
the active compound, and on this association factor founded a 
method for determining whether a particular optically active sub- 
stance formsa liquid racemic compound with its optical antipode.. 
Mr. Pope also described a new method for resolving racemic 
oximes into their optically active components, and Dr. M. O. 
Forster gave an interesting account of his researches on the 
influence of substitution on optical activity in the bornylamine 
series. Dr. Forster also described some new derivatives of 
camphoroxime, the chief interest of which lies in their relation 
to certain oxidation products of camphor. Dr. C. A. Kohn 
and Dr. W. Trantom, in a paper on the action of caustic soda 
on benzaldehyde, showed that, in the absence of water or in the 
presence of an excess of aldehyde, benzyl-benzoate is formed as 
a product of the decomposition; its production points to the 
formation of an intermediate ortho-compound in the reaction 
commonly employed in the preparation of benzyl alcohol. 
Prof. Emerson Reynolds described some new silicon compounds 
in the form of a letter to Prof. Tilden, who himself contributed | obtained by the action of ethyl mustard oil on silico-phenyl- 
di-imide, and Prof. Ladenburg read a summary entitled ‘* The 
development of chemistry in the last fifteen years,” in which the 
advances of the various branches of the science during that 
period were dealt with. Of more general interest was a paper 
| by Prof. Clowes on intermittent bacterial treatment of raw 
sewage in coke beds, which was followed by one by Mr. W. 
Scott-Moncrieff on the place of nitrates in the biolysis of 
sewage. Both papers, as well as the report of the committee 
on water and sewage examination results, led to an interesting 
and useful discussion. In a paper on the chemical effect on 
agricultural soils of the salt-water flood of November 29, 1897, 
on the East Coast, by Messrs. T. S. Dymond and F. Hughes, 
| the remarkable result was recorded that although the proportion 
| of salt left on the soil was insufficient to prove injurious to the 
growing crops, the earth-worms in the soil were entirely re- 
moved, with the consequence that very few crops were worth 
harvesting the following year. This year nine-tenths of the salt 
originally present has disappeared from the soil, and young 
worms have again made their appearance, but still the condition 
of the soil remains unsatisfactory, the rate of percolation of 
water through the flooded soil being only half as rapid as through 
the unflooded. This the authors trace to the action of the 
chlorides of the sea water on the double silicates of the soil with 
the formation of silicate of alumina in a gelatinous condition, 
