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THE CHEMICAL NEWS, July 30, 1909 



THE 

CHEMICAL NEWS 



AMB 



JOURNAL OF PHYSICAL SCIENCE. 



WITH WHICH IS INCORPORAT-BD THB "CHBMICAL OAZBTTB." 



% |0umal 0f Urartirai C^jemistrj) 



IN ALL ITS APPLICATIONS TO 



PHARMACY, ARTS, AND MANUFACTURES. 



EDITED BY 



SIR WILLIAM CROOKES, D.Sc, F,R.S., &€, 



VOLUME XCIX— 1909. 




LONDON : 
PUBLISHED AT THE OFFICE, 16, NEWCASTLE STREET, FARRINGDON ST., 

E.G. 

AND SOLD BY ALL BOOKSELLERS. 



UDCCCCIX. 



Ghbmical Nbws, 
July 30, igog I 



LONDON : 

PRINTED BY EDWIN JOHN DAVEY, 

16, NEWCASTLE STREET, FARRI^^GDON STREET, 

E.C, 



TH E CHEMICAL NEWS 



VOLUME XCIX. 



EDITED BY SIR WILLIAM CROOKES, F.R.S., S^. 



No. 2562.— JANUARY i, 1909. 



TANTALUM, NIOBIUM, AND TITANIUM : 
Observations on.* 

Part II. — On the Openino-up of Minerals containing 
THESE Bodies. 

13y W. U. GILES, IM.C. 

From the time of the discovery of niobium by Hatchett in 
1801 and of tantalum by Ekeberg in 1802, several methods 
have been proposed for the extraction of these bodies from 
the minerals in which they are found. These methods 
classified are : — 

1. Fusion with alkaline hydroxides: Ekeberg (Rose and 

others). 

2. Fusion with potassium carbonate and borax (Wol- 

laston). 

3. Treating with hydrofluoric acid or fusing with potas- 

sium bifluoride (W. Gibbs, Lawrence Smith, and 
Marignac). 

4. Treating finely powdered minerals mixed with carbon 

with chlorine at a red heat (Ste. -Claire Deville). 

5. Heating minerals mixed with carbon in an electric 

furnace (Moissan). 

6. Fusion with potassium bisulphate (Berzelius, Rose). 

Lawrence Smith and Rose also use sodium 
bisulphate and ammonium bisulphate. 

A short review of these processes and their respective 
advantages and defects is appended : — 

Method No. i. — With regard to this process, Rose states 
that it would probably be preferable to any other if it did 
not require the use of silver crucibles, which are rather 
strongly attacked by caustic alkalis in a fused state. 
Another disadvantage is that only a very moderate heat 
can be used with silver vessels, and consequently there are 
produced acid salts insoluble in water which have to be 
fused again with fresh alkali to render them soluble. I 
have made many experiments on these lines with 
columbites, tantalites, and similar minerals, using, instead 
of the silver vessels, platinum crucibles lined on the interior 
with pure gold. With these crucibles higher temperatures 
can be obtained, but still the results are unsatisfactory. 
The fused alkali climbs the sides of the crucible very per- 
sistently and volatilises in white clouds, much insoluble 
acid salts are formed, and if manganese is present the gold 
crucible is attacked and gold is found in the solutions sub- 
sequently obtained. Wrought iron crucibles were also 
tried, but the " climbing " of the fused materials was even 
worse than with the gold crucible, and extended sometimes 

* The first part of this Paper appeared in Chemical News, vol, 
xcv., p. I et seq. 



almost to the bottom of the outside of the crucibles, though 
I these were only half-full at the start. The following 
quantitative experiment was made on 5 grms. of very finely 
povydered and pure Australian tantalite (sp. gr. 7-24), 
I which was heated with successive charges of pure potas- 
I slum hydrate containing 723 per cent of K^O. After each 
j fusion the mass was thoroughly extracted with water, the 
I acids were precipitated from the alkaline solution with 
I dilute sulphuric acid mixed with sulphurous acid, the whole 
boiled, and the acids filtered, washed, and then strongly 
ignited, with addition of ammonium carbonate, to a constant 
weight. The matter insoluble in water — oxides of iron, 
: acid salts, &c. — was also heated with dilute sulphuric and 
sulphurous acid, filtered, washed and ignited, weighed, and 
then fused again with fresh caustic potash. (See Table I.). 
This table shows that, starting with 5 grms. tantalite and 
1 10 grms. of potassium hydrate, a fusion lasting three hours 
I and ending with a red heat, only rendered fbgs grms. of 
I the acids soluble in water out of a total of 4"i34 grms., or 
1 less than one-half, and that after a second fusion of the 
residue with 6 grms. more alkali there still remained in- 
soluble 084 grm. which contained tantalic and niobic 
equal to nearly 14 per cent of the total amount present, 
and that at least four successive fusions would be neces- 
; sary to entirely decompose the mineral. The disadvant- 
' ages of this mode of procedure are obvious, a very large 
amount of alkali is employed, and much time and mani- 
: pulation is necessary. I shall show further on that these 
j defects arise from the fact that it is impossible to raise the 
temperature of the caustic potash sufficiently high to 
cause the easy formation of tantalates and niobates 
soluble in mater. In fact, the alkali distils away and 
" chmbs " the crucibles before the requisite heat can be 
obtained. After many trials I abandoned this method 
with some reluctance, since, as Rose points out, the metallic 
acids thrown down from soluble tantalates and niobates by 
precipitation with acids are always much more pure than 
those obtained by fusion with potassium bisulphate and 
exhaustion with hot dilute sulphuric acid. It is curious, 
however, to note that these successive fusions appear to 
cause a fractionation of the tantalic and niobic acids. In 
this tantalite the tantalic acid is in relatively very large 
amount to the niobic acid. Judging from the colour of the 
ignited acids, it would seem that the first fraction is almost 
pure tantalic acid, the second fraction being of a slate-blue 
colour is indecisive, but the third fraction would seem to 
contain most of the niobic acid, as the white acid becomes 
of a bright yellow colour when ignited ; on cooling it 
becomes white again. This method does not free the 
metallic acids from tin, tungsten, Ac. 

Method No. 2. — Fusing Minerals with a Mixture of 
Borax and Potassium Carbonate (Wollaston). — I have not 



Tantalum, Niobium, and Titanium. 



t Chemical News, 
I Jan. I, xgog 



Time taken. KOH used. 



Hours. 



First fusion . 
Second fusion 
Third fusion 
Residue 

Total . . 



Matter left 
after treating 
with acid. 
Grras. 
2766 
0"840 
0-047 



Table I. 

Acids precipitated 

from alkaline 

solution. 

Grms. 

1-895 
1-543 
0649 
(0-047) 



Colour of acids on ignition. 



Acids remained white. 
Acids have a slate-blue colour, hot or cold. 
Acids bright yellow when hot, white on cooling. 
Yellowish white. 



18 



3-653 



4-134 grms^ = 82-68 per cent. 



tested this process, since the introduction of sodium salts into 
materials containing tantalic acid gives rise to very slightly 
soluble salts, and is consequently objectionable. The 
effect of the boric acid is uncertain, but from what is 
known of its behaviour with tungstic acid and similar 
bodies it may be supposed that it would probably form 
complex compounds, boro-tantalates, boro-niobates, &c. 
Therefore its employment in the present state of our know- 
ledge on these points does not seem advisable. 

Method No. 3. — Treating with Hydrofluoric Acid or 
Fusing ivith Potassium bi/luoride{h. Smith, W. Gibbs,and 
Marignac). — The action of hydrofluoric acid on the various 
tantalic, niobic, and titanic acid containing minerals 
appears to resemble its action on various silicates. It is 
well known that while some silicates are readily decom- 
posed by this agent, others, such as zircon, andalusite, 
staurolite, &c., are but little affected by it. Lawrence 
Smith has shown (" Original Researches," p. 353) that 
samarskite, euxenite, and hatchettolite are readily and con- 
veniently opened up by this reagent, and he points out 
that the rare earths are separated in a dense and granular 
form as insoluble fluorides, while the metallic acids go 
entirely into solution. But when he states that " there is 
no columbate which does not readily yield to this treat- 
ment," he is stating more than the facts warrant. I have 
tried this method on various columbites and tantalites, and 
have found that even when the pulverisation of the minerals 
was effected as he directs by levigation with alcohol, &c., 
the opening up of even i grm. of the mineral is a very 
tedious and lengthy operation. Some of the complex 
titano-niobates are but little attacked by hydrofluoric acid. 
Fusion with bifluoride of potassium has some advantages ; 
its action is more powerful than that of aqueous hydro- 
fluoric acid. When used in conjunction with potassium 
bisulphate it will decompose many minerals which are 
hardly attacked at all by hydrofluoric acid, such as 
cassiterite, corundum, rutile, &c. (Clark, Chemical News, 
xvi., 232). The objections to these processes are : — That 
all the first operations have to be entirely carried on in 
platinum ; the solutions, if cold and acid or neutral, can 
often be dealt with in ebonite vessels, and on a larger scale 
I have found the use of the paper-pulp utensils found in 
commerce coated with a hard resistant varnish very con- 
venient. However, neither ebonite or the other utensils 
are practicable with alkaline solutions, especially when 
these are hot. Again, while the utility of hydrofluoric 
acid and fluorides as powerful agents (which are in many 
cases indispensable) cannot be denied, they are not sub- 
stances which recommend themselves for use in the 
laboratory if they can be replaced by other bodies. Apart 
from the facts that their employment renders the ordinary 
laboratory utensils unavailable, and the deterioration of all 
glass vessels in their neighbourhood, their toxic effects are 
worthy of consideration. A long experience on a large 
scale with these bodies convinces me that the greatest care 
is necessary in their use. The incautious inhalation of 
hydrofluoric acid, spilling it on the hands and nails, and 
the internal administration of only a few milligrammes of 
the soluble bifluorides is attended with serious conse- 
quences. When minerals have been attacked by fluorine 
compounds, bases such as iron, manganese, and tin pass 
into solution with the metallic acids, and are subsequently 
removed with difficulty. This is especially the case with 



tin. Hydrofluoric acid and fluorides resemble oxalic acid 
in this respect, that they prevent the precipitation of tin by 
hydric sulphide. Hall and Smith's researches {Proc. 
American Phil. Soc, xliv., 181, 187, 190) show how tin 
kept turning up in the tantalic and niobic acids prepared 
from the double potassium fluoride salts, though their 
solutions had been treated repeatedly with hydric sulphide. 

Method No. 4. — This process for opening up tantalites, 
niobites, &c., was recommended by Ste. -Claire Deville. I 
have had no experience of it as applied to minerals. The 
extreme volume occupied by the sublimed chlorides of 
tantalum and niobium and their contamination with ferric 
chloride are mentioned by Joly. H. Rose employed com- 
bustion tubes 5 feet long and nearly an inch in diameter to 
obtain 12 to 15 grms. of the sublimed chlorides. It ap- 
pears to be more adapted for the working up of the acids 
obtained in the usual way than for minerals. It offers 
one great advantage that it separates the tin, titanium, 
germanium, and silicon in the form of very volatile com- 
pounds (zirconium will, however, be found with the tan- 
talum and niobium chlorides), and up to the present time 
this chlorine treatment appears to be the only really 
efficient process for separating titanium from tantalum and 
niobium. 

Method No. 5. — H eating the Minerals mixed zvith Carbon 
in an Electric Furnace. — Moissan reduces the minerals to 
fine powder, mixes them with charcoal from sugar inti- 
mately with the aid of a little sugar syrup, calcines the 
mixture in a Perrot-furnace, and then agglomerates the 
mass by pressure. These masses are then heated in an 
electric furnace with a current of 1000 amperes at 50 volts 
pressure for seven to eight minutes. In this way Moissan 
states that the whole of the manganese and the greater 
part of the iron and silicon are volatilised. The product 
is a brittle metallic crystalline mass, which contains all 
the tantalum and niobium combined with carbon. The 
mass reduced to powder is attacked by a mixture of hydro- 
fluoric and nitric acid, the iron is separated by ammonium 
sulphide, and the mixed tantalic, niobic, and possibly 
titanic acids are then separated by Marignac's method. 
Or alternatively he treats the fused mass broken up into 
coarse powder with dry chlorine gas at a red heat, as in 
Deville's process. Since few laboratories have at com- 
mand electrical installations capable of giving a current of 
1000 amperes at 50 volts pressure, it is obvious that this 
mode of procedure can have but a limited application. I 
have found that tantalite and columbite in small pieces 
can be fused by means of an oxyhydrogen blowpipe, using 
a block of gas retort carbon as a support, into brittle fused 
buttons. These buttons, however, were not readily 
attacked by the mixture of hydrofluoric and nitric acid, 
probably because they contain a considerable admixture 
of fused or semi-fused tantalic and niobic acids. 

Method No. 6. — Fusion ivith Bisulphates of Potassium 
{Sodium or Ammonium). — Of all the methods proposed for 
opening up these minerals, the employment of bisulphate 
(or more properly pyrosulphate) of potassium, first sug- 
gested by Berzelius, seems to be the one almost universally 
adopted, especially for tantalites and columbites. Still, 
no one who has had much experience with it will deny 
that in many respects it leaves much to be desired. The 
fumes evolved upon heating any amount of the salt are 
extremely irritating, and the operations must therefore be 



Chemical News, i 
Jan. r, 1909 I 



Tantalum, Niobium, and Titanium. 



conducted under a hood with a good draught. The 
minerals, especially in the case of tantalites, must be 
reduced to an extremely Jine powder if anything like a fair 
openingupis to be obtained. Lawrence Smith, for instance, 
speaks of i grm. of columbite requiring ten to fifteen 
minutes constant trituration in a four-inch agate mortar. 
My own experience is that even when the division of the 
mineral is carried on to an extent inconvenient in ordinary 
laboratories a complete resolution of the mineral is rarely, 
if ever, attained at one operation. However long the 
fusion is continued, the acids obtained by extracting the 
melt with hot dilute sulphuric acid always contain basic 
matters, and especially iron and zirconia ; even a second 
fusion in many cases by no means removes all these im- 
purities. One must not be misled by the white appearance 
of the acids ; they may be nearly white, and yet contain 
as much as 4 per cent of iron and other impurities. 
Adding a few drops of ammonium sulphide to the moist 
acids should not blacken them (lead or iron). The acids 
not ignited or strongly heated ought to be perfectly soluble 
in a hot solution containing their own weight of oxalic 
acid. Any insoluble matter indicates lime, lead, thoria, 
ceria, and yttria group of metals, &c. The quantity of 
saline matters introduced by the large amount of potassium 
bisulphate generally recommended is inconvenient when 
the basic matters have to be estimated, and as the 
bisulphate invariably loses a good deal of its sulphuric acid 
during the heating, there is a tendency to form in some 
cases extremely insoluble double sulphates, such as 
zirconium-potassium sulphate, which is, according to 
Fresenius, almost absolutely insoluble in water, and in 
hydrochloric acid if precipitated hot. Again, it has been 
shown, especially by Prior {Mineralogical Mag., xv., 83), 
that when much titanic acid is present along with tantalic 
and niobic acids, " on fusion with acid sulphate of 
potassium and treatment of the melt with a 5 per cent 
solution of sulphuric acid, practically the whole passed into 
solution." I can quite confirm this statement from my 
own experience ; it has long been known that this method, 
recommended in most text-books as a means of separating 
titanic acid from tantalic and niobic acids, was imperfect, 
but Mr. Prior has demonstrated that in the presence of 
large amounts of titanic acid it is absolutely untrustworthy 
and misleading, and consequently the published analyses 
of minerals containing these three acids require in some 
cases considerable corrections. These minerals contain 
very frequently as constituents other metals, such as tin, 
tungsten, lead, antimony, and germanium, and when 
such minerals are treated with alkali bisulphates, the tin 
and tungsten certainly, and the antimony and germanium 
probably, become so firmly united to the tantalic-niobic 
acids that their separation becomes a mattei of extreme 
difficulty. Berzelius recommended that the washed 
tantalic-niobic acids should be digested with ammonium 
sulphide to lemove the tin, tungsten, &c. Rose (" Chimie 
Analytique Quantitative," 1862, p. 456) found that this 
plan did not answer, and he recommended fusing the acids 
with six times their own weight (!) of a mixture of equal 
parts of dry sodium carbonate and sulphur. Why such an 
enormous excess of alkaline sulphide is used is not 
apparent. Rose states, however, that this fusion converts 
a good deal of the acids into insoluble sodium tantalates 
and niobates, and consequently the whole must be again 
fused with six times its weight of potassium bisulphate and 
treated with hot dilute sulphuric acid as before to free 
them from the combined soda. Rose says naively : " Ce 
traitement est un peu complique," but one fears that those 
chemists who have tried it would use stronger terms before 
they finished the operations. Dr. Edgar Smith says on 
this point: — "Our own experience leads us to say that 
the removal of tungsten and tin from columbium and 
tantalum oxides cannot be realised by digestion with 
ammonium sulphide. Indeed, not only did we find the 
fusion with the sodium carbonate and sulphur necessary, 
but that working on large quantities of material, as in our 
case, two or even three refusions with these reagents were 



found necessary " {Proc. Am. Phil, fioc, xliv., 157). 
Blomstrand also (yourn. Prakt. Chem., xcix., 40) did 
not obtain favourable results with this method. He points 
out that if a low temperature is applied in the fusion the 
tin, tungsten, &c., are not removed, while if a higher heat 
is employed the tantalic and niobic acids pass into solution 
along with the tin and tungsten sulphides when the melt is 
treated with water. It is therefore apparent that the 
complete removal of the tin, tungsten (and probably also 
of antimony and any germanium) is an exceedingly tedious 
operation when carried out in this manner. It seems to 
be commonly assumed that the residue left on treating 
with water or dilute sulphuric, the result of a fusion of a 
tantalate or niobate with potassium bisulphate, is tantalic 
or niobic acid mixed with a certain amount of basic 
matters. But, as a matter of fact, this residue is really a 
tantalic or niobic sulphate (Moissan, "Chimie Minerale," 
ii., 139). Hermann {yotirn. Prakt. Chem., 1872, '2), v., 
66) found in the product obtained by fusing tantalic acid 
with potassium bisulphate, exhausting the melt with boiling 
water, and drying at 100'' C, 85*25 per cent of tantalic 
acid, 523 per cent of SO3, and 9-52 per cent of 
water, corresponding fairly well with the formula 
3(Ta205),S03,9H20. Rose points out that the acids can 
be washed continuously for several weeks without 
eliminating all the sulphuric acid. When the washed 
sulphides are collected on paper filters one observes that 
the paper becomes quite rotten, and even charred when 
dried at 100^ C, from the liberation of sulphuric acid. 
It has been recommended that the acids should be washed 
with dilute ammonia in order to get rid of the sulphuric 
acid. I have tried this on the acids obtained from 
columbite by fusion with sodium pyrosulphate. After the 
acids had been well washed with dilute sulphuric acid and 
then with water only, they were stirred up with a slight 
excess of ammonia. This caused a great change in their 
appearance ; at the beginning they were pulverulent, but 
the treatment with ammonia converted them into a 
flocculent state. Yet in this condition they filtered bright 
and fairly well. But iht clear filtrate contained a surprising 
amount of the acids, which came down when the ammonia 
was just over-neutralised with hydrochloric acid. The 
precipitate was filtered off and washed. On examination 
it gave a very strong reaction for niobic acid with zinc 
dust, but only a very faint indication of titanic acid with 
peroxide of hydrogen ; ,it was not examined for tantalic 
acid. It is clear that the acids (or rather the sulphates) 
are distinctly soluble in ammoniacal ammonium sulphate, 
and as this mode of procedure has been recommended in 
the quantitative analysis of the acids, a word of caution 
as to the error it involves is not out of place. It is 
not improbable that when the moist crude acids 
are treated with sulphide of ammonium in order 
to extract the tin, tungsten, iron, &c., that a 
certain amount of niobic and, perhaps, tantalic acid 
will be found to go into solution along with the tin and 
tungsten sulphides, as ammonium sulphate must be formed 
in this case also. I intend when time permits to follow up 
this question of the solubility of the acids in ammoniacal 
ammonium sulphate ; possibly only niobic acid may thus 
be dissolved and not titanic or tantalic acid. The use of 
sodium pyrosulphate instead of the potassium salt seems 
advisable on the ground that it is far more soluble, and 
when rare earths are present it has not so much tendency 
to form insoluble double sulphates. It appears to me, 
however, to lose sulphuric acid at a lower temperature 
than the potassium salt. I have tried on some occasions 
ammonium bisulphate as recommended by Rose. I found 
that finely ground columbite can be opened up with this 
reagent, heating in Jena glass beakers, but tantalite seems 
but little attacked. I have never, however, been able to 
completely dissolve columbite in the fused salt so as to get 
a clear glassy mass which would dissolve in water tem- 
porarily to a clear fluid in the manner spoken of by Rose. 
There was always a residue which the most prolonged 
heating failed to dissolve. Vessels of fused silica are very 



Formation of Nitrides of Barium &c. 



I Chemical News, 
\ Jan. I, 1909 



useful for these fusions with bisulphates, and are to be 
preferred to platinum, which metal is not unaffected by 
long heating with acid sulphates. Solutions of titanic 
hydrate in nitric and sulphuric acid seriously attack both 
platinum and platinum-iridium basins when they are 
evaporated in them. This is alluded to by Rose {Chimie 
Analytique Qualitative, p. 1028), but appears to have 
keen overlooked since his time, as Fresenius recommends 
platinum dishes for the estimation of titanic acid in acid 
solutions ("Quantitative Analysis," p. 196). I have found 
that when pure titanic acid is fused with potassium or 
sodium carbonate, the melt dissolved in nitric acid, and 
the whole evaporated to dryness on the water-bath in 
platinum, on taking up with water and dilute nitric acid 
the insoluble titanic acid is quite grey in colour and the 
dish has lost in weight considerably. According to Rose, 
tantalic and niobic acids do not act in this way on 
platinum. I hrst noticed this action of titanic acid solu- 
tions on platinum in attempting to separate a mixture of a 
quantity of rare earth oxides from a considerable amount 
of titanic acid with which they were mixed, by dissolving 
in nitric acid and evaporating to dryness on the water-bath 
in a platinum basin, as one would proceed for the estimation 
of silica. 

Requiring some quantities of pure tantalic, niobic, and 
titanic acids for various experiments, I was led to think 
whether it would not be possible to devise some better way 
of extracting these bodies from their native compounds, 
and especially from ordinary columbites and tantalites, so 
that as far as possible the use of fluorine compounds and 
the employment of platinum vessels should be avoided, 
and also that the very tedious means hitherto made use of 
for the separation of tin, antimony, iron, and other im- 
purities could be improved. As my efforts in these 
directions have not proved unsuccessful, I offer the results 
of them to our readers. Desiring to obtain some materials 
uniform in composition so that experiments could be 
repeated under like conditions, I obtained some time ago 
parcels of minerals in some quantity. One of these was 
columbite ; this I obtained from a dealer who had had it in 
stock for many years. It was marked " Columbite from 
Middleton, Connecticut, U.S.A." The weight of this was 
about 10 kilogrms. It was externally very free from 
foreign matters, and many of the lumps were highly 
crystalline and beautifully iridescent. Another material 
was massive tantalite, partly from Greenbushes, West 
Australia, and partly from the Northern Territories, 
Australia. These were also fairly free from foreign 
admixtures ; the exterior of some of the pieces, however, 
was covered with a thin drab-coloured adherent coating 
which could not be wholly removed by washing, and as it 
contained tantalic acid it appeared to consist of what is 
known as tantalic ochre. The weight of these tantalites 
was about 30 kilogrms. 

(To be continued). , 



LECTURE EXPERIMENTS SHOWING THE 

FORMATION OF THE NITRIDES OF BARIUM, 

STRONTIUM, CALCIUM, AND ALUMINIUM. 

Ry H. RUSSELL F.LI.IS, B.Sc, F.C.S. 

If a mixture of the oxide of one of the above metals and 
magnesium powder is spread over an iron sand-tray, 
and ignited by means of a match or a piece of burning 
magnesium, a reaction takes place similar to Goldschmidt's 
thermite reactions. The reaction is intense, but is not 
violent, no violent evolution of the products of the reaction 
occurring. 
The mixtures were made : — 



1. BaO + Mg. 

2. BaO + 2Mg. 

3. SrO + Mg. 

4. SrO + ^Mg 



5. CaO-l-Mg. 

6. CaO|2Mg. 

7. Al303-^3Mg. 



The magnesium powder replaces the other metals owing 
to the heat of combustion of magnesium being greater 
than that of barium, calcium, strontium, and aluminium 
(see Trans. Far. Soc, iv., Part II., p. 130). 

In order to commence this reaction, a high initial tem- 
perature is necessary, and this is supplied by the burning 
magnesium. 

The free metal, as soon as it is produced, being in 
contact with air, immediately combines with oxygen and 
nitrogen. 

With BaO, CaO, and SrO the product was quite yellow, 
and on moistening with water smelt very strongly of 
ammonia ; wih AI2O3 the product was black, but also 
smelt strongly of ammonia on adding water. 

In the experiments with the oxides of the alkaline earths, 
carbonate, hydrate, and peroxide must be absent ; if these 
are present the action is violent, and the formation of 
nitride is much decreased. 

Calcium oxide, if the carbonate is present, gives no 
nitride, carbide, nor cyanide ; barium and strontium oxides 
containing appreciable quantities of carbonates yield 
nitride, cyanide, carbide, and, possibly, cyanamide. 

Excess of magnesium powder, as a rule, produces a 
larger yield of the nitride, possibly by union with the 
oxygen of the air leaving the nitrogen for the other metal. 

Estimations of the amount of nitrogen gave the 
following : — 

Maximum yield. 

1. BaO-f-Mg Per cent of BasNs = 24-4 78-4 

2. BaO-|-2Mg „ „ = 43-33 64-5 

3. SrO-fMg „ Sr3N2 = 33-69 70-6 

4. SrO-f2Mg „ „ = 5384 54-6 

5. CaO-l-Mg „ CajNa = 33-65 55 

6. CaO-|-2Mg „ „ = 31-55 37-9 

7. Al203-t-3Mg „ Al.N = ir-145 40-9 

In the last column under the heading maximum yield is 
given the percentage of nitride that would be produced if the 
whole of the metal from the oxide became converted into 
the nitride, ^.o^., 3CaO-f 6Mg-^30-|-2N = Ca3N2 + 6MgO. 

The free metal after the reaction was always very small, 
never amounting to more than 3 per cent. 

That the nitride does not consist of magnesium nitride is 
evident from the following considerations . — 

When magnesium burns in air, either as the powder or 
the ribbon, less than i per cent of nitride is obtained, and 
when an oxide is reduced, the metal of which does not form 
a nitride, the yield of nitride is again less than i per cent. 

Magnesium nitride readily burns, and if a great heat 
evolution takes place the nitride would burn ; now, when 
Mg reduces CaO the heat evolution is not excessive — 

Mg-t-CaO = MgO + Ca-|-3ooo cals. 

145,000 148,000 

with such a reaction, as a large evolution of heat occurs : — 

CaO-fMg = MgO+Cu-f iii,ooocals. 

37,000 148,000 

In the first case we might expect that any magne.sium 
converted into the nitride would remain as such, but from 
the study of two other reactions in which a similar small 
heat evolution occurs, no nitride is produced. The two 
reactions in question are : — 

I. B205 + 3Mg = B2-f3MgO-|-io8,ooo. 

316,000 444,000 

(For one molecule of MgO 36,000 cals. being liberated). 

2. Si02 + 2Mg = 2MgO-(-Si-(-40,iio. 
2 1 5, 690 296,000 

(For every molecule of MgO 20,000 cals. being liberated). 

Again, using excess of magnesium, although the yield of 
nitride is increased, the amount produced is never above 
that which could be produced from the metal obtained 
from the oxide. The above experiments are being repeated 
in vacuo, and in an atmosphere of nitrogen. 

The Chemical Laboratory, 
The Polytechnic, Kcgent Street, W. 



Chemical News, 1 
Jan. I, 1909 I 



Combustion Analysis, 



COMBUSTION ANALYSIS.* 

By JAMES WALKER, F.R.S., and THOMAS BLACKADDER, 
B.Sc, University College, Dundee. 



The process of Dennstedt for the elementary analysis of 
organic compounds by combustion in oxygen with the help 
of platinised quartz was tried in this laboratory, and in 
expert hands was found to be both rapid and accurate. 
The average Situdent, however, experienced great difficulty 
in the conduct of the combustion, and it occurred to us 
that the advantages of the apparatus of Dennstedt, so 
carefully worked out by him in detail, might be applied 
to the ordinary method of combustion by means of copper 
oxide. 

If one inspects a tube in which a copper oxide com- 
bustion is being conducted, it is found that the oxide 
actually reduced to metallic copper after the combustion 
of the volatile matter is completed, rarely extends for 
more than an inch or two along the tube, unless the 
process has been accidentally " rushed." It seemed, 
therefore, possible to reduce the dimensions of the com- 
bustion-tube to such an extent as to secure the advantage 
of the Dennstedt furnace, which from its lightness of con- 
struction admits of rapid heating and cooling. This we 
discovered to be the case, and in reality there is no greater 



while still hot to a tube A, Fig. 2, which is then closed 
with a stopper, through which passes a calcium chloride 
tube to protect the copper oxide from atmospheric moisture. 
If the substance to be analysed is a solid, it is weighed off 
in a small stoppered bottle b, Fig. 2, the neck of which 
fits into the constriction of a, so that the substance may 
be mixed in b with a quantity of copper oxide from a, with 
as little exposure to the atmosphere as possible. The end 
of the combustion-tube fits into the wider part of A, so 
that it also may be conveniently charged with copper oxide 
from the ignited supply. After the combustion - tube 
has received its charge of copper oxide, the mixture of 
substance and copper oxide is transferred from r. into the 
combustion-tube, the neck of the stoppered bottle being 
of such a diameter as to fit inside the end of the latter. 
The bottle is then "washed out" once or twice with 
copper oxide, received as before from a, and emptied into 
the combustion-tube. The absorption-tubes and oxygen 
supply are next attached and the combustion begun. The 
two burners at the front (absorption end) of the tube are 
lit and tiles are placed over them, the heat being as far as 
possible confined to the portion of the tube covered by the 
tiles by means of screens of asbestos paper. When the 
copper oxide has attained dull redness, the third Bunsen 
is lit at the other extremity of the tube without a tile. The 
heat from this Bunsen gradually volatilises the substance, 




difficulty in performing a copper oxide combustion in a 
shortened Dennstedt furnace, heated by three Bunsen 
burners, than in a furnace of the customary type heated 
by thirty. The saving of initial outlay on the furnace, 
and on the current consumption of gas is, of course, com- 
paratively great, but a still more considerable advantage 
is that the combustion may be done on the worker's bench 
without inconvenience to himself or to his neighbours. 

The furnace employed by us, together with the burners, 
absorption-tubes, and the purifying apparatus for the 
supply of oxygen, are practically all as described by 
Dennstedt, and shown to scale in Fig. i. The chief 
modification is that the furnace is cut down to 60 cm. in 
length. The combustion-tube is of Jena glass, 66 cm. 
long, and need not be more than 8 mm. internal diameter. 
The total volume of such a tube is only about 30 cc, and 
the charge of copper oxide, including spirals, weighs only 
35 grms. Two of the burners are supplied with attach- 
ments for spreading the flame into a flat sheet ; the third 
is used for local heating, but towards the end of the com- 
bustion, when the whole tube is heated, it also may be 
provided with a flame-spreader. 

The copper oxide employed is coarsely powdered and 
sifted free from fine dust, which during the combustion 
might clog and stop the tube. The combustion is carried 
out in a current of oxygen, and the calcium chloride and 
soda lime absorption-tubes are always weighed filled with 
the same gas. 

The method adopted for mixing the substance with 
copper oxide, and transferring it to the combustion-tube, 
is a slight modification of that used by Professor Thiele, 
of Munich. The copper oxide after ignition is transferred 

♦ From the Procttdings of the Royal Society of Edinburgh, xxviii., 
Part ix., No. 44. We are indebted to the Royal Society of Edinburgh 
for the blocks illustrating this Paper. 



adZ) 



DC 



3 



Fig. 2. 

with or without decomposition, the volatile products being 
for the most part burned in the moderately rapid stream of 
oxygen (two to three bubbles per second) which is all the 
time passing through the apparatus. The Bunsen is 
gradually moved forward as the combustion proceeds, tiles 
being placed behind it to keep the tube still hot. Under 
ordinary conditions there is no visible reduction of copper 
oxide to metallic copper, although towards the end of the 
combustion the oxide usually glows immediately behind 
the tiles at the absorption end of the tube. To burn any 
carbon that may be left on the tube by decomposition, all 
the tiles are placed in position, and the three burners ad- 
justed so that the tube is heated as uniformly as possible 
to dull redness. The carbon at this temperature is not 
graphitised and burns off readily. When the oxygen 
comes freely through the indicator bottle at the end of the 
apparatus, the combustion is finished, and very little 
sweeping out is necessary, owing to the small volume of 
the apparatus. Immediately after the combustion, the 
copper oxide is returned to the tube a, and is ready for the 
next analysis. 

The time occupied between attaching and removing the 
absorption-tubes need not exceed half an hour. The 



Determination of Halogens in Organic Compounds. 



I Chemical News, 
< Jan. I, 1909 



amount of oxygen consumed in a combustion averages 
800 CO. 

In order that an idea may be formed of the rapidity and 
accuracy of the method, the following results may be 
quoted. Four combustions of succinic acid were per- 
formed, including weighing, between 9 a.m. and i p.m., 
two sets of absorption-tubes being used, in order that no 
time might be lost in waiting for the tubes to cool before 
weighing. 

Quantity taken. Percentage carbon. Percentage hydrogen. 

o-i866 grm. 40'6i 5-28 

0-1492 „ 40-44 5-20 

0-1890 „ 40-48 5-18 

0-1733 „ 40"56 5'20 

(The theoretical percentages for C4H60., are carbon =40-68, 
hydrogen = 5-09). 

If the substance contains nitrogen, a metallic copper 
spiral 7 cm. long is, as usual, placed at the front of the 
tube, and the current of oxygen is passed at a slower rate 
at the beginning of the combustion. For acetanilide the 
following percentages were obtained: — Carbon, 71-03, 
71-24; hydrogen, 6-72, 6-89, the numbers for the formula 
CsHgNO being 71-11 and 6-67 respectively. 

When the substance is a liquid it is weighed off in a 
small bulb with a sealed capillary, the tip of the capillary 
being broken off before its introduction into the tube. The 
best results are got when the capillary is comparatively 
wide and about 8 cm. long. The open end of the capillary, 
surrounded by the copper oxide, faces the stream of oxygen. 
The liquid, when the copper oxide in the front of the tube 
has reached dull redness, is slowly distilled out of the bulb 
into the copper oxide at the cool end of the tube by means 
of a small Bunsen flame applied directly to the upper side 
of the tube over the bulb. The combustion is then con- 
tinued as for a solid. 

When a volatile liquid, such as benzene, is burned, it is 
introduced into the tube in a small sealed bulb terminating 
in a capillary at either end. The longer capillary (8 cm.) 
is plugged with fusible metal (compare Hempel, " Gas 
Analysis,'" p. 341), and the shorter (3 cm.) is sealed off in 
the flame after the bulb has received its charge of benzene. 
In this case it is advisable not to surround the bulb and 
capillaries with copper oxide, but to leave the whole clear 
at the back of the tube. The little plug of fusible metal at 
the end facing the current of oxygen is melted by the 
application of the flame above the combustion-tube, and 
the benzene is gradually vaporised by very gentle heating. 
The following result was obtained by this method : — 

Carbon =91-94 per cent; hydrogen =^ 7-83 per cent. 
Calculated for CeHe — Carbon = 92-31 per cent; 
hydrogen = 7-69 per cent. 

A combustion-tube of the same dimensions may be used 
for estimating nitrogen by the direct method. In this case 
a current of carbon dioxide is substituted for the current of 
oxygen, the nitrogen being collected over concentrated 
potash solution. The reduced copper spiral necessary in 
this case need not exceed 7 cm. in length. The per- 
centage of nitrogen in aniline found by this method was 
in two experiments 15-09 and i5"25, the percentage re- 
quired for the formula C6H7N being 15 05. Equally 
satisfactory results were obtained with acetanilide and 
hippuric acid. 

To show that the method gives satisfactory results in 
the hands of a beginner, the following consecutive analyses 
may be quoted from the notebook of a student who had no 
previous experience of organic combustions : — 

Carbon. Hydrogen. 

Succinic acid. Found I. 39'9i 5"i9 

„ II. 40-54 5-20 

Calculated 40-68 5-09 

Cane sugar. Found 1. 4083 6-48 

„ II. 41-81 663 

„ III. 42-12 6-41 

Calculated 42-11 6-43 



It is apparent, then, that the method as here described 
is well adapted to ordinary laboratory work, and compares 
very favourably with the copper oxide method as usually 
employed in respect of economy in apparatus, gas, and 
time, and of the greatly increased comfort of the operator. 



ON THE DETERMINATION OF HALOGENS IN 

ORGANIC COMPOUNDS.* 

By C. W. BACON. 

I. Introductory. 
H.\LOGENS are at present determined in organic com- 
pounds almost exclusively by the method of Carius. While 
generally reliable, the method is quite laborious. First, it 
requires some hours of actual work, including as it does 
a gravimetric determination of silver halide. Besides, 
eight or nine hours heating with fuming nitric acid in- 
volves a delay in getting the final result, which is at times 
extremely inconvenient. 

About two years ago Stepanoff {Ber., 1906, xxxix., 405) 
published a method for the quantitative determination of 
halogens in organic compounds based on the reducing 
action of nascent hydrogen. He dissolves a weighed 
amount of the halogen compound in 20 to 40 cubic centi- 
metres of 98 per cent alcohol in an Erlenmeyer flask con- 
nected with a reflux condenser, places the flask on a water- 
bath, and adds gradually through the condenser twenty-five 
times the amount of sodium corresponding to the reaction 
R.Hlg 4 C2H5.0H + 2Na = Na.Hlg + CzHj.ONa + R.H. 
When the reaction is over he adds 20 to 40 cubic centi- 
metres of water, distils off the alcohol, acidifies strongly 
with nitric acid, and determines the halogen in the resulting 
solution by Volhard's method. 

Stepanoff's method was tried in these Laboratories, 
exactly as described by the author, in connection with a 
study of the esterification of some refractory aromatic 
acids containing halogens. The results, however, were 
entirely unsatisfactory. The figures yielded by consecu- 
tive analyses of one and the same substance differed greatly 
from one another, and were many per cent removed from 
the truth. 

At the request of Professor Rosanoff I then undertook 
to reinvestigate the subject with a view to ascertaining 
under what conditions, if at all, nascent hydrogen can 
really be relied upon to reduce organic halogens quan- 
titatively. The analytical conditions and procedure recom- 
mended below are the result of a large number of painstaking 
trials. If the simple directions are followed, success may 
be confidently expected in every case. A single determi- 
nation requires about two hours ; but if three or four 
determinations are carried on simultaneously a considerable 
number of analyses can be conveniently performed in the 
course of a working day. 

2. Analytical Directions. 

Introduce about 0-2 grm. of the halogen compound into 
a dry pear-shaped (Kjeldahl) flask. 

If w is the number of grms. of the compound taken, add 
156W cubic centimetres of alcohol (at least 98 per cent) if 
the compound contains chlorine, or 6?>zti cubic centimetres 
if the compound contains bromine, or 44W cubic centimetres 
if the compound contains iodine. Connect the flask with 
a reflux condenser, clamp it over a square of wire gauze 
covered with a thin sheet of asbestos, and warm with a 
Bunsen burner until the substance is dissolved. 

Introduce very gradually, through the condenser, a total 
of 19-5W grms. of sodium if the compound contains chlorine, 
or 8-5?^' grms. of sodium if the compound contains bromine, 
or 5-5^ grms. of sodium if the compound contains iodine. 
(These quantities represent about fifteen times the amount 

♦ Contributions from the Chemical Laboratories of Clark University. 



Chemical News, ) 
Jan. I, igog ' 



Cobalti-nitrite Method of Estimating Potassium in Soils. 



of sodium corresponding to the chemical equation given in 
the preceding section, assuming the substance analysed to 
contain loo per cent halogen). This operation should be 
extended over at least thirty minutes. Toward the end of 
the operation maintain the solution at the boiling-point by 
means of a Bunsen burner, and when the introduction of 
the sodium is complete boil the solution gently for one 
hour longer. 

Then allow the temperature of the solution to fall to 
about 50° or 60°, dilute freely, through the condenser, with 
cold water, acidify with nitric acid, add a moderate excess 
of silver nitrate, and on complete cooling determine the 
excess of silver titrimetrically by Volhard's method. If 
the halogen involved is chlorine, filter out the precipitated 
silver halide before titrating with sulphocyanate. If the 
halogen is bromine or iodine, filtration is unnecessary (see 
Rosanoff and Hill, Jonrn. Am. Chem. Soc, 1907, xxix., 
269 ; Chemical News, xcvi., 299). 

A few additional remarks may not be surperfluous. The 
statement that the liquid should be boiled for an hour after 
the solution of the sodium is complete may seem sur- 
prising ; for sodium ethylate is believed by some to have 
no action upon haJogen compounds of the aromatic series. 
While the additional boiling is probably unnecessary in the 
case of aliphatic compounds, the following experiment will 
show that the operation is not useless in the case of re- 
fractory aromatic compounds. An alcoholic solution of 
hexachloro-benzene was boiled for one hour with the 
amount of sodium ethylate required by the above directions. 
The solution, diluted with water and acidified, was found 
to contain no less than 25 per cent of the amount of sodium 
chloride corresponding to the hexachloro-benzene used. 
While in similar experiments I was unable to transform 
monobromo-benzene into phenetol, there is no doubt but 
that the alcoholates of sodium attack halogens in a benzene 
ring quite vigorously. In fact, if the action were not some- 
what too slow for analytical purposes, it might be employed, 
independently of any other method, for the quantitative 
estimation of halogens in organic compounds. 

Special experiments showed that distilling off the alcohol 
(as Stepanoff does) before titrating with sulphocyanate is 
unnecessary. In the solution copiously diluted with water 
the alcohol has no effect upon the end-point. 

Finally, Kahlbaum's sodium was found to be sufficiently 
pure for use in connection with the method here proposed. 

3. Some Test Results. 
The following results were obtained by the method 
proposed : — 

1. A sample of 1-2 4-6 irichlorobenzoic acid prepared in 

this laboratory was found to contain 4729 per cent 
of chlorine. The amount corresponding to the 
formula C7H3O2CI3 is 4719 per cent. 

2. Two samples of ethyl 1-2-4-6-tribromobenzoate, con- 

taining theoretically 61-99 P^'' cent oi bromine, gave 
6i'32 per cent and 61-25 P^^ cent respectively. The 
substance was probably not quite dry, but the agree- 
ment of the two results is satisfactory. 

3. A sample of pure benzene hexachloride was found to 

contain 73*23 per cent of chlorine. The theoretical 
percentage for CeHeClc is 73'i5- 

4. Ten consecutive analyses of carefully dried hexachloro- 

benzene (Kahlbaum's), with theoretically 74-71 per 
cent chloiine, i^ave the following results : — 



of chlorine found. 


Error. 


7478 


-f007 


7471 


— 


74-78 


+ 0-07 


74-76 


+ 005 


74-62 


- 009 


74-64 


-0-07 


74-69 


- ().i 


74-78 


+ 007 


7471 


— 


7475 


-fo-04 



Taking into account the fact that the four substances 
used are among the most stable organic halogen com- 
pounds, these results may be considered as sufficient proof 
of the general applicability and accuracy of the method. 

The investigation was carried out under the guidance of 
the Director of these Laboratories, Professor M.'A, 
Rosanoff, whom the writer wishes to thank again for 
his friendly interest and assistance in the work. Acknow- 
ledgment is also due to Dr. W. L. Prager for his assistance 
in the early part of the work. 

Clark I'niversity, Worcester, Mass., 
June, 1908. 



THE APPLICATION OF THE COBALTI-NITRITE 

METHOD TO THE ESTIMATION OF 

POTASSIUM IN SOILS. 

By W. A. DRUSHEL. 

In a previous paper from the Kent Chemical Laboratory of 
Yale University it was shown that potassium may be esti- 
mated with a fair degree of accuracy by precipitating it as 
potassium sodium cobalti-nitrite in a solution acidified 
with acetic acid and oxidising the precipitate with standard 
potassium permanganate (Am. Journ. Sci.. 1907, xxiv.. 
433; Chemical News, xcvii., 124). In the same paper 
the applicability of the method to the estimation of potas- 
sium in commercial fertilisers was shown by a series of 
experiments. 

In the method as previously worked out an excess of 
concentrated sodium cobalti-nitrite solution acidified with 
acetic acid is added to a neutral solution of a potassium 
salt, and the mixture is evaporated to a pasty condition on 
the steam-bath. After cooling, the residue is stirred up 
with sufficient cold water to dissolve the excess of 
sodium cobalti-nitrite. The precipitate, consisting of 
K2NaCo(N02)6.H20, is filtered on a rather close asbestos 
felt in a perforated crucible and well washed with cold 
water, or preferably with a half saturated sodium chloride 
solution. The precipitate and felt are transferred to an 
excess of standard N/io or N/5 potassium permanganate 
which has been diluted to about ten times its volume and 
heated nearly to boiling. If particles of the precipitate 
stick persistently to the walls of the crucible and cannot 
be removed with a spray of water, the crucible is put into 
the permanganate solution. After stirring for a few 
minutes the solution is gradually acidified with 5 cc. to 
20 cc. of dilute sulphuric acid, and the oxidation is allowed 
to go to completion, a process which seldom requires more 
than five miriutes. If no particles of the yellow precipitate 
settle out on standing a minute, the oxidation may be 
considered complete. The hot solution is then bleached 
by running in a measured amount of standard oxalic acid, 
containing 50 cc. of concentrated sulphuric acid per litre. 
The solution after bleaching is titrated to colour with 
standard permanganate in the usual manner. 

In this process the cobalt in the molecule is reduced 
from the trivalent to the bivalent condition and not re-oxi- 
dised, consequently from the molecule of the potassium 
sodium cobalti-nitrite we find 0000857 gf "'• K2O equivalent 
to I cc. of strictly Nio potassium permanganate. This 
factor, of course, must be corrected for any variation in 
the normality of the permanganate solution used. 

For the extraction of the alkalis 10 grms. of dry soil 
are placed in an Erlenmeyer flask with 25 cc. to 35 cc. of 
about 20 per cent hydrochloric acid. The flask is 
thoroughly shaken and a small funnel is hung in its neck 
to avoid too great a loss of acid by evaporation. The 
conitnts of the flask are digested on the steam-bath for 
twenty-four hours. 

From this point several methods for the final preparation 
of the sample were tried with satisfactory results, given in 
the table. Since duplicate estimations were to be made 
by the gravimetric chlorplatinate method, for which it was 



8 



Corrosion of Iron. 



I Chemical News, 
I Jan. I, igog 



necessary to remove the iron, aluminium, calcium, mag- 
nesium, phosphoric acid, and ammonium salts, if present, 
from the soil extract, the following general procedure was 
found to be most expeditious. The soil extract was 
filtered through paper into an evaporating dish and the 
residue was washed with boiling water until the filtrate 
gave no reaction for chlorine with silver nitrate. The 
filtrate was evaporated almost to dryness to remove the 
excess of hydrochloric acid as far as possible. The residue 
was dissolved in about 200 cc. of water, and after heating 
to boiling, a little ammonium hydroxide and ammonium 
oxalate were added. The mixture was boiled a minute, 
settled, filtered, and the precipitate was washed with hot 
water until a drop of the filtrate gave no chlorine reaction. 
The filtrate was concentrated, transferred to a 200 cc. 
flask, cooled, and made up to the mark. After thoroughly 
shaking, 50 cc. aliquots were pipetted off for the gravi- 
metric and volumetric estimations. The aliquots were 
evaporated to dryness in platinum dishes, and gently 
ignited to remove the ammonium chloride. After cooling, 
the residue was moistened with dilute sulphuric acid and 
again ignited, gently at first and finally at the full heat of 
the Bunsen flame, to remove the last trace of ammonium 
present as the sulphate, and to destroy any organic matter 
which might be present. 

The residue for the gravimetric estimation was dissolved 
in a little water and a few drops of hydrochloric acid over 
the steam-bath, and the estimation of the potassium was 
made according to the modified Lindo-Gladding method. 

To dissolve the residues for the volumetric estimations a 
little water and a few drops of acetic acid instead of hydro- 
chloric acid were used. In the volumetric work approxi- 
mately N/5 potassium permanganate was used, 26-08 cc. 
of permanganate being equivalent to 50 cc. of exactly 
N, 10 oxalic acid. From this ratio the factor for K2O was 
found to be 0-001642. In each case the potassium was 
precipitated as the cobalti-nitrite by evaporating off with 
10 cc. of sodium cobalti-nitrite prepared according to the 
method of Adie and. Wood (yoiirit. Client. Soc, Ixxvii., 
1076). 



No. 


Character 
of soil. 




Method. 


Soil 
taken. 
Grms. 


K.^O f( 
Grm. 


jiind. 
Per cent 


I. 


Clay . . 


(2) 
(3) 


Vol. 
Grav, 


2-5 
2-5 
2-5 


0-0028 
0-0035 
0-0035 


o-ii 
0-14 
0-14 


II. 


Clay . . 


(0 
(2) 
(3) 


Vol. 
Grav. 


2-5 

2-5 
25 


O-OIOO 

0-0092 
0-0093 


0-39 
0-37 

0-37 


III. 


Loam . . 


(I) 
(2) 
(3) 


Vol. 
Grav. 


2-5 
2-5 
2-5 


0-0074 
0-0068 
0-0075 


0-30 
0-27 
0-30 


IV. 


Loam . . 


(I) 
(2) 
(3) 


Vol. 

)) 

Grav. 


2-5 

2-5 
2-5 


0-0060 
0-0058 
0-0058 


0-24 
0-23 
0-23 


V 


Gravel . . 


(I) 
(2) 


Vol. 
Grav. 


2-5 
2-5 


0-0042 
0-0045 


0-17 
0-18 


VI 


Gravel . . 


(I) 
(2) 
(3) 


Vol. 
Grav. 


25 
25 

2-5 


0-0047 
0-0044 
00050 


o-ig 
0-18 
0-20 


VII. 


Clay . . 
Gravel . . 


(I) 

(2) 

(3) 
(4) 

(5) 


Vol. 

Grav. 

Vol. 

It 


25 
25 

2-5 

25 
2-5 


0-0048 
0-0046 
0-0045 
0-6040 
0-0044 


o-ig 
o-i8 
o-i8 
o'i6 
o-i8 



The following exceptions are to be noted to the genera 
method previously outlined for the preparation of the 
sample. In I., the excess of hydrochloric acid, the iron, 
aluminium, and calcium were removed from the separate 
portions after aliquoting, and in (i) and (2) sodiuin car- 
bonate was used instead of ammonium hydroxide and 
ammonium oxalate for the removal of the iron, aluminium, 
and calcium. In V. (i) and (2) bases other than the alkalis 



were removed in the separate aliquots by ammonium 
hydroxide and ammonium oxalate. In VII. the aliquots 
were made directly from the hydrochloric acid extract. 
That of VII. (2) was treated in the usual manner for the 
gravimetric estimation of potassium. The other aliquots 
of VII. were evaporated to dryness and gently ignited to 
remove any ammonium chloride present and to char the 
organic matter. The residues were extracted with hot 
water and a little acetic acid, filtered, and evaporated with 
sodium cobalti-nitrite in the usual manner. 

In this work the results are based on a small amount of 
soil (2 5 grms.) in each case because but a limited amount 
of each sample was available. A higher degree of 
accuracy may be secured by using 10 grms. of soil for 
each estimation instead of 2-5 gims. 

Summary. 
A weighed amount of dry soil is extracted with an excess 
of hydrochloric acid over the steam-bath. The excess of 
acid is removed from the extract by evaporation. The 
bases which might interfere with the process are removed 
with sodium carbonate or ammonium hydroxide and am- 
monium oxalate. Ammonium salts and organic matter 
are removed by ignition. The residue is dissolved in a 
little water and a few drops of acetic acid, and the mixture 
evaporated with an excess of sodium cobalti-nitrite to a 
pasty condition, stirred up with cold water, and filtered 
upon asbestos in a perforated crucible. The precipitated 
potassium sodium cobalti-nitrite is washed with half- 
saturated solution of chloride, and treated with an excess 
of permanganate in hot dilute solution. The colour of the 
permanganate is destroyed by an excess of standard acidu- 
lated oxalic acid, and the excess of oxalic acid titrated to 
colour with permanganate. — American jfonriial of Science, 
xxvi., 329. 



THE CORROSION OF IRON.* 

By ALLRRTON S. CUSHM.^N, 
Assistant Director, Office of Public Roads, Dept. of Agricnltiire, U.S. A , 

Introduction. 
In 1905 the Department of Agriculture published Farmers'' 
Bulletin No. 239 on the subject of corrosion of fence 
wire. A large number of complaints had reached the 
Department from farmers in regard to the rapid corrosion 
of steel of modern manufacture used for various purposes, 
and especially for wire fencing. As the same difficulty has 
been constantly met in the use of corrugated iron and 
steel culverts for road drainage, it was decided to begin an 
investigation of the entire subject. The intention has been 
not only to get at the facts in the case, but also to aid as 
much as possible in bringing about an improvement in the 
rust-resisting quality of iron and steel used for the special 
purposes mentioned above. 

Coincidently with the beginning of the investigation 
inaugurated by the Office of Public Roads much attention 
began to be given to the same subject by a number of 
prominent metallurgists and chemists, both in this country 
and abroad. The American Society of Mining Engineers, 
at their Washington meeting, held in May, 1905, engaged 
in a discussion of the relative corrosion of iron and steel, 
and a vigorous debate followed the presentation of several 
papers on the same subject at the meeting of the American 
Society for Testing Materials, held at Atlantic City in 
June, 1906. The subject was considered so important that 
the latter Society appointed a Special Committee of ten 
members to make an investigation of it. 

(Note. — Prof. W. H. Walker, of the Massachusetts 
Institute of Technology, a member of this Committee, has 
for some time past been making an independent investi- 
gation of the cause of the corrosion of iron. The writer 

* Jjulletin No. 30, U.S. Department of .Agriculture, Office of 
Piiblic Reads, 



Chemical News, » 
Jan. I, 1009 ' 



Corrosion of Iron, 



has reason to believe that the results of Prof. Walker's 
work will be found to confirm in a large measure the 
observations recorded in this Bulletin. Although con- 
temporaneous, the two investigations have been carried on 
quite independently, except in regard to the development 
of the ferroxyl indicator). 

In the Fanners'' Bulletin mentioned above, on the 
corrosion of fence wire, special attention was given to the 
subject of electrolysis and its effects on wire. The sug- 
gestion was made that lack of homogeneity in the dis- 
tribution of impurities in metal made by rapid modern 
processes might be at the bottom of the trouble. Some 
objection has been raised to this suggestion on the ground 
that, although electrolysis probably plays a large part in 
the rusting of water-pipes and structural iron in the neigh- 
bourhood of electric conduits, it is unlikely that it can be 
considered a prime cause of the rusting or corrosion of iron 
and steel under all circumstances. Nevertheless, acting 
on the suggestion made in \\\is Farmer's Bulletin, some of 
the manufacturers have made a determined effort to turn 
out a metal more resistant to corrosion, and the present 
indications are that these efforts have not been unsuccessful. 

In 1894 and 1895 a series of papers, under the title 
" Rustless Coatings for Iron and Steel," was contributed by 
M. P. Wood to the Transactions of the American Society 
of Mechanical Engineers (1894, ^'^•> 99^ ; 1895, xvi., 350, 
663). In these papers all that was known up to that time 
on the cause and cure of corrosion is presented and ably 
discussed. On page 1070 of the Transactions for 1894 this 
author states : — 

" That there is a continual electrical action of a most 
complex character present in all boilers under steam can 
scarcely be doubted, and the same action, but less 
apparent, is possibly present in all constructions of iron 
when the different members formed of iron and steel of 
various compositions, made by different processes after 
various torturing methods of manufacture to bring them to 
the desired shape, are assembled and put into duty under 
strains and conditions foreign to their nature. It would be 
strange indeed did not some electrical energy manifest 
itself and call for some palliative if not protective means of 
arresting decay." 

It is well known that the various kinds of merchantable 
iron and steel differ within wide limits in their resistance, 
not only to the ordinary processes of oxidation known as 
rusting, but also to other corrosive influences. It is also 
true that different specimens of one and the same kind of 
iron or steel will show great variability in resistance to 
corrosion under the conditions of use and service. The 
causes of this variability are undoubtedly numerous and 
complex, and it is safe to say that the subject is not nearly 
so well understood at the present time as it should be. 

In regard to two points all investigators are agreed, and as 
these furnish at least some common ground it is interesting to 
record them before proceeding to a discussion of the points 
at issue. Iron cannot rust in air or oxygen unless water 
is present, and, on the other hand, it cannot rust in water 
unless oxygen is present. An interesting summary of the 
opinions held by various authorities prior to 1903 has been 
given by Mugdan [Zeit. FJektrochemie, 1903, ix., 442), but 
although a number of investigators have worked on the 
problem since that time, the fundamental reactions which 
take place when a bright strip of iron immersed in water 
becomes coated with the red hydroxide known as rust are 
siill a subject of controversy. 

Three separate theories which, though they ail more or 
less overlap, nevertheless involve distinctly different re- 
actions, have been advanced and strenuously defended in 
the effort to furnish an explanation for the rusting of iron. 
These may be stated as the carbonic acid, the hydrogen 
peroxide, and the electrolytic theories. 

Before any distinct progress can be made in the manu- 
facture of metal that shall be more than ordinarily resistant 
to corrosion, it is of great importance that the underlying 
causes of oxidation should be clearly understood. It is 



the object of this paper to discuss the different theories and 
to present certain evidence recently obtained which bean 

directly upon the subject. 

The Carbonic Acid Theorv. 
The carbonic acid theory is the one most generally held, 
and usually presumes that without the interaction of 
carbonic or some other acid the oxidation, or better, the 
hydroxylation, of iron cannot take place. The theory is 
best set forth in the words of a textbook recently published 
(Treadwell and Hail, "Analytical Chemistry," 1907, 
p. 92) :— 

"The process of rusting is a cyclical one, and three 
factors play an important part:— (i) An acid, (2) water, 
(3) oxygen. The process of rusting is always started by an 
acid (even the weak carbonic acid suffices). The acid 
changes the metal to a ferrous salt with evolution of 
hydrogen : 2Fe-^2H2C03 = 2FeC03-^-2H2. 

Water and oxygen now act upon the ferrous salt, causing 
the iron in this salt to separate out as ferric hydroxide, setting 
free the same amount of acid which was used in forming the 
ferrous salt : 2FeC03-f-5H20 + - 2Fe(OH)3-f-2H2C03. 

The acid which is set free again acts upon the metal, 
forming more ferrous salt, which is again decomposed, 
forming more rust. A very small amount of acid therefore 
suffices to rust a large amount of iron. If the acid is 
lacking, the iron will not rust. If we desire to prevent this 
rusting, we must neutralise the acid, e.g., add milk of lime. 
Iron remains bright under an alkali." 




Fig. I.- 



-Api'aratus to s}iow the Action on Iron or 
PuRK Water and Oxvoen. 



Probably no better example than this could be cited to 
show the text-book tendency to supply a complete explana- 
tion of a well-known phenomenon, the underlying causes 
of which are still imperfectly understood. Although the above 
explanation is sufliciently plausible, and in spile of the 
fact that carbonic acid, as well as other acids, do act a part 
in the ordinary rusting of iron, it will presently be shown 
that iron readily oxidises, not only when carbonic acid is 
entirely absent, but also in dilute alkaline solutions. It is 
only when the hydroxyl ions supplied by an alkaline solu- 
tion have reached a certain concentration that rusting is 
entirely prohibited. 

The carbonic acid theory was founded originally on the 
investigations of Crace Calvert (Mem. Manchester Lit. 
Phil. Soc, i87r, v., 104), as interpreted by Crum Brown 
{Jonrn. Iron and Steel Inst., 1888, p. 129). It has also 
more recently been vigorously defended by Moody (Proc. 
Chem. Soc, 1906, xxii., roi), who insists that with water 
and oxygen quite free from carbonic acid iron cannot rust. 
This view is, however, not shared by Dunstan, Jowett, 
and Goulding [yourn. Chem. Soc, 1905, Ixxxvii., Part II., 



lO 



Corrosion of Iron. 



Chemical News, 
I Jan. r, 1909 



1548), or by Whitney (yourn. Am. Chein. Soc, 1903, xxv., 
394) or Cribb (The Analyst, 1905, xxx., 232), all of whom 
give experimental evidence to show that rusting takes 
place rapidly in the absence of carbonic acid, provided 
liquid water and oxygen are present. The experiment of 
Dunstan and his co-workers was so carefully carried out 
that there seems to be no doubt that if carbonic acid 
plays any role whatever it is an unimportant one, 
and that rusting can go on with extreme rapidity in its 
absence. 

In order to confirm this conclusion, the following experi- 
ment was made by the writer : — 

The Jena glass flasks a, b, and the beaker c, shown in 
Fig. I, were nearly filled with freshly distilled water, and 
boiled vigorously for one half-hour. While the boiling 
was still proceeding bright polished strips of charcoal iron 
and steel were slipped into flasks a and b, and the rubber 
stoppers, which had been previously cleaned by prolonged 
boiling in pure water, tightly inserted. After boiling for 
fifteen minutes longer the clamp at the end of tube d was 
opened for a moment, and the back pressure allowed to drive 
any last traces of air from the tube. After tightly closing 
the clamp again, the lamps under flasks a and b were 
removed, while the water in c was still kept boiling. 
Boiled water immediately sucked back until the whole 
apparatus was completely filled, no trace of air being 
present. At all events, no slightest trace of rust appeared 
on the bright metal strips when kept indefinitely under this 
boiled water. Pure oxygen from a cylinder was now 
washed perfectly free from last traces of carbonic acid by 
passing the gas through a train of wash-bottles containing 
caustic potash, barium hydroxide, and lime-water. On 
allowing this carefully purified oxygen to enter at d and 
bubble through the system of flasks, rust appeared on the 
bright metal surfaces in five minutes or less, and in one 
hour had become deep and heavy. The action, just as in 
Dunstan s experiments, did not take place evenly all over 
the surface, but in patches, which had the appearance of a 
more or less regular pattern following the physical structure 
of the metal. This experiments has been frequently re- 
peated, with every possible precaution to avoid the entrance 
of even the smallest trace of carbonic acid. On numerous 
occasions a few drops of phenolphthalein indicator was 
added to the boiling water in the three flasks, and invariably 
a pink colour developed, proceeding from the metallic sur- 
faces. This effect will be discussed at length further on, 
and is mentioned at this place as contributory evidence 
that carbonic acid is not necessarily present, as Moody 
believes, before any reaction between iron, water, and 
oxygen can take place. 

If pure dry carbonic acid gas, freed from oxygen by 
passing through several wash-bottles containing pyrogallic 
acid dissolved in sodium bicarbonate solution, was sub- 
stituted for the pure oxygen gas and allowed to enter 
through tube d, no perceptible action took place on a 
bright piece of steel after several hours, although there can 
be no doubt that iron passed to a slight extent into solu- 
tion as ferrous caibonate. Finally, if pure oxygen was 
allowed to enter at the same time and mingle with the 
carbonic acid, corrosion began in a short time. There was, 
however, a difference in the appearance of the rust that 
was formed with and without the interaction of carbonic 
acid. In the presence of carbonic acid the characteristic 
blue-green gradually changing to the red colour peculiar to 
rust was observed. This appearance, as Moody truly 
observes, invariably accompanies the early stage of attack 
when iron is rusting in the presence of carbonic acid. In 
the experiments in which pure oxygen alone was permitted 
to enter the apparatus the blue-green initial stage of 
oxidation was never observed, the red ferric hydroxide 
making its appearance from the first, as it usually does, in 
normal cases of atmospheric rusting of bright iron 
surfaces. 

It may be doubted whether it is possible to boil out all 
caibonic acid fro n the water contained in the apparatus 
shown in Fig. i. Granting that this is the case in regard 



to last traces, it is easily shown that the hydrogen ions 
which would be supplied by a minute quantity of carbonic 
acid are of no more importance than the hydrogen ions 
supplied by the normal dissociation of pure water, and that 
the assumption that carbonic acid must be present is quite 
unnecessary. Whitney (yourn. Am. Chem. Soc, 1903, 
xxv., 397) shows this very clearly in the following 
paragraph : — 

" Assuming the laws of Henry and Dalton to apply to the 
solubility of carbonic acid gas in water, also that the 
solubility of the pure gas under ordinary pressure is one 
volume for one volume of water (which is correct at 15° C), 
and, finally, that the normal content of carbonic acid in 
the atmosphere is 2 parts in 10,000 by volume, we should 
expect water in equilibrium with air containing this con- 
centration of carbonic acid to contain 00002 volume 
carbon dioxide per volume of water. This corresponds to 
a concentration of the carbonic acid equal to oooooi mol. 
per litre, or 000002 normal. From the dissociation con- 
stant 3040 X 10 — 10 determined by Walker (Zeit. Phys. 
Cfiem., 1900, xxxii., 137), it follows that the first hydrogen 
of the acid is 16 per cent dissociated at this concentration. 
From this it follows that 10,000,000 litres of water con- 
taining carbonic acid in equilibrium with ordinary air at 15^ 
contains 16 grms. of hydrogen ions, or only sixteen times 
as many as perfectly pure water contains. At the boiling 
temperature the carbon dioxide dissolved would probably 
yield a concentration of hydrogen ions even less than in 
pure water, for not only is the solubility of the gas greatly 
diminished, but the dissociation of water is greatly in- 
creased by rise of temperature. Moreover, the distilling 
water would rapidly reduce the concentration of any 
carbonic acid capable of dissolving in water at 100" C." 

Moody prepared an apparatus in which the presence or 
subsequent entrance of even the smallest traces of carbonic 
acid was elaborately guarded against. The apparatus was 
constructed entirely of glass, and was arranged in such a 
manner that polished cylinders of almost pure soft Swedish 
iron could be subjected to the action of water, and air 
absolutely free from carbonic acid. Even with the very 
pure iron and with water which was undoubtedly rendered 
slightly alkaline by its intimate contact with a large surface 
of ordinary glass. Moody observed a slight amount of 
corrosion taking place on his bright iron surfaces. Still 
convinced, however, that the presence of carbonic acid was 
necessary before the slightest rusting effect could be pro- 
duced, and believing that in some unknown manner an in- 
finitesimal amount of this substance had eluded his 
vigilance. Moody began again with a new and quite 
extraordinary precaution. Before the bent tube, which 
contained the polished specimen of iron was fused into its 
place in the apparatus, it was partly filled with a i per cent 
solution of chromic acid which just covered the iron. 
When the apparatus had been swept with air free from 
carbonic acid for three weeks, water was distilled through 
the tube containing the specimen until the chromic acid 
was all washed away. After this, as well as the added 
precaution of covering the ends of the iron cylinders with 
wax to prevent contact with the glass (as an interaction 
between glass and iron appeared also to cause corrosion 
even if no carbonic acid was present), the experiment was 
finally a complete success. In one case a current of air 
was passed through the apparatus for five weeks without 
even one speck of rust appearing. 

If Moody's experiment could be accepted as final, we 
must conclude that in an atmosphere that did not, like that 
of this earth, contain about 004 per cent of carbonic acid, 
the rusting of iron would be an unknown phenomenon. 

It happens, however, that a recent observation of the 
writer explains the negative result obtained by Moody, 
without any reference whatsoever to the carbonic acid 
theory of rusting. It has long been known that rusting 
is inhibited, and that polished iron will remain bright 
indefinitely in alkaline solutions, provided they are suffi- 
ciently concentrated. This is also true of all solutions of 



Chemical News, 1 
Jan. I, 1909 



Technical Methods of Chemical Analysis. 



II 



salts of strong bases and weak acids which hydrolyse to an 
alkaline reaction {Zeit. Elektrochemie, 1903, ix., 446). 
This fact has been eagerly seized upon by the adherents of 
the three theories, as it can be made to fit in more or less 
well with them all. Thus, alkalis absorb carbonic dioxide, 
and therefore carbonic acid is prevented from carrying on 
its work of destruction. The added fact that fully 
saturated bicarbonate of soda also provides full protection 
to iron, even in fairly dilute solution, which would seem to 
be a stumbling block, has not shaken the faith of the 
devout believers in the carbonic acid theory. 

The adherents of the peroxide theory claim that iron 
cannot rust unless hydrogen peroxide is formed as a 
transition step in the reactions. As hydrogen peroxide is 
more or less unstable in alkaline solutions it is claimed that 
iron should not rust when immersed in them. The added 
fact that the rusting of iron is actually accelerated by 
solutions of potassium iodide, iodine, dilute potassium per- 
manganate, and other substances which also destroy 
hydrogen peroxide, must apparently be accepted as an 
exception which proves the rule. The theory of electrolysis 
alone finds no difficulty in appropriating the facts of the 
alkali inhibition of oxidation. The full discussion of this 
point, however, must be postponed to a later portion of 
this Bulletin. 

As far as the writer is aware, Dunstan and his co- 
workers were the first to make use in a theoretical discus- 
sion of the fact that solutions of chromic acid, potassium 
chromate, and potassium bichromate exercise a complete 
protection from rust to the surfaces of iron specimens im- 
mersed in them. It is probable, however, that the pro- 
tective power of the chromates and some other oxidising 
agents has been known, and to some extent made use of, 
in a practical way for a long time past (Trans. Am. Chcni. 
Soc. Eiig., 1894, xvi., 384). Wood stated in 1894 that a 
few substances, such as red-lead, pyrolusite, the bichromate 
of potash, and chromate of lead, were gradually coming 
into use for anti-corrosive paint compounds, and that their 
future use for this purpose was assured. This peculiarity 
of the chromates was interpreted by Dunstan as furnishing 
a proof of the peroxide theory, as it is well known that 
hydrogen peroxide is destroyed by chromic acid and its 
salts. 

The writer has gone a step further, and observed that the 
protection afforded by chromic acid and its salts differs 
from that of the alkalis in that the passivity is in a sense 
acquired by the surface of the iron, and lasts for long 
periods, although the chromated specimens may have been 
washed with all possible care, and even wiped with a 
cloth. In the writer's experiments all chromating has 
usually been done by immersing polished specimens of iron 
and steel in a strong solution of potassium bichromate for 
a number of hours, generally over-night. Steel-wire nails 
treated in this way have been kept under water in vessels 
open to the contact of air and carbonic acid for many 
weeks without developing the slightest speck of rust or 
tarnish on their polished surfaces. In addition to this, 
polished specimens which have been chromated have been 
kept in moist air for weeks at a time without losing their 
passive condition. This astonishing phenomenon is so 
easily and quickly demonstrated by any one who cares to 
make a trial of it that it is not necessary in this place to 
include evidence to support the statement made above. 
The subject will be taken up in detail later on, and it is 
only mentioned here to show that Moody's experiment does 
not prove that the presence of carbonic acid is necessary 
before iron can rust. It must, of course, be admitted that 
the presence of hydrogen ions will hasten the corrosion of 
iron, and therefore the presence of a small amount of 
carbonic acid plays a minor role. The point that is made 
is that carbonic acid is not necessary, and that rusting can 
go on with extreme rapidity without it. If Moody had 
used pure oxygen instead of air he would undoubtedly 
have rusted his specimens in spite of their having been 
first chromated. 

(To be continued). 



NOTICES OF BOOKS. 

A Treatise on Colour Manufacture. By George Zerr 
and Dr. R. Rubencamp. Authorised English Edition 
by Dr. Charles Mayer. London : Charles Griffin 
and Co., Ltd. 1908. 
The German edition of this work was a book whose 
merits were immediately recognised, and one which met 
with much success ; no doubt the English version will be 
equally appreciated, for though small alterations have been 
made, in the main it reproduces very faithfully the good 
features of the original. The different colouring matters 
are classified according to a convenient system, and each 
individual substance is given thorough treatment, some 
notes being occasionally added by the translator. A short 
summary is given of the coal-tar colours, and also some 
account of the uses of colours, which, however, is perhaps 
too much condensed to be of any practical good to the 
specialist. It is unfortunate that some very important 
recent advances, as in the analyses of lake pigments, are 
not described in the text, although in many cases the 
translator calls attention in a footnote to books and 
articles which may be consulted for the most recent 
information. 



Technical Methods of Chemical Analysis. Edited by 
George Lunge, Ph.D., Dr.Ing. English Translation 
Edited by Charles Alexander Keane, D.Sc, Ph.D. 
Volume I., Parts I. and II. London: Gurney and 
Jackson. 1908. 
The English translation of this standard work on chemical 
analysis has been prepared from the second German 
edition, issued in 1904, and in many respects it must be 
regarded as a unique production. Each section, which was 
written by an expert in the first case, and represented the 
last word on analytical practice in Germany, has again 
been revised by an expert who has a special knowledge of 
the conditions of English manufacture where they differ 
from those which hold in Germany, and of the require- 
ments of English chemists. The references to literature 
have been altered so that English books and articles are 
substituted for German, and where necessary the text has 
been brought up to date by Prof. Lunge and the English 
editor. The treatise fulfils a double purpose, being both a 
work of reference, summarising all well-established methods 
of analysing the raw materials, intermediate, and final pro- 
ducts of the different industries, and also a practical 
laboratory guide describing the performance of the most 
satisfactory methods in the ca.se of each substance. 
Volume I. has been issued in two parts, which contain, 
firstly, a complete introduction to chemical analysis, dis- 
cussing all the methods employed with full details of the 
operations with which the chemist should be familiar. In 
addition many important groups of industries are treated, 
including the manufacture of acids, salt-cake, sodium 
carbonate, clay, glass, &c., while the analyses of air, 
water, sewage, soils are among the subjects treated in the 
second part, 

Catalogue of Balances and Weights. London : F. E. 

Becker and Co. (W. and J. George, Ltd., successors). 

1908. 
This new balance catalogue is so excellently illustrated, 
and all the apparatus enumerated in it is described with 
such careful attention to every important detail, that no 
customer need entertain any doubt about the wisdom of 
ordering an article without having actually seen and 
handled it. The firm is renowned for the reliability and 
good finish of the instruments they put upon the market, 
and their prices must be acknowledged to be surprisingly 
low in some cases, especially when it is remembered that 
the name Becker is a guarantee of accuracy and good 
wearing properties. Various forms of specific gravity and 



l2 



Meetings for the Week. 



ClfKMlCAL Nr.ws, 
Jan. I, 1909 



spring balances are illubtrated in the catalogue, and, in 
addition, all accessories are listed, including forceps, spirit 
levels, sets of weights, and triangular calcium chloride 
vessels. 



Catalogue 0/ Apparatus for Chemical Lecture Experiments. 

London : A. Gallenkanip and Co., Ltd. igo8. 
Tuts catalogue of apparatus for chemical lecture experi- 
ments contains a price list of the whole range of Ilofmanns 
and Newth's lecture apparatus with some valuable addi- 
tions, and full descriptions are given of some of the instru- 
ments with directions for their manipulation. The time of 
the chemical lecturer or demonstrator will be much 
economised by the use of some of this apparatus, which is 
comparatively inexpensive, while sometimes troublesome 
to fit up from the ordinary laboratory stores. Attention 
must be called to the description of an optical lantern for 
horizontal and vertical projection, which would appear to 
be a thoroughly satisfactory instrument. 



A Scheme for the Promotion of Scientific Research. By 
Walter B. Priest. Second Edition. London : Stevens 
and Sons, Ltd. 1908. 
The second edition of this book is a reprint of the first, 
except that it contains seme fuller explanations and details, 
more especially of the question of assessment in the 
author's scheme for endowing scientific research. The 
plan seems workable, and in view of the excellence of the 
object which it aims at promoting, it would perhaps be 
invidious to lay too much stress on obvious defects and 
difficulties which are chiefly concerned with the assess- 
ment of the grants to be made. The author regards dis- 
coveries by which the mortality arising from various 
diseases may be lowered as deserving special attention and 
most liberal recognition, but the scheme might easily be 
extended to other fields of research. The procedure re- 
commended is based upon the Patents Act of 1883, sections 
and subsections of which are quoted in an appendix. The 
author writes with moderation, and it seems probable that 
the adoption of his scheme would give an impetus to 
scientific research, and thus benefit civilisation. 



Cours de Chimie Inorganiqne. (" Course of Inorganic 
Chemistry "). By Freb. Swarts. Paris : A. Hermann. 
igo8. 
This book occupies an intermediate position between those 
text-books which are rigidly divided into two parts — 
theoretical and descriptive — and the more modern ones in 
which the treatment corresponds to the heuristic oral 
method of teaching, and theories are only suggested to 
explain facts which have already been observed or studied. 
Thus it belongs to the old type in that in a general intro- 
duction the atomic and other fundamental theories are dis- 
cussed, while descriptions of the properties, preparation, 
&c., of each individual element follows. But, on the other 
hand, throughout the descriptive part are to be found dis- 
cussions of the theoretical aspects of the various pheno- 
mena considered. The book is based upon the course of 
chemistry for engineering students at the Universityof Gand, 
and is thus not intended for the use of young beginners. 
Although it is perhaps not a work which a student could 
be advised to read straight through, it is in many ways not 
unsuitable lor him if he has the advantage of having a 
competent teacher to decide in what order the chapters are 
to be read. The student will find the frequent heavy type 
and the short paragraphs employed are helpful, and, on 
the whole, he will be able to gain from the book a very 
fair notion of descriptive chemistry, including some metal- 
lurgy and industrial processes. One chapter is given to 
thermochemistry and is a good feature, but a serious defect 
is the omission of all allusion to the Periodic System. It 
is now generally recognised that an outline of the main 
features of the system give interest to the study of 



inorganic chemistry, and enable greater calls to be made 
upon the students' deductive powers and less upon his 
memory — thus tending to remove a reproach from the 
science as an educative subject. Moreover, the generalisa- 
tions of the Law give the beginner a much sounder know- 
ledge of chemistry than he can get from the study of 
isolated and apparently unconnected reactions and 
properties 



Salpeter itnd scin Ersatz. (" Saltpetre and its Sub- 
stitutes"). By KoNRAD W. JuRiscH. Leipzig: S. 
Hirzel. igo8. 
The growth in importance and magnitude of the chemical 
industries connected with the artificial production of nitro- 
genous manures demands new books dealing with them, 
and this treatise on saltpetre is, no doubt, the forerunner 
of many similar works. The first part of it deals with the 
extraction, preparation, analysis, &c., of ordinary and 
Chili saltpetre ; methods of analysis are given only in out- 
line, and certain by-processes, such as the preparation of 
nitric acid, the chemistry and technology of ammonia, are 
not discussed, but full bibliographies, dating in one case 
from 1895 and in the other from 1830, of the literature of 
the subjects in all languages are given, together with some 
additional notes on important articles and books. The 
needs of plants as regards nitrogenous manures are dis- 
cussed in some detail, and illustrations of the influence of 
different manures on the growth and development of 
plants are reproduced. The preparation and properties 
of calcium cyanamide are treated fully, and also the pro- 
duction of nitric acid from the air. The different factories 
which have sprung up in Norway are described and 
illustrated, and the rapid growth of this particular industry 
is made very evident. 



Kolloidchemische Stiidien am Eiiceiss. (" Studies in 
Colloidal Chemistry with Albumen "). By W. Pauli. 
Dresden : Theodor Steinkopff. 1908. 
This monograph is a reprint of a lecture which was 
delivered in \'ienna in June, igo8, and published in the 
July number of the Zeitsc/irift fi.r Chcmic und Industrie 
der Kolloide. Its issue as a separate publication is 
justified by the admirable survey it gives of the author's 
valuable researches on albuminous substances and the 
effects of salts upon them. These researches, which led 
to some results of the greatest importance, were ably con- 
ceived and skilfully performed, and were specially aimed 
at the reproduction of the conditions which obtain in the 
living organism, so that their application to the solution 
of physiological problems is at once apparent. One of the 
most important results obtained was the demonstration 
that the ions of neutral salts form adsorption compounds 
with albuminous substances, a theory which was put 
forward some time ago by the author and Prof. Loeb. 
Besides describing the experimental arrangements and the 
conclusions to be drawn from the results obtained, the 
author discusses briefly the bearing of his own and other 
investigators' work on physiological problems ; he holds 
the view that the albuminous constituents of the plasma 
are the substances which are first attacked by the ionised 
compounds. 



MEETINGS FOR THE WEEK. 

Monday, 4th. - Soi-iety of Chemical Industry, 8. " Cinchonamine 
and certain other Rare Alkaloids," by H. F. Howard 
and O. Chick. "Theory of Dyeing," by W. P. 
Dreaper. " A Physico-chemical Method for coin- 
paring the Antiseptic Value of Disinfectants," by 
S. B. Schryvcr and R. Lessing. 
TutsDAY, 5th. \ Royal Institution, 3. (Christmas Lectures 
Thursday, 7th. - adapted to a Juvenile Auditorv). " The Wheel 
Saturday, gth. ) of Life," by Prof. W. Stirling, M.D., &c. 

Wednesday, Gth. Royal Society of Arts, 5. (Juvenile Lecture). 
"Digging for Ancient Art Treasures," by Chas. 
Wald$tein. 



Chemical News, I 
Jan. 8, 1909 I 



Measurement of Rotatory Dispersive Power. 



13 



THE CHE MICM NEWS 



Vol XCIX., No. 2563. 



I 



MEASUREMENT OF ROTATORY DISPERSIVE 

POWER IN THE VISIBLE AND ULTRA-VIOLET 

REGIONS OF THE SPECTRUM.* 

By T. MARTIN LOVVRY, D.Sc, 

Lecturer on Physical Chemistry and Instructor in Crystallography 

at the Central Technical College. 

The following is a brief preliminary account of improve- 
ments effected in the method of determining rotatory 
dispersive power which have made it possible to observe 
accurately not only in the bright regions of the visible 
spectrum, but throughout the scale from the region of the 
lithium red line into that commanded by the photographic 
plate. 

Two methods have generally been used for the purpose, 
namely, (i) Broch's method, in wkich a spectroscope is 
arranged in series with the polarimeter and a narrow strip 
of a continuous spectrum is picked out for observation — a 
method which is much improved by using a constant- 
deviation spectroscope in place of one of the variable- 
deviation type (F. Twyman, Phil. Mag., 1907, xiii., 481), 
and (2) Landolt's method, in which a white light is reduced 
by means of filters to approximate homogeneity in the red, 
green, light blue, or dark blue parts of the spectrum. 
Neither method fulfils the fundamental condition that the 
field of the polarimeter shall be uniformly lighted with 
monochromatic light — many of the measurements that 
have been made, therefore, possess only a qualitative 
value. A much better method is due to the late Sir 
William Perkin, who introduced the use of a spectroscope- 
eyepiece as a means of purifying the sodium light, and 
used it on a limited scale for measuring rotatory dispersive 
power in the red (lithium), yellow (sodium), and green 
(thallium) parts of the spectrum. 

The method now described resembles Perkin's method 
in its essential feature, namely, the use of monochromatic 
or multichromatic light (spectroscopically purified) in place 
of a band from a continuous spectrum. It has the advan- 
ta«^e that it renders available for polarimetric measure- 
ments, in addition to the flame spectra, the large series of 
intense line spectra produced by the metallic arcs, which, 
with the one exception of the enclosed mercury arc (Disch, 
An/i. Phys.., 1903, U\, xii., 1155). ^° "O* appear to have 
been used previously for this purpose. Up to the present, 
measurements have been made with 26 lines ranging from 
wave-length 6708 to 4359 ; beyond these limits the visual 
intensity of the light is so small that polarimetric observa- 
tions become very difficult, but in the intermediate part of 
the spectrum the list might, without difficulty, be extended 
considerably. The mercury lines referred to in the table 
were produced by a Bastian lamp ; the copper and zinc 
spectra were produced by means of copper or brass elec- 
trodes rotating in opposite directions, as recommended by 
Baly in the case of the iron arc ; the cadmium spectrum 
was obtained by means of rotating copper or silver 
electrodes coated with the metal. 

In order to utilise the arc spectra for polarimetric obser- 
vations, a parallel beam from the arc is thrown on to the 
widely-opened slit of a constant deviation spectroscope. 
An achromatic lens of 22" focus is substituted for the 
observing telescope of the spectroscope, and is used to 
cast a magnified image of the slit on to the polarismg 
prisms which produce the horizontally-divided triple field 
of the polarimeter. By turning the constant-deviation 
prism to a suitable position, the field can be illuminated 
from top to bottom by a brilliant band of pure mono- 
chromatic light, the maximum width of the band being 



♦ A Paper read before the Royal Society, November ig, 1908. 



determined by the openness of the spectrum and, in a very 
important manner, by the efficiency of the dispersive 
system. By using a CD. prism of high density in con- 
junction with the long-focus lens, it is possible to read 
separately the two lines 5790 and 5769 which constitute 
the yellow mercury doublet, although these differ in wave- 
length by only 21 Angstrom units ; the yellow doublet and 
green triplet in the copper spectrum can be read with ease 
and accuracy as broad bands each occupying a width 
rather greater than one-third of the 8 mm. aperture of the 
triple field ; the chief lines in the mercury and cadmium 
spectra can be made to cover practically the whole field 
without overlapping. In order to eliminate stray light, 
which would give rise to serious errors in the red and 
violet readings, a Perkin spectroscope eye-piece is used. 

In measuring rotatory dispersive power in the ultra- 
violet, a parallel beam of light from an arc formed between 
a carbon and a magnetite electrode is cast directly by a 
quartz condenser on to the triple field of the polaiiser, 
Foucault prisms being substituted for the Nichol prisms to 
ensure transmission. A quartz-calcite lens of 13" focus 
is substituted for the analyser-telescope ; this casts a 
diminished image of the triple field on the slit of an ultra- 
violet spectroscope. The spectrum thus produced is 
photographed in the ordinary way by means of a camera 
provided with a quartz calcite lens of 22" focus; the 
division produced by the triple field can be seen clearly, 
and it is easy to pick out and identify on the negative the 
line which is of equal intensity in its three sections. By 
taking photographs with the analyser in different positions 
it is possible to determine the rotatory power of a sub- 
stance throughout the transmitted spectrum. 

The results obtained with water, carbon bisulphide, and 
other liquids in a magnetic field will be dealt with in a later 
communication ; the method is one which is likely to be of 
special value as affording a means of determining the 
homogeneity of apparently simple liquids. In the table 
below the results are reliable within two or three units in 
the last figure. 

The polarimeter readings shown in the table were usually 
concordant within a few hundredths of a degree ; the 
absolute values may differ by as much as 1° in different 
specimens of the ester, but the relative values, a/ id, are 
probably reliable within one or two units in the last figure. 

Table of Wave-lengths used in the Measurement 0/ Rotatory 
Dispersive Power, together with the Rotations pro- 
duced by 100 mm. of Methylic Camp hocar boxy late at 
20° C. 

Wave-length. a. o/ao- 

Li red 6708 4832^ 0728 

Cd red .. .. 6438 53-41 0-805 

Zn red . . . . 6364 54-91 0-827 

Na yellow . .. 5893 66-37 ''ooo 

Hg yellow . .. 5790 69-40 1046 

Cu yellow . .. 5782 69-83 1-052 

Hg yellow . . . 5769 70-09 1-056 

Cu yellow . .. 5700 72-38 1-090 

Ag green . . .. 5469 80-75 i'2i7 

Hg green . . .. 5461 80-94 1-220 

Tl green .. .. 5351 85-59 i"290 

Cu green . .. 5219 91-73 1-382 

Ag green . . .. 5209 Q^'J? ''389 

Cu green.. .. 5154 94"93 ^HSO 

Cu green . . .. 5105 97-52 1-469 

Cd green . . .. 5086 98-60 1-486 

Znblue .. .. 48" ii6'i5 I750 

Cdblue .. .. 4800 116-93 1-762 

Znblue .. .. 4722 122-92 1-852 

Cublue .. .. 4705 124-38 1-874 

Znblue .. .. 4680 126-36 1-904 

Cdblue .. .. 4678 "6-55 1-907 

Cublue .. .. 4651 ^28-34 1933 

Cu blue . . . . 4587 i34'<5o 2-028 

Cu violet . . . . 4378 i57"62 2-375 

Hg violet.. .. 4359 165-07 2-487 



14 



Corrosion of Iron. 



< Chemical News, 
Jan. 8, 1909 



THE SPECTRUM OF SCANDIUM 
AND ITS RELATION TO SOLAR SPECTRA.* 

By A. FOWLER, A R.C.S .F.R.A.S., Assistant Professor of Physics, 
Imperial College of Science and Technology, South Kensington. 

The greater part of this investigation of the spectrum of 
scandium under different experimental conditions has been 
based on purified scandia, generously placed at the author's 
disposal by Sir William Crookes. The principal results 
are as follows : — 

1. The arc spectrum of scandium consists of two distinct 
sets of lines, which behave very differently in solar spectra. 
Each set includes both strong and faint lines. 

2. Lines belonging to one set correspond with the 
enhanced lines of other elements, notwithstanding that 
they appear strongly in the ordinary arc spectrum — 

(a) These lines are very feeble or missing from the arc- 

flame spectrum, and are strengthened in passing to 
the arc, the arc in hydrogen, or the spark. 

(b) They occur as relatively strong lines in the Fraunhofer 

spectrum. 
{c) They are weakened in the sun-spot spectrum, 
(rf) They occur as high-level lines in the chromosphere. 

3. The remaining lines show a great contrast when com- 
pared with the first group — 

(a) They are relatively strong lines in the arc-flame. 
(6) They are very feebly represented in the Fraunhofer 
spectrum. 

(c) The stronger lines are prominent in the sun-spot 

spectrum. 

(d) They have not been recorded in the spectrum of the 

chromosphere. 

4. The special development of the enhanced lines in the 
Fraunhofer spectrum, together with their presence in the 
upper chromosphere, indicates that the greater part of the 
scandium absorption in the solar spectrum originates at a 
higher level than that at which the greater part of the iron 
absorption is produced. 

5. The discussion of scandium lines indicates that while 
in the case of some elements solar identifications are to be 
based chiefly on arc lines, in others it is the enhanced 
lines which may be expected to show the most important 
coincidences. 

6. The fiutings which occur in the arc and arc-flame do 
not appear when the arc is passed in an atmosphere of 
hydrogen. As suggested by Thalen, they are probably 
due to oxide of scandium. 

Tables are given which show the lines of the arc 
spectrum from 3930 to 6580, the positions of the oxide 
flutings, and comparisons of the principal lines of the two 
classes with the sun, sun-spots, and chromosphere. 



Decomposition of Diazo Solutions. — A. Hantzsch 
and K. J. Thompson. — After diazonium chlorides have 
been left for a long time in the desiccator, or dry air has 
been passed over them, they give the maximum value of 
the velocity of decomposition in aqueous solution. Freshly 
prepared solutions decompose more slowly and seem to 
contain some unknown substance which hinders decom- 
position. Dilute bromide solutions decompose at the same 
rate as the chloride. The velocity of decomposition in- 
creases very slowly with the concentration, that of the 
bromide solution rather more quickly than the chloride. 
Diazoiodide solutions even when very dilute decompose 
much quicker, and nitrobenzene diazonium solutions also 
decompose rather more quickly in very concentrated solu- 
tions ; acids do not affect the decomposition of the last 
named compounds. — Berichte, xli., No. 14. 

♦ Abstract of a Paper read before the Royal Society, June 25, 1908. 



THE CORROSION OF IRON.* 

By ALLERTON S. CUSHMAN, 
Assistant Director, Office of Public Roads, Dept. of Agriculture, U.S.A. 

(Continued from p. 11). 

The Peroxide Theory. 
DuNSTAN, Jowett, and Goulding based their peroxide 
theory of the rusting of iron on the general well-known 
theory of oxidation advanced by Traube (Ber., xviii., 1881). 
Thus the chemical reactions concerned in the formation of 
iron rust should be written . — 

Fe -(- O2 + H2O = FeO + H2O2, 
2FeO f H202 = Fe202(OH)2 = Fe203,H20. 

The excess of hydrogen peroxide immediately reacts 
with the iron, forming a further quantity of rust : — 
Fe + H202 = FeO + H20, 
2Fe0 + H2O2 = Fe202(0H)2 = Fe203,H20. 

Some of the evidence brought forward to substantiate 
this theory has already been referred to in a previous 
paragraph. It appears to derive some confirmation from 
the fact that delicate tests for hydrogen peroxide have been 
obtained during the slow oxidation of zinc and some other 
metals. On the other hand, in the case of iron these same 
delicate tests obstinately refuse to reveal even its transitory 
presence during the ordinary process of rusting. The 
theory has been criticised by Divers (Proc. Chem. Soc, 
1905, xxi., 251), Moody (yourn. Chem. Soc., 1906, Ixxxix. 
— ex., 720), and Cribb (Analyst, 1905, xxx., 225) — the 
first-named having pointed out that it is not tenable to 
argue that, because such substances as chromic acid and 
alkalis gradually destroy hydrogen peroxide, they must 
prevent its formation. For instance, ferrous sulphate is 
oxidised by free chlorine, but it does not prevent man- 
ganese dioxide and hydrochloric acid from reacting when 
brought together in its presence. Moreover, if the forma- 
'' tion of hydrogen peroxide was a necessary stage in the 
rusting of iron, and this is inhibited by certain substances 
which destroy hydrogen peroxide, why is not the inhibition 
extended to strong reducing agents generally ? The theory 
is an interesting and suggestive one, but in the author's 
opinion is not supported by the facts. 

The Electrolytic Theory, 
From the standpoint of the modern theory of solutions, 
all reactions which take place in the wet way are attended 
with certain re-adjustments of the electrical states of the 
reacting ions. The electrolytic theory of rusting assumes 
that before iron can oxidise in the wet way it must first 
pass Into solution as a ferrous ion. The subject has been 
interestingly treated by Whitney (loc. cit., p. 10), who 
discussed it from the standpoint of Nernst's conception of 
the source of electro-motive force between a metal and a 
solution. When a strip of metallic iron is placed in a solu- 
tion of copper sulphate, iron passes into solution and 
copper is deposited, this change being of course accom- 
panied by a transfer of electrical charge from the ions of 
copper to those of iron. Hydrogen acts as a metal, and is 
electrolytically classed with copper in relation to iron. If 
therefore we immerse a strip of iron in a solution con- 
taining hydrogen ions, an exactly similar reaction will take 
place, iron will go into solution, and hydrogen will pass 
from the electrically charged or ionic to the atomic or 
gaseous condition. In such a system the solution of the 
iron, and therefore its subsequent oxidation, must be 
accompanied by a "precipitation" or setting free of 
hydrogen. It is very well known that solutions of ferrous 
salts as well as freshly precipitated ferrous hydroxide are 
rapidly oxidised by the free oxygen of the air to the 
ferric condition, so that if the electrolytic theory can 
account for the original solution of the iron the explanation 
of rusting becomes an exceedingly simple one. 



* Bulletin No. 30, U.S. Department of Agriculture, Office ol 
Public Roads. 



Chemical News, i 
Jan. 8, rgog ' 



Corrosion of Iron 



15 



As iron has been shown by Whitney, Dunstan, and the 
writer to rust in the presence of pure water and oxygen 
alone, the electrolytic theory as a fundamental cause of the 
wet oxidation of iron must stand or fall on the determina- 
tion of one crucial question, viz. : — Does iron pass into 
solution, even to the slightest extent, in pure water ? If 
iron does dissolve, the electrolytic theory is so far satis- 
factory ; if it does not dissolve, we must conclude that the 
oxygen finds some way of directly attacking the metal. 

Almost everyone will admit that in the case of impure 
iron, with its unhomogeneous physical and chemical con- 
stitution, electrolysis will supervene, but it must be remem- 
bered that we are now concerned with the underlying 
cause of the wet oxidation or hydroxylation of iron, re- 
gardless of its state of chemical purity. 

According to the dissociation theory, even the purest 
water contains free hydrogen ions to the extent of about 
I grm. in 10,000,000 litres. If iron dissolves in the purest 
water it should be by intei change with hydrogen, and as 
Whitney (loc. cit., p. 10) has pointed out, pure water is to 
this extent an acid. In order to get experimental evidence 
on this crucial point, Whitney describes the following 
experiment : — 

" A clean bottle was steamed out for a time to remove 
soluble alkali from the glass, and was then filled with pure 
distilled water, which was kept boiling by passing steam 



These investigators do not believe that hydrogen is evolved 
during the rusting of iron, or that iron dissolves even to 
the slightest extent in pure water. They also claim that 
the electrolytic theory affords no explanation that sub 
stances such as chromic acid and potassium bichromate 
inhibit the rusting of iron. The description of the experi- 
ment on which Dunstan based his opposition to the 
electrolytic theory is quoted verbatim, as follows: — 

" A flask of 600 cc. capacity, filled with distilled water, 
was boiled for fifteen minutes; two pieces of purified iron, 
each about ij inches square, was then placed in the flask, 
and an indiarubber stopper carrying a glass tube which pro- 
jected 7 to 8 inches above the stopper and ended in a 
capillary was fitted into the neck of the flask, the water 
being kept boiling continuously. The water was allowed 
to boil for five minutes longer, when the capillary was 
sealed and the stopper coated with parafiin-wax. This 
flask was left at the ordinary temperature for three weeks, 
in the course of which no visible change occurred. It was 
then opened, when one-half of the liquid was quickly 
poured into a beaker, the other half being left in contact 
with the iron in the flask. The liquid in the beaker on 
exposure to the air showed no cloudiness, no yellow 
coloration, and no separation of rust. In fact, on testing 
the liquid for iron by the extremely delicate thiocyanate 
reaction not a trace could be detected. The pieces of iron 




Fig. 2. Apparatus used to Determine the extent ov the Solubility ok Iron in Pure Water. 



through it for fifteen minutes. While still boiling, a bright 
piece of iron was placed in the bottle. A stopper (in some 
cases rubber and in others cork) carrying a tube open in a 
capillary several inches above the stopper was inserted into 
the bottle and firmly fastened in place, the water being 
kept boiling. Finally, the glass capillary was heated hot 
by means of a blowpipe, and sealed by squeezing the walls 
together. The bottle was then allowed to cool to a tem- 
perature of about 80° C, and the neck of the bottle was 
finally covered with paraffin to prevent leaking. It was 
thought that in this way the oxygen, carbonic acid, and 
other gases in the water were completely removed. 
Bottles containing iron and sealed in this manner have 
stood without any visible change for weeks. In some 
cases a little air was subsequently admitted to bottles which 
had stood in this way with the iron apparently unaffected, 
and within a few minutes the water became cloudy, and 
assumed a yellow colour. Ordinary rust rapidly deposited 
upon the glass and in spots upon the metal. In fifteen or 
twenty minutes the production of rust throughout the bottle 
was perfectly evident. It seemed plain from the rapidity 
of formation of oxide and its precipitation on the glass 
that the iron had dissolved in the water before the addition 
of the air, and that the latter simply permitted the forma- 
tion of the insoluble oxide." 

Dunstan and his co-workers reviewed and repeated 
Whitney's experiment and failed to confirm his result. 



in the open flask after an hour showed signs of rusting, 
just as in ordinary cases, but the phenomena described by 
Whitney were not observed. We are therefore unable to 
confirm Whitney's statement that liquid water alone is 
capable of dissolving even an infinitesimal quantity of iron. 
This being the case, the theory based on this statement 
becomes untenable." 

It is quite clear that the point at issue is an important 
one, on which hangs the decision as between the two 
theories. In order to obtain more light on the subject the 
writer devised the following experiment, which is suffi- 
ciently simple to be repeated by anyone without encountering 
any difficulties whatever. The apparatus used is shown in 
Fig. 2. 

The two clean Jena glass flasks, a and b, are three-quarters 
filled with pure freshly distilled water. Two drops of an 
alcoholic solution of phenolphthalein indicator (i grm. in 
100 cc. pure alcohol) are added to the water in each of the 
flasks. The beaker c is more capacious than the flasks a 
and B. The flasks d and e are used in each experiment as 
blanks to check the results obtained. After connecting 
up as shown, the water in each vessel is simultaneously 
boiled very vigorously until about one-quarter is boiled off. 
The rubber stopper in a is then lifted, and clean polished 
strips of iron quickly slipped in. The stopper is again 
tightly inserted, and the boiling continued for about fifteen 
minutes. The lamps under A and E are then extinguished, 



i6 



Corrosion of Iron. 



I Chemical News, 
* Jan. 8, igog 



while the water in b, c, and d continues to boil. As soon as 
flasks A and e have sucked back boiling water so that they 
are completely filled, the lamps under flasks b and d are 
also extinguished. When b is quite full, flasks a and b 
are quickly cooled by surrounding them with cold water. 
The valve at f is then closed. By this means the bright 
specimens are immersed in water practically free from air, 
oxygen, or carbonic acid, and may be kept under observa- 
tion for any desired length of time. This experiment has 
been repeated a great number of times with different 
samples of iron and steel, and no rusting has ever been 
observed unless air was allowed to enter. 

It has been shown that the electrolytic theory of the wet 
oxidation of iron is based on the premise that iron must 
first go into solution, an equivalent amount of hydrogen 
being set free. The resulting ferrous hydroxide in solution 
betrays its presence by producing a pink coloration with 
the phenolphthalein indicator. In every experiment made 
the pink colour was seen, although in some cases the 
colour developed slowly and only after the lapse of a 
number of hours. That the colour was not due to the 
action of the water on the Jena glass was shown by the 
fact that no colour appeared on the blank side of the 
experiments. 

Another simple experiment was made in order to deter- 
mine the concentration of hydroxyl ions that must occur 
before a pink colour can be distinctly seen. 550 cc. of 
distilled water containing i cc. of phenolphthalein in- 
dicator was boiled down in a Jena flask to 500 cc. One 
one-hundredth normal potassium hydroxide solution was 
then run into the quickly cooled water from a burette. It 
was thus found that about i cc. of one one-hundredth 
normal potassium hydroxide was the limit of the quantity 
necessary to produce a distinctly visible pink colour ; i cc. 
of one one-hundredth normal potassium hydroxide contains 
o'oooiy grm. of hydroxyl. This quantity in 500 cc. of 
water represents a concentration of about o'35 part of 
hydroxyl per million. Since the flasks shown in Fig. 2 
contain when quite full 360 cc, there must have been 
present a weight of hydroxyl ions approximately equal to 
o'35 X360X io~6 = o'oooi2 grm. OH. This corresponds 
to an amount of ferrous iron dissolved equal to 
11*2 X360 X 10-6 = 000040 grm. Fe. 

In referring to Dunstan's experiment it will be seen that 
he boiled two small pieces of iron ij inches square for only 
five minutes in 600 cc. of water. At the end of the test 
300 cc. was poured off to be tested for iron. It is hardly 
likely under these conditions that, had this experimenter 
added phenolphthalein to the water, he would have reached 
the limit of visibility of the pink colour. Granting, how- 
ever, that he had reached this point, it is apparent that he 
was making tests for iron in a solution that contained in 
each centimetre no more than o'oooooi grm. of iron. By 
carefully evaporating the entire 360 cc. to dryness in a 
clean platinum dish, with especial precaution to avoid the 
entrance of dust, the writer has not only been able to show 
the presence of iron with the ordinary test reagents of am- 
monium thiocyanate and ferrocyanide, but has also quanti- 
tative evidence of the approximate correctness of the 
amount present, as estimated from the visibility of the 
colour produced by phenolphthalein. 

Six polished strips of iron, 2i by J by j-V inch, were 
boiled in flask a in the apparatus shown in Fig. 2, as 
already described. After the water in flask b had sucked 
back, flask a was allowed to stand until a pink colour was 
just visible. The contents of the flask were then evaporated 
to dryness, the phenolphthalein burned off, and the residual 
ferric oxide weighed. The residue weighed 00006 grm., 
equivalent to 00004 grni> o^ iron. 

Since it was thought that some doubt might be felt 
whether even the small amount of phenolphthalein present 
could attack the iron, the experiment was repeated with 
iron and boiled water alone, but the results invariably 
showed that a small amount of iron had dissolved. In 
view of the ease with which these experiments can be con- 
firmed it would seem needless to yield more space to this 



phase of the discussion. It appears to the writer to be 
demonstrated that Whitney was right in his assertion that 
iron goes into solution up to a certain maximum con- 
centration in pure water without the aid of oxygen, 
carbonic acid, or other reacting substances. 

This point established, it becomes apparent that the 
rusting of iron is primarily due, not to attack by oxygen, 
but by hydrogen ions. Absolute confirmation of this view 
will be given later on. 

Stimulating and Inhibiting Effects of certain Substances 
upon the Corrosion of Iron. 

All substances in solution which contain hydrogen tons, 
such as acids, stimulate the corrosion of iron. This is also 
true of salts of strong acids and weak bases, which, 
though perfectly stable in a dry condition, hydrolyse in 
solution to an acid reaction ; or which, though neutral in 
fresh solutions, undergo slow decomposition under the 
action of light, with the formation of acid salts or free 
acid. With certain exceptions, salts which are perfectly- 
neutral in solution do not prevent oxidation but appear to 
aid it by increasing the electrolytic action. All substances 
which develop hydroxyl ions in solution, such as the alkalis 
or salts of strong bases with weak acids, to a certain extent 
inhibit, and, if the concentration is high enough, absolutely 
prohibit the rusting of iron. 

Under the electrolytic theory the explanation of the pro- 
tection afforded by hydroxyl ions is a simple one. Owing 
to the small dissociation of water, hydrogen ions cannot 
exist in a solution in which the hydroxyl ions are in excess. 
As hydrogen ions cannot exist or be locally formed in suffi- 
ciently strong alkaline solutions, no attack is made upon 
the iron, which remains permanently unaltered. If, how- 
ever, the concentration of the hydroxyl ions is not suffi- 
ciently great, electrolysis can go on with an apparent 
stimulation of the pitting effects similar to that produced 
by perfectly neutral electrolytes, such as sodium chloride. 

As has already been noted, solutions of chromic acid and 
potassium bichromate inhibit the rusting of iron. In order 
to determine the concentration necessary to produce com- 
plete protection, a number of polished strips of two dif- 
ferent samples of steel were immersed in bichromate solu- 
tions of increasing concentration, contained in tubes which 
were left quite open to the air. There were twelve tubes 
in each series, ranging by regular dilutions from tenth- 
normal down to ten-thousandth normal. At the end of two 
months the last four tubes showed graded rusting with 
accumulation of ferric hydroxide. No rusting had 
occurred in any of the solutions above tube No. 8, which 
contained six-hundred-and-fortieth normal bichromate, a 
strength corresponding to about 8 parts of the salt in 
100,000 parts of water, or about 2 pounds to 3000 gallons. 
Since solutions of bichromate do not hydrolyse with an 
alkaline reaction, but, on the contrary, are usually slightly 
acid, some other explanation must be found for this remark- 
able phenomenon. On first thought it would seem a 
paradox that a strong oxidising agent should have the 
effect of preventing the oxidation of iron, and yet this is 
precisely the case. If, however, the initial cause of rusting 
is the hydrogen ion, it is possible to believe that under 
certain conditions oxygen would prove the most effective 
of all inhibitors. As has been stated, Dunstan, Jowett, 
and Goulding have claimed that this peculiar action of 
chromic acid and its salts is due to the fact that they 
destroy hydrogen peroxide. This explanation is not satis- 
factory, as has been pointed out, and it is fair to inquire 
whether the electrolytic theory is capable of furnishing a 
solution of the problem. Furthermore, it will be shown 
that additional evidence can be brought forward which 
cannot be made to apply to any other theory. 

The writer has observed that if a rod or strip of bright 
iron or steel is immersed for a few hours in a strong (5 to 
10 per cent) solution of potassium bichromate, and is then 
removed and thoroughly washed, that a certain change has 
been produced on the surface of the metal. The surface 
may be thoroughly washed and wiped with a clean cloth 



Chemical News, I 
Jan. 8, igog J 



Corrosion of Iron. 



17 



without disturbing this new surface condition. No visible 
change has been effected, for the polished surfaces examined 
under the microscope appear to be untouched. If, however, 
the polished strips are immersed in water it will be found 
that rusting is inhibited. An ordinary untreated polished 
specimen of steel will show rusting in a few minutes when 
immersed in the ordinary distilled water of the laboratory. 
Chromated specimens will stand immersion for varying 
lengths of time before rust appears. In some cases it is a 
matter of hours, in others of days or even weeks before the 
inhibiting effect is overcome. 

The passivity which iron has acquired can be much more 
strikingly shown, however, than by the rusting effect pro- 
duced by air and water. If a piece of polished steel is 
dipped into a i per cent solution of copper sulphate, a ten- 
second immersion is sufficient to plate it with a distinctly 
visible coating of copper which cannot be wiped off. A 
similar polished strip of steel which has been soaked over- 
night in a concentrated solution of bichromate and subse- 
quently well washed and wiped, will stand from six to ten 
ten-second immersions in i per cent copper sulphate before 
a permanent coating of copper is deposited. Even a 
momentary plunging of the metal into the bichromate will 
induce a certain passivity, but the maximum effect appears 
to require a more prolonged contact with the solution. 

The first explanation of this phenomenon which 
naturally presents itself is that a thin film of either oxide or 
chromate has been formed on the surface of the metal. It 
is almost inconceivable, however if such a film is formed, 
that it cannot be seen with the aid of a microscope. There 
is evidence which appears to indicate that no such film of 
oxide is formed. It is easy to cover polished iron with a 
visible film of oxide by simply flaming it gently in a Bunsen 
burner. Such films do not succeed in protecting the iron 
either from the rusting or the copper sulphate test. Still more 
convincing than this is the fact that if a polished surface 
which has been rendered passive by immersion in bichromate 
is heated to 100° C. for some hours, its passivity disappears 
and it again behaves in a normal manner. None of the 
oxides or chromates of iron are in any sense volatile com- 
pounds, so that if a solid but invisible film is really formed, 
it is in some manner dissipated by heat. Further than this, 
a chromated strip of iron which is kept in a vacuum soon 
loses its passivity, whereas a similar strip kept under 
ordinary conditions remains passive for long periods. 

The passivity of iron was discovered by Keir in 1790 
(Phil. Trans., 1790, p. 359). Since the phenomenon is pro- 
duced only by strong oxidising agents or by galvanic contact 
when oxygen can separate on the iron, it was explained 
by Faraday, Wiederman, and others {Dammer's Anorg. 
Chem., 1893, '"•' 294) as due to a thin oxide film. 
From the evidence given above, however, it seems that the 
passivity of iron is better explained as a polarisation effect 
produced by the separation and retention of oxygen on the 
surface of the metal. If the rusting of iron is due 
primarily to the action of hydrogen ions, iron in the con- 
dition of an oxygen electrode should be more or less well 
protected from electrolytic attack. 

Keir (Dammer's Anorg. Chem., 1893, "••> 294) observed 
that polished iron which had been immersed in red fuming 
nitric acid was altered in some manner so that its power of 
precipitating silver and copper from their solutions was 
inhibited, and this occurred, in the discoverer's own words, 
without the least diminution of metallic splendour or 
change of colour." In the writer's experience red fuming 
nitric acid does not produce the passive condition as suc- 
cessfully as solutions of chromic acid and its salts. Mugdan 
discussed the passivity acquired by iron which was im- 
mersed in fuming nitric or sulphuric acids and concluded 
that it was not due to the formation of an oxide film, but 
was a true passivity in the sense of an ennobling (Vered- 
lung) of the metal {Zeit. Elektrochemie, 1903, ix., 454) 
accompanied by a low electrical potential. 

Moody {loc. cit., p. 15) asserts that potassium bichromate 
prevents the formation of rust, owing to the fact that it 
slowly dissolves iron and its hydroxides. He observed 



that the addition of ammonia to solutions of chromic acid 
and its salts which had been allowed to act on iron pro- 
duced precipitates of hydroxide. This point has been care 
fully investigated by the writer, with the following 
results : — Iron which is free from manganese is not 
attacked by solutions of bichromate, even if boiled for days 
in a flask fitted with a return condenser. Manganese is, 
however, readily soluble in bichromate solutions, and 
therefore iron rich in manganese yields a sufficient amount 
to the solvent action to produce a small amount of brownish 
manganese hydroxide when the bichromate solution is 
poured off, made slightly ammoniacal, and allowed to 
stand. If metallic manganese is boiled in bichromate solu- 
tions it dissolves readily, and subsequent addition of 
ammonia produces an abundant precipitate of brown 
manganese hydroxide. 

If polished iron is allowed to stand for some time in 
standard tenth-normal potassium bichromate solution, the 
oxidising strength of the latter as measured by its titration 
value is slightly reduced without the solution of the iron 
or the production of any visible effect. Under the same 
conditions a standard solution of neutral potassium 
chromate is slightly reduced with the appearance of a 
small amount of chromic hydroxide. In fact, all the 
evidence obtainable points to the abstraction by the iron 
of some of the available oxygen of chromic acid and its 
salts without the formation or solution of iron oxide films. 

In order to show beyond doubt that an oxygen electrode 
is formed by immersing iron in a strong solution of bi- 
chromate the following experiment was made: — Two 
polished steel electrodes were prepared and chromated by 
immersion for a number of hours in a strong solution of 
potassium bichromate. The prepared electrodes were 
then thrust tightly through a rubber stopper which closed 
the Jena flask a, which was then filled with pure freshly 
boiled distilled water in the manner shown in Fig. i. 
The electrodes were then attached to the poles of a 
primary battery at about 2 volts potential. At the end of 
half an hour, although the potential was not sufficient to 
disengage bubbles of gas and no visible change had 
occurred, the electrode which was connected to the zinc pole 
of the battery had lost its passivity, the other retaining it. 
It might still be objected that if a film of oxide had been 
formed it might suffer reduction at the negative pole. It 
is, however, very easily shown that electrodes which have 
been oxidised by gentle heating are not reduced under the 
conditions of this experiment. 

Wood [Am. Soc. Mech. Eng. Trans., 1895, xvi., 671) 
in 1895 commented on the power of paints and pigments 
containing certain oxidising agents, notably potassium 
bichromate and lead chromate, to form on iron and steel 
surfaces a thin coating of oxide which so effectually pro- 
tects the metallic surfaces from corrosion that after the 
removal of the paint the metal still resists atmospheric 
effects for a long time, as well as the stronger effect of 
immersion in sea water or acidulated waters and sulphurous 
and other vapours. This action, Wood adds, is very 
obscure and not thoroughly understood ; but the fact 
remains, and extended experiments in this field only 
demonstrate its presence and usefulness. 

The oxide film theory has been held for many years to 
account for the passivity of iron, but in the writer's opinion 
the protection afforded by certain oxidising agents is 
electro-chemical and not mechanical. 
(To be continued). 

Atomic Weight of Silver. — A. Leduc. — Dubreuil has 
recently calculated the atomic weight of silver to be 
107994 taking O = 16, but if O -- 16027 ^he value obtained 
is 107-81, which is considerably lower than 108. He also 
states that the result is more likely to be correct the 
greater the number of methods employed to find it, but it 
should be observed that this is only true if all the methods 
are equally good, and it is actually better to rely upon one 
single method if the others are known to be comparatively 
inaccurate. — Comptes Rendtis, cxlvii., No. 21. 



i8 



Silicon Researches. 



Chemical News 
Jan. 8, 1909 



PROCEEDINGS OF SOCIETIES 

CHEMICAL SOCIETY. 

Ordinary Meeting, December ijth, 1908. 

Sir William Ramsay, K.C.B., F.R.S., President, in 
the Chair. 

Os the question of admitting women to the Fellowship of 
the Chemical Society, the President was desired by the 
Council to make the following statement : — 

As already announced, the recent ballot on this question 
showed that of those among the 2900 Fellows of the 
Society who voted, 1094 were in favour of, 642 opposed 
to, the admission of women to the full rights and privileges 
of Fellowship. Consequent on this difference of opinion 
three considerations presented themselves. 

1. In 1904 the opinion of Counsel was taken as to the 
eligibility of women for Fellowship under the existing 
Charter, and your Council was advised that married 
women are certainly excluded, whilst the position of un- 
married women is extremely doubtful, and that it would 
not be wise to admit women to Fellowship without first 
applying for a Supplemental Charter. Such a course would 
involve the Society in considerable expense unless, as has 
been suggested, the cost were met in part by the petitioners ; 
moreover, your Council was advised on a previous occasion 
when application for a Supplemental Charter with another 
object in view was under discussion, that in the opinion of 
Counsel it was " highly improbable that the Government 
department before whom the application must come would 
be disposed to listen to the application unless it repre- 
sented the practically unanimous vote of the Fellows, and 
that any active opposition by even a small minority would 
probably be fatal " (Proceedings, 1898, p. 38). 

2. Assuming, however, that a successful application for 
a Supplemental Charter were made, and a certificate of 
candidature on behalf of a woman were presented, the 
ballot, if reflecting the above-mentioned figures, would 
result in the rejection of the candidate, because at least 
three-fourths of those voting must be in favour. 

3. Your Council might accord to women the privilege 
of using the Library and attending the meetings, and allow 
them to purchase the publications of the Society at 
approximately cost price. 

After mature deliberation your Council has decided by a 
considerable majority that it would remove some of the 
disabilities experienced by women chemists if the following 
resolution were adopted. 

" That in the opinion of this Council it is desirable that, 
at any time, on recommendation by three Fellows of the 
Society, women be accepted as Subscribers to the Society. 
Such women Subscribers shall pay an annual fee of thirty 
shillings ; they shall be admitted to all ordinary meetings 
of the Society ; they shall have the same use of the Library 
as the Fellows, and they shall be supplied with the Pro- 
ceedings, Transactions, and Annual Reports of the Society 
as these are issued." 

This resolution has now been adopted. 

It was further announced by the President that the 
Society was once more indebted to Sir Henry Roscoe for 
a valuable gift of books, comprising 636 volumes. The 
meeting endorsed with acclamation the vote of thanks 
already accorded Sir Henry by the Council. 

The seventieth birthday of Professor Dr. G. Lunge will 
be celebrated on September 15th, 1909, and a local com- 
mittee has undertaken to arrange a suitable commemora- 
tion of the occasion ; the President stated that those 
Fellows who desire to show their sympathy with the 
festival are requested to communicate with Herrn Dr. E. 
Berl, Zurich IV., Sonneggstragse 84. 



Mr. M. Barrett was formally admitted a Fellow of the 
Society. 

Certificates were read for the first time in favour of 
Messrs. George Henry Joseph Adiam, B.A., 86, South- 
moor Road, Oxford ; Hubert Brunskill, 7, Friarage 
Gardens, Hartlepool ; John Wilberforce Green, 22, Alwyne 
Road, Wimbledon; John Esson McGillvray, M.A., 15, 
Regent Street, Hartlepool ; William Norton Morley, B.Sc, 
325, Brownhill Road, Catford, S.E. ; Frederick Hubert 
Painter, B.Sc, Heatherbank, Alum Chine Road, Bourne- 
mouth ; Colston James Regan, 14, Penerley Road, Catford, 
S.E. ; James Thomas Stevenson, 67, Surrey Street, 
Sheffield. 

Of the following papers, those marked * were tead : — 

•266. "Silicon Researches. Part XI. Silicotetrapyrrole." 
By James Emerson Reynolds. 

Much of the work recorded in former papers of this 
series related to the action of silicon halides on aromatic 
compounds, including the amino-group, or its equivalent, 
as a side-chain. It was shown that well-defined, crystal- 
lised substances could be formed, such as Si(NH"C6H5)4, 
in which silicon was obtained for the first time wholly 
combined with nitrogen. In the course of the study of 
these substances, it became evident that the inquiry should 
be carried a stage or two farther, so as to include com- 
pounds in which nitrogen forms part of a ring, as in pyrrole 
and pyridine. 

Silicon tetrachloride can be added to pure pyrrole with 
little effect, but when some light petroleum is poured in, 
complete mixture is effected and a brown condensation 
product, containing a small and variable proportion of 
silicon, separates out. This feeble action of the free base 
is in strong contrast with the violent interaction of aniline 
and the silicon compound. 

It was found, however, that when potassium pyrrole, 
C4H4NK, was treated with silicon chloride at a low tem- 
perature, energetic action ensued, "potassium chloride arvd 
a crystalline substance, in fine needles, which proved to 
have the composition Si(NC4H4)4, being formed. This 
compound melts at 173° (corr.), but decomposes if heated 
to a materially higher temperature. Its molecular weight, 
as determined by the boiling-point method, agrees with 
the above formula. The substance differs materially from 
silicophenylamide, more especially in the action of heat 
on it. 

*267. " Silicon Researches. Part XII. The Action of 
Silicochlorofortn on Potassium Pyrrole." By James 
Emerson Reynolds. 

As a synthesis of pyridine from pyrrole has been effected 
by the action of ordinary chloroform on potassium pyrrole, 
it seemed possible that silicochlorofprm might yield a 
silicopyridine, that is, a pyridine ring including SiH instead 
of one CH group. 

Violent action occurs when silicochloroform is added to 
potassium pyrrole, and the mass becomes dark brown or 
black, owing to the decomposition of a large proportion of 
the pyrrole, but nothing definite could be extracted from 
the residues of several such experiments save some of the 
tetrapyrrole compound described in Part XI. However, 
when the materials used were cooled to a very low tem- 
perature, the interaction was not so violent, and a small 
quantity of a dark green liquid was extracted, which did 
not boil at 210^^ under a pressure of 50 mm., and decom- 
posed rapidly above that temperature. It proved to consist 
of SiH(NC4H4)3 in a nearly pure condition. When cooled 
in liquid air, it became a deep bronze-green solid, but 
rapidly liquefied at the ordinary temperature. It is very 
easily decomposed in moist air. 

Another compound was obtained during the preparation 
of the tripyrrole derivative ; this is a liquid boiling at about 
i35°/50 mm., and has the composition SiH(NC4H4)Cl2. It 
is easily decomposed by water, and fumes in the air. 
Neither this liquid nor the tripyrrole compound exhibits 
any characters of a silico-nitrogen-carbon ring, but they 



Chemical News, I 
Jan. 8, 1909 ' 



Formation mid Reactions of Imino-compounds. 



promise to prove useful in further attempts to form such 
cyclic combination. 

•268. "Silicon Halides and Pyridine, Acetonttrile, &-€." 
Part XIII. By James Emerson Reynolds. 

It was inferred from the experience obtained with pyrrole 
that organic substances, including nitrogen wholly com- 
bined with carbon, would react feebly, if at all, with silicon 
halides. A series of experiments has confirmed this view 
so far as applies to the compounds used, namely, pyridine, 
acetonitrile, propionitrile, and benzonitrile. 

Pyridine gave with silicon tetrabromide the additive 
compound SiBr4,2C5H5N, and the chloride yielded a similar 
substance, which latter was also obtained by Harden. 
Acetonitrile and propionitrile also gave additive compounds 
of the same order with silicon tetrabromide, and much less 
easily with the chloride, but benzonitrile did not appear to 
combine with either. 

•269. " The Affinity Values of Tropine and its Deriva- 
tives." By Victor Herbert Veley. 

It was shown that tropine, the parent base of the atropine 
and cocaine alkaloids, has a considerably lower affinity 
value than piperidine, and it was concluded that the 
stronger piperidine residue is modified by being conjoined 
to the weaker pyrrolidine residue if the constitution of this 
base proposed by Willstatter is correct. 

Ecgonine, or tropinecarboxylate, possesses all the pro- 
perties of an amphoteric electrolyte ; its nature is in all 
probability that of an inner anhydride or betaine. 

Anhydroecgonine is a stronger base than ecgonine ; the 
affinity value obtained was approximately equal to that of 
a benzenoid betaine. 

Benzoylecgonine in diluta solution does not remain in 
combination with hydrochloric acid ; its basic function is, 
therefore, of the order of caffeine. 

Cocaine is a relatively strong base, although weaker 
than ammonia ; the effect produced by the substitution of 
the carboxylic hydrogen by the methyl group is analogous 
to that previously observed in the case of glycine. 

The affinity value of cocaine was found to be approxi- 
mately ii) = 2'5 10-", by determining the mass of sodium 
hydroxide, contained in a hydrolysed borax solution, which 
was required to upset the equilibrium between a certain 
mass of cocaine combined with hydrochloric acid as a 
dissolved salt. 

The tropeines, atropine and homatropine, have affinity 
values greater than ^6=1 10-'; it appeared that when 
aqueous solutions of their hydrochlorides are heated for 
some time to their boiling-point, no conversion of the 
lactonic group into the corresponding hydroxycarboxylic 
acid takes place. 

*270. " Hydroaromatic Ketones. Part I. Synthesis of 
Trimethylzyc\ohexenone {tsophorone) and some Homo- 
logues." By Arthur William Crossley and Charles 

GiLLING. 

Further investigation of the trimethylc_yc/ohexenone ob- 
tained by the interaction of ethyl malonate and chloro- 
dimethylcjc/ohexenone (Proc, 1908, xxiv., 130) has proved 
it to be identical with isophorone. 

This method for preparing hydroaromatic ketones has 
been extended by using substituted malonic esters, but, 
unfortunately, the yields of the initial condensation pro- 
ducts become smaller with increase in the molecular 
weight of the substituting group. Thus while it has been 
found possible to prepare dimethylethyl- and dimethyl- 
propyl-cyclohexenones, only traces of a condensation pro- 
duct could be isolated from the interaction of chloro- 
dimethyk_)'c/ohexenone and ethyl jsopropylmalonate, and 
the method would not, therefore, appear to be of any 
practical utility for the preparation of the higher members 
of the series. 

*27i. "Note on the Determination of the Rate of 
Chemical Change by Measurement of the Gases Evolved." 
By John Cannell Cain and Frank Nicoll. 

The authors showed that the criticism of iheir work on 



19 



the rate of decomposition of diazobenzene chloride 
advanced by F. E. E. Lamplough in a paper bearing the 
above title and read before the Society in igo6 {Proc, 
xxu., 280 ; compare also Proc, 1908, xxiv., 29), and 
recently published in full {Proc Camb. Phil. Soc, 1908, 
xiv., 580), are invalid for the following reasons :— i. It is 
definitely stated in their paper {Trans., 1902, Ixxxi., 1415) 
that " the flask usually contained pieces of broken glass 
for purposes of adjustment, and was well shaken during 
this operation (of heating the diazo-solution to the required 
temperature) to avoid overheating," and hence super- 
saturation was impossible. 2. The whole of the calcu- 
lated amount of nitrogen was measured ; hence none was 
retained by the solution beyond the minimum quantity 
(which is within the limits of experimental error) ordinal ily 
dissolved. 

Moreover, it was pointed out that Lamplough has over- 
looked Euler's proof that the reaction is accelerated by 
colloidal platinum, for in the experiments on the decom- 
position of hydrogen peroxide the platinum stirrer was 
coated with wax to guard against any possible action of 
the platinum, whilst this precaution was omitted in the 
experiments on diazobenzene chloride. This may well 
account for the higher value of the constants obtained. 
Further, Euler has proved by experiment that no super- 
saturation of the solution with nitrogen takes place in the 
decomposition of the diazo-solution {Annalen, 1902, 
cccxxv,, 295). Finally, the authors expressed the opinion 
that Lamplough's method of measuring the value of con- 
stants which vary enormously with the temperature (being 
multiplied three to four times for a difference of 10°), by 
omitting to carry out his experiments with a thermom.eter 
in the reacting liquid, and by heating the diazo-solution 
"one or two degrees higher than (the temperature of) the 
water-bath," which again would raise the value of the 
constant found, cannot be regarded as an exact one, and 
the conclusion was drawn that the author's determinations 
of the values of the constants in question (in which the 
temperature was carefully maintained at the correct point) 
are to be looked upon as being the most accurate yet 
recorded. 

Discussion. 
Dr. Senter said he did not think that Dr. Cain's solu- 
tion could have been appreciably supersaturated under the 
conditions of experiment. In his experience, however, 
solutions in which gases were generated might become 
highly supersaturated under certain conditions. In the 
course of an attempt to determine the rate of decomposi- 
tion of hydrogen peroxide by highly diluted blood (i of 
blood to 500 of water) by measuring the oxygen liberated 
(compare Zeit. Phys. Chem., 1903, xliv.,257), it was found 
that if the reaction was allowed to proceed quietly for 
some time, and the bottle was then vigorously shaken, an 
immediate increase in the volume of the oxygen, amounting 
to several cc, was observed, although, as shown by sub- 
sequent investigation, the course of the reaction is perfectly 
regular. The amount of oxygen held in solution before 
shaking amounted at least to five times the ordinary solu- 
bility of the gas, and could not be due to chemical com- 
bination with the constituents of the blood — (1) because of 
the exceedingly small proportion of blood present (under 
ordinary conditions blood only takes up about 20 per cent 
of its volume of oxygen at atmospheric pressure) ; (2) 
because the gas was set free by shaking alone. 

The President remarked that certain colloidal and 
albuminous substances have a considerable influence in 
causing their solutions to retain gas in solution : he alludtd 
to the solubility of nitrogen in blood-serum. He under- 
stood from Dr. Senter that the subject is being investigated 
by Dr. Findlay. 

272. " The Formation and Reactions of Imino-compounds. 
Part VII. The Formation of 1 : ^Naphthylenediamine 
from A-Imino-a-cyano-y-phenylpropane." By Stanley 
Robert Best and Jocelyn Field Thorpe. 

In order to study the effect of concentrated sulphuric 
acid on benzenoid imino-nitriles containing no other sub- 



20 



Benzyl Sulphoxide. 



/Chemical News, 
1 Jan. 8, 1909 



stituting groups in the side-chain, attempts were made to 
prepare B-ifnino-a-cyano-y-phenylpropane (i) by the con- 
densation of phenylacetonitrile with acetonitrile, but 
without success. It was ultimately found that this sub- 
stance can be prepared by the action of alcoholic sodium 
ethoxide on ethyl W-imino - a - cyano - y - phenylbutyrate, 
CH2Ph-C(:NH)-CH(CN)-C02Et, which yields, in the first 
instance, B-imino-a-cyano-y-phenylbutyric acid (II.), and 
subsequently, by the elimination of carbon dioxide, the 
above imino-nitrile. Both /9-imino- i-cyano-Yphenylbutyric 
acid and f:J-imino-o-cyano-7-phenylpropane pass into 
naphthalene derivatives on treatment with concentrated 
sulphuric acid, the former into i : 3-naphthylenediamine- 
2-carboxylic acid (HI.) and the latter into i : 3-naphthylene- 
diamine (IV.) : — 



CH2 

./\/'^C:NH 

I 

CN 
I. 

CH2 
\/\ C:NH 

CHCO2H 



/\/\ 



NH, 



NHa 
IV. 



\/\ 



NH2 



CN 



II. 



NH2 
III. 



During the experiments on the conditions of hydrolysis 
of ethyl t^-imino-«-cyano-'y-phenylbutyrate with one equiva- 
lent of alcoholic potash, it was found that when methyl 
alcohol is the solvent used the ethyl salt is completely 
converted into methyl P-imiiio-a-cyano-y-phenvlbutyrate, 
CH2Ph-C(:NH)CH(CN)-C02Me, and that when water 
is present the potassium compound of methyl o-cyano-*)- 
phenylacetoacetate, CH2Ph-C0CK(CN)-C02Me, is the 
sole product. Methyl S-imino-a-cyano-7-phenylbutyrate 
passes into methyl i : ■;i,-naphthylcnediamine-2-carboxylate 
on treatment with sulphuric acid. 

273. "The Absorption Spectra of Para-benzoquinone, 
Qninol, and Qiiinhydrone in the State of Vapour and in 
Solution." By Walter Noel Hartley and Alfred 
Godfrey Gordon Leonard. 

The absorption spectra of /"-benzoquinone and various 
derivatives in solution were examined by Hartley, Dobbie, 
and Lauder (Brit. Assoc. Rep., 1902, p. 107), and com- 
pared with the various structural formulae which had been 
proposed for these substances. The chemical reactions of 
/)-benzoquinone were referred to, particularly its powerful 
oxidising action on alcohols (Ciamician and Silber, Ber., 
190 1, xxxiv., 1350), and therefore alcohol had been regarded 
as an unsuitable solvent. Balyand Stewart (r^-awj., 1906, 
Ixxxix., 506) regard water as an unsatisfactory solvent and 
employ alcohol. They find the curve for />-benzoquinone 
in alcoholic solution to be quite different from that observed 
by Hartley, Dobbie, and Lauder. Experiments made by 
one of the present authors, in 1902, seemed to show that 
both alcoholic and aqueous solutions under the action of 
light yield quinol, and the band of quinol is indicated on 
the curves. To ascertain the absorption spectrum of pure 
/i-benzoquinone, photographs of the absorption spectrum 
of its vapour which had been already obtained were com- 
pared with those of a solution of the substance in a neutral 
solvent, such as ether. The results led to an extension of 
the work to quinol and quinhydrone, in consequence of the 
discovery of a reversible reaction, expressed in terms of the 
following equation : C6H602:Z±C6H402 f H2, when quinol 
vapour is heated in air to 147° at atmospheric pressures 
and exposed to light. When heated in hydrogen, the 
quantity of />-benzoquinone produced is diminished. 
Among the conclusions arrived at are, that ether is the 
only suitable solvent at all concentrations, and that under 



the influence of sunlight, or ultra-violet rays, an inter- 
action occurs between the solvent alcohol and ths solute 
/>-benzoquinone which leads to the reduction of the latter 
to quinol or quinhydrone. 

274. " The Constitution of Para-benzoquinone." By 
Walter Noel Hartley. 

In a previous paper the author has shown how the 
formula for benzene as proposed by Kekule might be 
reconciled with those of Armstrong and von Baeyer(rra«j., 
1905, Ixxxvii., 1823). From the evidence obtained during 
the investigation of /"-benzoquinone, and of benzene and 
its homologues in a state of vapour {Phil. Trans., 1908, 
A, ccw'm., 475), it now appears certain that neither ^-benzo- 
quinone nor quinol has a fixed and settled constitution 
in the strict sense of their usual symbolic representations, 
or the interpretations of them. It has been proved that 
/"-benzoquinone is a benzene derivative, and furthermore, 
that it is possessed of a dual character in the sense that 
the function of the molecule can be either that of a double 
ketone or of a peroxide, according to circumstances. The 
reversible reaction described in the previous paper by Mr. 
Leonard and the author is now under further investigation. 

275. "Benzyl Sulphoxide: A Possible Example of 
Dynamic Isomerism." By John Armstrong Smythe. 

By the action of hydrochloric acid on benzyl sulphoxide, 
four to six of the following compounds are produced : 
benzaldehyde, benzyl chloride, benzyl mercaptan, benzyl 
disulphide, benzyl sulphide, benzyl disulphoxide, and 
benzaldehyde benzyl - mercaptale. The study of this 
reaction under dififerent conditions has shown that it is 
influenced by temperature and the nature of the solvent 
in which it takes place ; the oxygen of the sulphoxide 
passes over chiefly into the disulphoxide in aqueous sol- 
vents, but progressively larger amounts of benzaldehyde 
are formed as the solvent becomes more anhydrous and 
the temperature rises. 

To account for these and allied phenomena, it is assumed 
that benzyl sulphoxide exists in solution in two forms, 
which differ constitutionally in the position of the oxygen 
atom in the molecule. On the basis of this hypothesis, a 
series of equations involving the tautomeric forms is pro- 
posed, which gives a simple and consistent account of the 
formation of all the various products, and enables the 
hypothesis to be tested by comparison of the quantities 
calulated from the equations with those found experi- 
mentally. The agreement of calculated with experimental 
results is held to justify the hypothesis. 

The quantitative data enable further the equilibrium 
between the tautomerides under certain conditions to be 
investigated, and they also show the influence of water as 
catalyst in the conversion of one form into the other. 

Confirmatory evidence of these views is obtained from 
other reactions of benzyl sulphoxide. 

276. " The Chemical Dynamics 0/ the Reactions between 
Sodium Thiosulphate and Organic Halogen Compounds. 
Part III." By Arthur Slator and Douglas Frank 
Twiss. 

The velocities of the reactions between sodium thio- 
sulphate and the following halogen compounds have been 
measured : propyl iodide, isopropyl iodide, allyl iodide, 
chloroacetone, chloroacetophenone, benzyl chloride, o-, />-, 
and tn - nitrobenyl chlorides, ethyl a - bromopropionaie, 
and ethyl o-bromobutyrate. The great activity of the 
acetone derivatives is remarkable. Allyl iodide is more 
reactive than methyl iodide. The activity of the benzyl 
chlorides is of the same order of magnitude as that of 
methyl chloride. The Jio-compounds are less reactive 
than the corresponding normal compounds. 

To explain to a certain extent the results of this and 
other investigations, it is suggested that the halides exist 
in more than one form in solution, and that some reagents 
react with one form and some with another. 

2/7. " Note OH the Optical Rotatory Power 0/ Menthyl 
Cinnamate." By Thomas Percy Hilditch. 

The author's observations on menthyl cinnamate {Trans., 



Chemical News, 



Jan. 



1909 



Heats of Combustion of Aluminium, Calcium, and Magnesium. 21 



1908, xciii., i) showed that his specimen of this ester, 
although identical in most physical properties with those 
described by Tschugaeff [yourn. Ru$s. Phys. Chem. Soc, 
igo2, xxxiv., 606) and Cohen and Whiteley (Trans., 1901, 
Ixxix., 1308), possessed in chloroform solution a widely 
different rotation from that given by Tschugaeff for the 
liquid ester ([n] d —86-65'). 

An opportunity for further investigation of this point has 
been afforded by experiments made primarily with the 
view of ascertaining the degree of accuracy of a polari- 
meter in the University of Jena ; two samples of menthyl 
cinnamate were prepared, one from cinnamic acid procured 
from Kahlbaum, and the other from acid prepared by the 
author from benzaldehyde by Perkin's reaction. The 
menthol possessed a specific rotation \a]T, 15 -48-84° in 
5 per cent chloroform solution. The purification of the 
esters was accomplished, as previously, by two successive 
distillations in a vacuum ; the boiling-point of each sample 
was 210 — 212720 mm. 

In ID per cent chloroform solution the first preparation 
had f n] D 15 - 60-44°, and the second [a] d 15 - 60-50° ; the 
value previously obtained with menthol, [ajo 20 -48-40°, 
was [<i 'd 20 —6000°. On examining the compound without 
a solvent, however, the observed optical activity was 

la]D 15 -85-95° 

It was obviously a matter of great difficulty to deter- 
mine, at the temperature of the experiments, the molecular 
condition of the ester, either undissolved or dissolved in 
chloroform. The rotatory power in glacial acetic acid was 
therefore measured, when a 5 per cent solution gave 
[«]d 15 -60-02°. It may thus be assumed that the 
molecular state of the substance here is the same as in 
chloroform. A molecular-weight determination by the 
freezing-point method in glacial acetic acid solution showed 
the ester to be unimolecular (0-2204 ester in 26804 acetic acid 
gave A = 0-1 13°, whence M.W. = 280-8. Ci9H2602 = 286) ; 
hence the substance is unimolecular in acetic acid and 
also in chloroform solution, whilst in the undissolved state 
it is probably associated. It may be noted that the corre- 
sponding menthyl (3 - phenylpropionate possesses the 
same rotatory power in the fused state as in chloroform 
solution. 

Similar irregularities have been mentioned by Rupe 
{Annalen, 1903, cccxxvii., 164) in the case of menthyl 
acetate, which possesses less activity in alcohol solution 
that when no solvent is used, although all the other 
menthyl fatty acid esters show greater optical activity in 
alcohol than in the absence of solvent, and by Freundier 
(Comptes Rendus, 1893, cxvii., 556; Ann. Chim. Phys., 
1895, (vii-]i Jv., 244), who showed that ethyl alcohol, 
methyl alcohol, and acetone solutions of dipropyl diacetyl- 
tartrate have a weaker rotatory power than the undissolved 
substance, whilst dipropyl dibutyril- and dihexyl-tartrates 
possess stronger activity in these solvents than in the 
undissolved state. 

It follows from the above results that such esters are 
not in the same molecular condition when undissolved as 
when in solution, and that any measurements designed for 
the purpose of comparing the rotatory powers of a series 
of substances should be conducted in circumstances which 
ensure that the compounds in question are present in a 
normal, or, in other words, unimolecular, condition. 

278. "Liberation of Iodine from Hydriodic Acid by 
certain Halogenated Malonyl Derivatives." By Martha 
Annie Whiteley. 

During the continuation of the work on derivatives of 
malonamide (Proc, 1904, xx., 92) and of barbituric acid 
(Trans., 1907, xci., 1330), it has been observed that the 
mono- and dibromo-derivatives of these series, com- 
pounds containing the complex — CO-CHBr-CO — or 
— COCBrz-CO— , hberate iodine from hydriodic acid 
at the ordinary temperature according to the equation 
>CBr2 f 4HI=>CH2-t 2HBr + 2I2. 

In most cases the reaction is complete, and can be em- 
ployed as a method for estimating the bromine in the 
ompounds. Quantitative results have been ob- 



tained with dibromomalonamide, bromomalonyldiurethane, 
(CO-NH-C02Et)2CHBr, m. p. 148°, 5 : 5-dibromo-i : 3- 
diphenylbarbituric acid, s-bromo-^-bemoyl-i : ydiphenyl- 
barbituric acid, Cziiii'iO^lizBx, m. p. i86°, ybromo-i:y 

diphenyl-2-thiobarbituric acid, CS<!^p|j|^Q>CHBr, 

m. p. 220°, and 5 : ^-dibromo-i : ydiphenyl-z-thiobarbi- 

NPh-CO 
tunc acid, CS<j^pj^^Q>CBr2, m. p. 190; and some 

of these compounds react also with silver nitrate in the 
presence of dilute nitric acid, forming silver bromide. 

Dichloromalonamide slowly liberates iodine from 
hydriodic acid at the ordinary temperature, but the re- 
action is not complete even at 100°. 

The replaceability of halogen by hydrogen by the action 
of hydriodic acid at the ordinary temperature has hitherto 
been regarded as a characteristic reaction of compounds 
containing the nitrogen-halogen as distinguished from 
those containing the carbon-halogen linking (Chattaway, 
Trans., 1905, Ixxxvii., 145 ; Chemical News, 1908, 
xcviii., 285); since the results quoted above show that 
this generalisation is no longer tenable, it seemed advisable 
to publish this preliminary statement. The investigation 
is being extended to other compounds containing the 
>CHX or <CX2 group to ascertain to what extent the 
replaceability of the halogen is influenced by the nature of 
the neighbouring groups. 



FARADAY SOCIETY. 
Ordinary Meeting, December isth, 1908. 

Dr. T. M. LowRV in the Chair. 

Dr. F. J. Brislee communicated a paper, which was read 
by Dr. N. T. M. Wilsmore, on "A Re-determination of 
the Electrolytic Potentials of Silver and Thallium." 

The electrolytic potentials of silver and thallium were 
re-determined over a range of concentrations and in solu- 
tions of two different salts — silver in silver nitrate and 
acetate solutions, thallium in thallous nitrate and chloride 
solutions. The measurements were made with a Clark- 
Fisher potentiometer, employing a Weston cadmium cell 
as standard and the decinormal calomel electrode as com- 
parison electrode, the liquid potential at the junction of 
the two being eliminated by a saturated solution of am- 
monium nitrate. The ionic concentrations were calculated 
from the most recent conductivity measurements. All 
measurements were made at room temperature, viz., 
17° C. The results obtained for the electrolytic potentials 
of silver were : — 

Silver in silver nitrate : + 1-076 ^ 0-0005 volt, mean of 
six determinations. 

Silver in silver acetate : + 1-075 + 0-0013 volt, mean of 
six determinations. 

General mean of both series of measurements is : 
+ 1-0757 ^ o-ooo6 volt. 

For thallium the results obtained were : — 

Thallium in thallous nitrate : -0042 ±0-001 volt, mean 
of six determinations. 

Thallium in thallous chloride: —0042 ± 00004 volt, 
mean of four determinations. 

The general mean is : - 00425 + 0-0005 volt. 

Prof. R. Abegg (communicated) expressed the hope 
that English writers would use the symbols proposed by 
the " Potential Committee " of the German Bunsen Society, 
and adopted by the Fifth International Congress of Applied 
Chemistry, when publishing electrochemical work. 

A paper entitled " The Heats of Combustion of Aluminium, 
Calcium, and Magnesium" was read by Mr. Frank E. 
Weston, B.Sc, and Mr. H. Russell Ellis, B.Sc 

The values given for the heats of formation of AI2O3, 
CaO, and MgO by various investigators differ very con- 
siderably. The authors have investigated the reduction of 



22 



Chemical Notices from Foreign Sources. 



', Chemical News 
I Jan. 8, 1909 



the oxides of Al, Ca, and Mg respectively by each of the 
metals Mg, Ca, and Al. From the theory of the greatest 
heat development the oxide with lowest heat formation 
should be reduced by the metals of the other two oxides, 
and so on. The experiments were carried out under 
similar conditions, as far as possible, and quantities of 
from 20 grms. to 50 grms. of the mixture used in all cases. 
The mixtures were made in the following proportions : — 
(1) Al203f4AJ; (2) 2Al + 3CaO; (3) aAl + aMgO; (4) 
3Ca + Al203;(5)Ca + MgO;(6)Mg+CaO;(7)3Mg + Al203. 
It was found that — 

(a) Mg reduces AI2O3— product contained 7-43 per cent 

N as nitride, 071 per cent Al, and 3-87 per 
cent Mg. 

(b) Ca reduces AUO3 — product contained 8 per cent 

free Al. 

(c) Mg easily reduced CaO — product contained 33-65 

per cent Ca3N2, I'ag per cent Ca, and 0*47 per 
cent Mg. 

(d) MgO is not reduced by Al even at a temperature of 

1100° C. 

(e) MgO is slowly reduced by Ca — product contained 

579 per cent N as nitride, 4* 16 per cent Ca, and 

0-58 per cent Mg. 
(/) CaO is partially reduced by Al — product contained 

8-3 per cent Ca, 6-i per cent Al, 0-375 P^r cent N 

as nitride. 
The authors conclude that the heat of combustion of 
Mg is greater than that of Ca, and Ca than that of Al. 
However, the heat of combustion of Mg is not much 
greater than that of Ca. The partial reduction of CaO by 
Al and of MgO by Ca are probably endothermic reactions, 
similar to the reduction of B2O3 by K and Na. The 
authors are of opinion that the reactions described above 
are complicated by the interaction of the hot metals with 
the air, and in order to throw light on this point experi- 
ments are being carried out in vacuo. 

Dr. H. BoRNS said that the question of heats of forma- 
tion could hardly be discussed until the results of experi- 
ments to be made in vacuo were known. 

Mr. H. K. PicARD was able to confirm most of the 
results obtained by the authors. He suggested the re- 
action between alumina and aluminium sulphate as an 
interesting one to study, as it might prove to be a source 
of aluminium. 

Mr. H. R. Ellis adduced reasons for supposing that 
when magnesium was employed the nitrite obtained was 
not, as had been suggested, magnesium nitride, but the 
nitride of the metal reduced. 

Dr. N. T. M. WiLSMORE thought the reactions were too 
complicated to allow of deductions from the heats of 
formation of simple oxides. 

Mr. H. Russell Ellis, B.Sc, then read a paper on 
" The Formation of Graphite by the Interaction of Mag- 
nesium Powder and Carbonates." (See Chemical News, 
vol. xcviii., p. 309). 

A preliminary communication on " Colloidal Barium 
Sulphate " was made by Dr. Ernest Feilmann. (See 
Chemical News, vol. xcviii., p. 310). 

Dr. V. H. Veley (communicated) suggested many 
further lines of investigation, such as the use of other 
colloidal menstrua, the determination of the size of the 
particles, the conditions of precipitation by acids, and 
resolution by alkalis, and so on. It appeared possible 
that every variety, from well-defined crystals to amorphous 
masses of barium sulphate, could be obtained. 

Prof. W. W. Haldane Gee (communicated) agreed 
with the author that here was a case of barium sulphate 
nuclei protected by an organic colloid, and thus producing 
stable colloidal solutions, in accordance with Quincke's 
observations, that if there are three immiscible liquids, 
A, B, and C, B will tend to form a layer separating the 
other two if Tab + Tbc<T ac, T being the respective surface 
tensions. The coating might form an electric " double 
layer," preventing neutralisation of the nucleus by 



oppositely-charged ions. He suggested further extensions 
of the method. 

Dr. G. Senter thought examination of the particles by 
the ultra-microscope would prove instructive. 

Dr. H. BoRNS suggested a possible application of these 
colloidal solutions in the production of uniform reflecting 
surfaces — for photometric purposes, for example. 



CHEMICAL NOTICES FROM FOREIGN 
SOURCES. 



Note. — All degrees of temperature are Centigrkde unless otherwiie 
expressed. 

Comptes Rendus Hebdomadaires des Seances de VAcademie 
des Sciences. Vol. cxivii., No. 21, November 23, 1908. 
Borotungstic Acids. — H. Copaux. — When one part of 
neutral sodium tungstate and one and a-half parts of boric 
acid are treated with boiling water, part of the sodium of 
the tungstate is fixed by the boric acid, and the free 
tungsticacid forms a mixture of sodium metatungstate and 
borotungstate, the concentration of the latter being greater 
the more boric acid there is in the liquid. When the solu- 
tion is allowed to stand a crystalline mass of boric acid and 
sodium polyborates separates, and from the liquid after 
concentration with the addition of some boric acid 
two borotungstic acids can be isolated. One crystal- 
lises in the hexagonal system, and has the formula 
B203.28W03.62H20, and the other forms quadratic 
crystals and its formula is B2O3.24WO3.66H2O. The 
heptametatungstic acid is hexabasic, and is only fairly 
stable. The hexametatungstic acid is rather more soluble 
and much more stable ; it is isomorphic with silicotungstic 
acid, and the double formula of the latter corresponds with 
that of the boron acid, except as regards water of 
constitution. 

Action of Antimony Trichloride on Nickel. Forma- 
tion of NiSb. — Em. Vigouroux. — ^The action of vapours 
of antimony trichloride on powdered nickel at 600° leads to 
the formation of a compound of formula NiSb. It is a 
metallic crystalline powder, reddish violet in colour, and 
non-magnetic. It fuses when heated to 1100°, and begins 
to decompose at 1400°, giving up antimony. It is attacked 
by chlorine and oxygen at a red heat. Sulphur decom- 
poses it before the melting-point is reached. Hydrochloric 
acid has no effect, even when concentrated, nor dilute sul 
phuric acid. Concentrated sulphuric acid acts rapidly 
upon it, and also concentrated nitric acid, especially when 
the temperature is raised. Fusion with alkalis seems to 
have very little effect. 

Preparation of Azo - - Carboxyllic Acids. — P. 
Freundler and M. Sevestre. — A good yield of azo-o- 
carboxyllic acids can be obtained by allowing primary 
aromatic amines to react with o-nitroso acids. Thus, 
o-nitrosobenzoic acid and /j-chloraniline give />-chloro- 
benzene-azo-o-benzoic acid, the yield being 60 per cent, — 
(4)CIC6H4NH2+ ON.C6H4.COOH(2) = 

= H2O + (4)C1C6H4N = N.C6H4.CO2H. 
In order to prepare the o-nitroso-compounds necessary for 
this condensation, it is best to apply Baeyer's method for 
the conversion of aniline into nitroso-benzene ; i.e., the 
oxidation of the amino acids by means of Caro's reagent. 
This method gives a perfectly pure product free from nitro 
derivatives. 

Theory of Preparation of Monomethylamine by 
Solutions of Brominated Acetamide. — Maurice 
Fran9ois. — Hofmann supposed that the action of potash 
on brominated acetamide at 70° takes place in two stages, 
methyl cyanate being first produced with loss of HBr, 
and is then converted into methylamine by potash. 
CH3— CO— NHBr + KOH = KBr + C02 + CH3-HNH3.The 



Chemical News,) 
Jan. 8, 1909 I 



Chemical Notices from Foreign Sources. 



23 



author's experiments, however, show that in the solutions 
of brominated acetamide used for the preparation of mono- 
methylamine for every molecule of acetamide one molecule 
of hypobromous acid exists. The bromine is present only 
as hypobromous acid and in the free state. When such 
solutions are heated in presence of a concentrated alkali, 
monomethylamine is formed as the result of a simple 
oxidation by hypobromous acid in certain conditions of 
temperature and alkalinity. Monomethylamine can readily 
be prepared by the action of potassium hypobromite on 
acetamide. 

Humic Matter in Coal. — O. Boudouard. — The oxida- 
tion of coal in the air gives rise to brown products of an 
acid character, soluble in alkalis, and resembling humic 
compounds. There seems to be a certain relation between 
the coking power of the coal and the proportion of these 
substances present. The author has treated coals of 
various origins with potash in order to extract the humic 
matter, which he has subjected to an elementary analysis. 
In the original paper the results are given of fourteen 
analyses in which the carbon varies from 52 to 67 per cent, 
the hydrogen from 3 to 5 per cent, and the oxygen from 
30 to 44 per cent. When the results of the analyses are 
examined it is found that they fall into four groups, the 
formulae of the humic matter being C18H14O6, CisHisOg, 
C18H14O9, C18H14O11 respectively. 

No. 22, November 30, 1908. 

Chlorides and Oxychlorides of Thorium. — Ed. 
Chauvenet. — The anhydrous chloride of thorium, ThCl4, 
can be prepared conveniently by the action pf phosgene gas 
on the oxide at a red heat. ThOa + 2COCI2 = 2CO2 + ThC^. 
The current of gas must be very slow so that the anhydrous 
chloride may sublime by degrees in the front of the tube in 
which the oxide is heated. The author finds that though 
this compound has been described as not deliquescent it 
combines fairly rapidly with the water vapour of the atmo- 
sphere. When an aqueous solution of the anhydrous 
chloride is evaporated on the water-bath and then in a dry 
atmosphere to constant weight, the hydrated chloride, 
ThC^.yHaO, is obtained. Heating to 120 — 160°, again to 
constant weight, gives the oxychloride, Th(OH)Cl3.H20. 
At about 200°, ThCl4.7H20 is transformed into a com- 
pound intermediate between ThOCla and ThOHCls, and 
at 250° in a current of hydrogen chloride gas the hydrated 
chloride loses half its chlorine and gives the anhydrous 
compound ThOCU- 

Action of Antimony Trichloride on Cobalt and its 
Alloys with Antimony. — F. Ducelliez. — Powdered 
cobalt decomposes antimony trichloride at 700°, at 800'' 
the compound CoSb being formed. The alloys of cobalt 
and antimony can be divided into three classes : — i. Those 
containing less than 67-04 per cent of antimony. These 
give crystals of CoSb when treated with hydrochloric or 
sulphuric acid. 2. Those containing from 67-04 to 80-27 
per cent of antimony. These are readily decomposed on 
heating, and give the compound CoSb when kept at 1200° 
in a current of hydrogen. 3. Those containing more than 
80-27 per cent of antimony. These yield the antimonide, 
CoSb2, when treated with nitric and hydrochloric acids. 
The two substances CoSb and CoSba are the only 
compounds which exist among the alloys of cobalt and 
antimony. Chemical reagents have similar effects on the 
two compounds, e.g., when heated in chlorine heat is dis- 
engaged and antimony trichloride distils. With oxygen 
incandescence is observed, and antimony oxide is formed. 
Sulphur attacks them violently. Dilute or concentrated 
nitric acid dissolves the cobalt, and leaves a deposit of 
antimonic anhydride. Aqua regia entirely dissolves them, 
but alkalis and alkaline carbonates when fused with them 
attack them only with difficulty. 

Uranium Disilicide, SiaUr. — Ed. Defacqz.— By the 
aluminothermic method, which may be applied to the 
oxides of tungsten and molybdenum to prepare the 
silicides from them, uranium silicide SijUr can be prepared. 



It is a grey metallic powder of density 8 at o''\ Chlorine 
decomposes it at 500° giving the corresponding chlorides. 
It is soluble in hydrofluoric acid, insoluble in nitric acid, 
hydrochloric acid, sulphuric acid, and aqua regia. It is 
not readily oxidised, and is unaltered in air even at a red 
heat. Mixtures of alkaline nitrate and carbonate attack it 
only slightly at their melting-point, but at a red heat fused 
alkalis and alkaline carbonates convert it into alkaline 
silicate and uranate. Potassium bisulphate acts on it 
slowly at temperatures above its melting-point. 

Hydrogenation of Triphenylmethane. Tricyclo- 
hexylmethanc. — Marcel Godchot. — Triphenylmethane 
can be hydrogenated by leading its vapour over a catalysing 
metal at a suitable temperature by means of a current of 
hydrogen. The product of hydrogenation is tricyclo- 
hexylmethane, (C6Hii)3^CH. It is a colourless liquid 
with an aromatic smell. It boils at 140° under 20 mm., 
and its density at 18° is 08406. It is insoluble in water, 
slightly soluble in alcohol and acetic acid, dissolves readily 
in ordinary ether and benzine. Its solutions are not 
fluorescent. It gives a brown coloration with hot con- 
centrated sulphuric acid, and with bromine yields a 
brominated derivative. 

No. 23, December 7, 1908. 
This number contains no chemical matter. 



Berichte der Deutschen Chemischen Gesellschaft. 
Vol. xli, No. 16, igo8. 
Methyl and Ethyl Ester of Thiophosphoric Acid. 
— P. Pitschimuka. — When phosphorus sulphochloride acts 
on alcohols the chloranhydride of the corresponding acid 
is obtained, SPCI3 + R(OH) = HCl + SPCUCOR). The acid 
chlorides are colourless liquids which cannot be distilled at 
ordinary pressures, and which are not decomposed by 
alcohols and water. With sodium alcoholate they give 
neutral esters of thiophosphoric acid. By the action of 
PSCI3 on solutions of sodium alcoholate in methyl and 
ethyl alcohol, the esters SP(OCH3)3 and SP(OC2H5)3 
were obtained. They readily form complex com- 
pounds, e.g., SP(OCH3)3.2HgCl2, 3SP(OCH3)3.2FeCl3, 
PSO(HgCl)(OC2H5)2.HgCl2, which possess an interesting 
property. Thus, on heating SP(OCH3)3.2HgCl2 to 103°, 
it gives up two molecules of CH3CI, and a salt-like sub- 
stance remains behind, — 

SP(OCH3)3.2HgCl2— 2CH3CI = PS(OCH3)02Hg2Cl2. 

A similar compound, PS03CH3(T1C12)2, is obtained with 
thallium chloride. The methyl ester reacts at the ordinary 
temperature with sodium methylate, yielding the salt 
PSONa(OCH3)2, from which the compound PSOAg(OCH3)2 
can be prepared by the addition of silver nitrate. This 
same compound is obtained by mixing an alcoholic or 
ethereal solution of silver nitrate with the methyl ester, 
the other product of the reaction being methyl nitrate, 
SP(OCH3)3+AgN03-PSOAg(OCH3)2+CH3.N03. Similar 
reactions occur between silver nitrate and the ethyl ester, 
and the ester and sodium ethylate. In the compound 
PSOAg(OCH3)2 the metal can be bound to the phosphorus 
either by means of oxygen or by means of sulphur ; since, 
by converting the compound into esters, thiophosphoric 
acid derivatives are obtained, there can be no doubt 
that the constitution is represented by the formula 
OP(SAg)(OCH3)2. 

Indicator suitable for Use with Hundredth-normal 
Alkali Solution.— E. Rupp and R. Loose.— The authors 
have found that a compound, to which they have given the 
name methyl-red, is exceedingly sensitive towards alkalis, 
surpassing haematoxylin ; it . may be used in place of 
iodoeosin. It is pale yellow in alkaline and neutral solu- 
tion and red-violet in acids. It is prepared by dissolving 
amidobenzoic acid in alcohol, adding concentrated hydro- 
chloric acid, diazotising with sodium nitrite, and adding 
freshly distilled dimethyl aniline. The mixture is then 



M 



Meetings for the Week. 



Chemical Kews, 
I Jan. 8. igog 






[I 



P^.OH. p„0H2 
'"°.0H. (NH3)3j 



1(S04 



heated for half-an-hour on the water-bath, the compound 
is separated off from the solution, treated with hot glacial 
acetic acid, and water is added to the boiling liquid 
till a turbidity is produced. On cooling, the methyl-red 
separates out in glittering violet needles. A 2 per cent 
alcoholic solution is used for the indicator. The compound 
appears to be an azo-compound of o-amidobenzoic acid 
and dimethylaniline. 

Conversion of Hexamminetrioldicobaltic Salts into 
Octamminedioldicobaltic Salts. — A. Werner. — By 
treating hexamminediol sulphate with semi-dilute nitric 
acid a dinitrato-nitrate is formed : — 

,N,3-".OH.-"rN°H3)3]"'°^''- 
This salt is hydrated very rapidly in aqueous solution, and 
then reagents precipitate salts of the nitratoaquohexam- 
minedioldicobaltic series : — 

rOsN p^.OH. p„0H2 "1^ 

The first nitrate does not belong to the latter series, for in 
aqueous solution it has a neutral reaction, while the salts 
of the aquo series, like all aquocobaltic salts, are acid. 
When the aqueous solution of the nitrate is allowed to 
stand for a long time on addition of a soluble sulphate, 
difficultly soluble diaquohexamminedioldicobaltic sulphate 
separates 

■H2O 

.(H3N)3 

The dinitratohexamminedioldicobaltic nitrate takes up two 
molecules of NH3 in liquid ammonia, and gives a good 
yield of octamminedioldicobaltic nitrate : — 

[K^U C°:Sg: CoP^)J(N03)a+2NH3 = 

= [ (H3N)4Co ;°g; Co(NH3)4 ] (N03)4. 

The octamminediol-salt was obtained pure in the form of 
bromide. 

Decammine-/i-amino-dicobaltic Salts. — A. Werner. 
— Octammine-yu-amino-o/-dicobaltic nitrate gives with nitric 
acid a nitrato-aquo-compound, which is converted into 
decammine-/i-aminodicobaltic nitrate in liquid ammonia. 
From the nitrate other salts of the same series can be 
obtained. They all crystallise well, and are red 
in colour. The constitutional formula appears to be 
Cl2[(H3N)5Co— NH2 . . . Co(NH3)5|Cl3. These decam- 
niine salts show a remarkable resemblance in colour, and 
the way in which they separate from their solutions to the 

rhodochromium salts, Cr2 Xrr ^'''° Xj. 

Perchromates. — E. H. Riesenfeld. — The higher oxida- 
tion products of chromium can be divided into two classes : 
— ^(i) Chromium textroxide derivatives, (2) the perchromates 
proper, which include the salts of perchromic acid HCrOs 
(chromium pentaperacid), " blue perchromates," and the 
salts of perchromic acid H3Cr08 (chromium octoperacid), 
" red perchromates." The determination of the molecular 
weight of red potassium and ammonium perchromates 
shows that they are monomolecular, and probably the free 
acid also has the simple molecular weight. By deter- 
mining the electro-chemical equivalent of chromium in the 
red perchromates, it was shown that the chromium was 
not hexavalent, and an argument against the hexavalcncy 
of chromium in the perchromates is provided by the fact 
that as long as potassium is taken to be mono- and oxygen 
divalent constitutional formulae of the perchromates can 
only be constructed on the assumption that chromium has 
an odd valency. The comparison of the peroxide of 
chromium with those of the other elements shows that the 
oxygen is not electro-chemically monovalent; chromium 
peroxide is an antozonide like the peroxides of the alkalis 
and alkaline earths. From experiments on the action of 



perchromate on permanganate it appears that both in the 
red and blue perchromates chromium is heptavalent, the 
formula of the octoperacid being — 

/OOH 

02=Cr<-OOH. 

\00H 

Bismuth Carbonates and Oxalates. — L. Vanino and 
Emilie Zumbusch. — From a bismuth mannite solution 
potassium and ammonium carbonate precipitate a carbonate 
of formula BiO.CO3.BiO. When a clear concentrated 
solution of bismuth nitrate is poured into excess of sodium 
carbonate solution, a precipitate is obtained of composition 
561203. Bi2(C03)3 if washing is continued till all traces of 
nitric acid have been removed. If the precipitate is not so 
thoroughly washed the results of the analysis point to 
the formula BiO.CO3.BiO. A precipitate of oxalate is 
obtained when oxalic acid solution is added to bismuth 
mannite solution. The formula of the oxalate precipitate 

/-vrr 

is Bi2(C204)3 or Bi<p q , according to the experimental 
conditions, both salts being very sensitive towards water. 



MISCELLANEOUS. 



American Philosophical Society. — General 
Meeting, April 22 — 24, 1909. — The American Philo- 
sophical Societyi has satisfactorily shown that the interests 
of useful knowledge in the United States are greatly pro- 
moted by the annual General Meetings of the Society. 
These meetings have proved attractive to its members in 
all parts of the country, not only because of the general 
interest in the scientific communications offered, but also 
because of the opportunities afforded of renewing and 
extending acquaintanceship among workers in the various 
fields of knowledge, and they have markedly broadened 
the field of usefulness of this the oldest scientific Society 
in America. The General Meeting of 1909 will be held at 
Philadelphia on April 22nd to 24th, beginning at 2 p.m. on 
Thursday, April 22nd. The evening of Friday, April 23rd, 
will be devoted to addresses in commemoration of the 
centenary of the birth of Charles Darwin and the fiftieth 
anniversary of the publication of " Origin of Species." 
Members desiring to present papers, either for themselves 
or others, are requested to send to the Secretaries, at as 
early a date as practicable, and not later than March 24, 
1909, the titles of these papers, so that they may be 
announced on the programme which will be issued im- 
mediately thereafter, and which will give in detail the 
arrangements for the meeting. Papers in any department 
of research come within the scope of the Society, which, 
as its name indicates, embraces the whole field of useful 
knowledge. The Publication Committee, under the rules 
of the Society, will arrange for the immediate publication 
of the papers presented. The activity of the Society is 
reflected in the increasing volume of its publications, which 
constitute a series covering one hundred and forty years, 
and include Transactions in quarto and Proceedings in 
octavo form ; its exchange list embraces most of the 
scientific societies of the world. The Society thus ofifers 
valuable avenues of prompt publication and wide circulation 
of the papers read before it. 



MEETINGS FOR THE WEEK, 



Wednesday 13th. -Royal Society of Arts, 5. (Juvenile Lecture). 
" Digging for Ancient Art Treasures," by Cbas. 
WaldBtein. 

Society of Public Analysts, 8. "Analysis of 

Complex Candle Mixtures" and " Detection and 
Estimation of Mercury in Nitro-explosives," by 
O. Hehner. 



Chemical News, 1 
Jan. 15, igog f 



Tantalum, Niobium, and Titanium. 



25 



THE CHE MICAL NEWS 



Vol XCIX., No. 2564. 



TANTALUM, NIOBIUM, AND TITANIUM : 
Observations on. 

Part II. — On the Opening-up oi- Minerals containing 
THESE Bodies. 

By W. B. GILES, F.I.C. 
(Continued from p. 4). 

In smaller quantities I obtained tantalites and columbites 
from Finland, Sweden, Norway, Bavaria, Dakota, New 
Hampshire, Alabama, and other localities. It is curious 
that none of these minerals exhibit any sign of magnetic 
properties. When brought near to the poles of a powerful 
electro-magnetic they are not at all affected, even in a 
state of fine powder, while many titanium compounds, such 
as ilmenite, are, as is well known, decidedly attracted. 
The minerals were first broken up into coarse pieces in a 
small stone breaker ; it was then seen, especially in the 
case of the Middleton columbite, that though the lumps of 
the material appeared to be very free from foreign matter, 
when they were crushed they disclosed thin inclusions of 
mica and other silicates. These were picked out as much 
as possible, and the minerals were then ground so that 
they would pass a loo-mesh sieve. Several kilogrms. of 
columbite and tantalite were prepared in this manner so as 
to form standards. In my first trials to remove the tin 
(which is so troublesome to deal with subsequently) I tried 
fusing the powdered minerals with cyanide of potassium. 
This was not at all satisfactory ; at a low red heat a large 
amount of insoluble potassium tantalate and niobate was 
formed which enveloped the reduced tin so that it did not 
collect in globules. When the fusion was extracted with 
water there was left a porous mass which yielded up tin to 
hydrochloric acid, but a decided amount of the acids also 
went into solution. It is difficult to obtain crucibles or 
vessels of any size that will withstand the action of cyanide 
of potassium at a full red heat without being attacked. 
Knowing that alkaline tantalites and niobates soluble in 
water can only be obtained by using high temperatures in 
the fusion with caustic alkali, I next tried attacking the 
minerals with potassium carbonate at a high temperature 
in nickel and iron crucibles. This plan was successful to 
a certain extent, but the nickel and iron crucibles were 
seriously affected and scaled, externally by the action of 
the air, and internally by the manganate which was formed 
in the fusion. It then occurred to me that if the materials 
were heated at a high temperature in wrought-iron or steel 
vessels in a reducing atmosphere, not only would these 
difficulties disappear but that also one might expect to 
reduce all the tin, lead, antimony, &c., to the metallic 
state at the same time, and thus much trouble and 
uncertainty would be saved in the subsequent operations. 
When this plan was tried it more than answered my 
expectations, for while the tin, antimony, &c., appeared 
to be completely reduced, the iron and manganese were 
obtained as protoxides in the form of a black heavy crystal- 
line sand which could be very easily separated from the 
soluble alkaline tantalate and niobate by treating with 
water. I also found that the zirconia which some of these 
minerals contain was separated apparently almost quanti- 
tatively when the washed crystalline protoxides were dis- 
solved in dilute acids. In the first experiments small steel 
crucibles and covers " spun " in the lathe from sheet-metal 
were made use of, and these answer very well for quantities 
of mineral up to about 25 grms. These crucibles are 
2i inches high, 2\ inches broad at the top, and i^ inches 
across the bottom. They are furnished with well-fitting 
covers which overhang the top of the crucible about three- | 



eighths of an inch. These crucibles are placed in a large 
fireclay or, preferably, in a plumbago crucible, and the 
space between them is packed round nearly to the top of 
the smaller crucible with wood charcoal in fine powder 
well rammed down. The remaining space is filled up with 
lumps of charcoal about the size of nuts, so that the 
exterior lid will just go on. The accompanying figure 
shows the arrangement. 




— C 



A, The exterior crucible ; 11, the space filled with finely-powdered 
charcoal ; c, the steel crucible and contents ; d, the nut-hke piece 
of charcoal. 

The crucible is put into the furnace and slowly brought 
up to a red heat to partially frit the materials, and to allow 
much of the carbonic acid to escape while the mass is still 
porous. The heat is then raised, and maintained at the 
highest temperature the furnace will give for one hour. I 
use one of Griffin's excellent radial burner gas furnaces 
which yield a temperature equal to the fusion of cast-iron 
without any blast of air being required. The exterior 
vessel for the size of the small steel pots mentioned is a 
No. 4 Morgan's plumbago crucible. Recently I have pro- 
cured sorne much larger steel pots and covers which are 
7 inches high by 5^ inches diameter ; these are pressed by 
hydraulic power out of steel one-eighth inch thick, and 
were made for me by Mr. McNeil, of the Kinning Park 
Ironworks, Glasgow. They require a No. 30 plumbago 
exterior crucible, and will deal with about a kilogrm. of 
material at a time. When the crucible is opened after the 
fusion the contents generally come out in one fused com- 
pact piece without any trouble ; the top portion has a yellow- 
white colour, while the bottom layer forms a black mass 
which can often be separated almost completely from the 
top one by a blow with a hammer. If the columbite or 
tantalite contains tin, as is almost invariably the case, the 
interior of the steel crucible is tinned over. Some of the 
tin is frequently found as a spongy metallic mass mixed 
with the black material, and often distinct globules and 
beads are noticed. The whole contents of the crucible 
slightly broken up in a mortar are now treated with about 
500 cc. of water (for 25 grms. of the mineral) when the 
potassium tantalate and niobate pass rapidly into solution 
as they are very soluble, while the heavy black sand-like 
material mixed with a little tin, &c., settles down almost 
immediately, occupying very little space ; above this there 
is a small amount of light green coloured precipitate which 
quickly turns brown in contact with the air. By leaving 
the whole quietly in a tall beaker for an hour about nine- 
tenths of the yellow liquid can be drawn off quite bright 
and clear, thus saving the trouble of filtering it. The 
remainder is stirred up with water, and leaving all the 
heavy material in the beaker the solution is filtered (best 
by the pump and the use of a toughened filter) till all the 
soluble matter is extracted. The small amount of precipi- 
tate on the filter is washed back on to the black sand in 
the beaker. The solution containing the potassium tanta- 
late and niobate is always yellow or brown coloured, and 
contains traces of iron and manganese, probably as double 
potassium carbonates ; this, however, does not afford any 
hindrance to the separation of the tantalic and niobic acids 
in a pure state. Under this rather severe treatment the 



26 



Tantalum, Niobmm, and Titanium. 



' ChemIcAl News, 
I Jan. 15, 1909 



Steel crucibles are not appreciably affected. I have made 
five or six successive fusions of 25 grms. of columbite in 
one of these small spun vessels without noticing any 
change except that the interior became rather heavily 
coated with tin. When this occurs it is well to discard 
them as they are so cheap rather than to run the risk of 
losing the contents. It does not appear to be necessary 
when working upon ordinary columbites and tantalites to 
add any reducing material to the contents of the crucible. 
With some of the stanno- or stibio-tantalites which con- 
tain much tin or antimony it maybe advisable to add some 
black flux prepared from cream of tartar or similar material 
to the mixture. The minerals in this manner are resolved 
into two parts; — 

A. A clear solution more or less yellow or brown 
coloured which contains nearly all the tantalic and niobic 
acids mixed with traces of iron and manganese, but free 
from tin, antimony, lead, or other heavy metals. 

B. A residue of black crystalline sandy matter con- 
taining nearly all the iron, manganese, and other bases 
mixed with some of the metals reducible by carbonic oxide 
or by the protoxides of iron and manganese, though most 
of these metals alloy and unite with the walls of the steel 
crucibles, especially when these are used for the first few 
times. 

A. The solution is treated as follows : — When 25 
grms. of mineral have been employed it will measure with 
the washings about i litre ; to this is added a few cc. (four 
or five ?) of potassium sulphide solution, and the whole well 
stirred up ; this causes the liquid to become black. Rather 
more than enough pure hydrochloric acid than is equivalent 
to the potassium carbonate employed (Soto 100 cc.) is diluted 
with hot water to about a litre, and into this contained in a 
beaker holding 3 to 4 litres the black solution is poured 
with constant stirring. This causes a violent evolution of 
carbonic and sulphydric acids, and the tantalic and niobic 
acids separate out as a white flocculent precipitate. The 
beaker is then placed in a water-bath and heated until the 
precipitated acids appear to settle, then allowed to cool, and 
the clear portion, which should be about five-sevenths of the 
whole, is drawn off with a syphon, and the acids repeatedly 
stirred up with hot water, and washed by decantation till 
ths last washings show no sign of chlorine with silver solu- 
tion. The niobic and tantalic acids generally settle very 
quickly when thus treated, but occasionally they require a 
rather prolonged heating in the water-bath to make them 
do so. I have not been able to find out the cause of this ; 
I have had two successive fusions treated exactly in the 
same way behave differently ; one would settle quite easily 
even with cold water, while the other required considerable 
heating to make it do so. It does not save any time to 
try to filter these acids and so hasten the operation (at 
least with ordinary filters). The water passes through the 
filters readily enough, but it does not wash out the salts. 
Large cracks form, through which the wash-water runs 
unchanged. When the decanted wash-waters cease to 
contain any chloride the acids are brought upon a filter, 
dried at 100° C, and then pulverised. They then yield a 
pure white soft powder resembling oxide of zinc or 
magnesia. They contain no sulphuric acid, chlorine, or 
potassium, no iron, manganese, tin, or heavy metals, and 
as they dissolve almost immediately in cold hydrofluoric 
acid, oxalic acid, &c., they are in a condition eminently 
adapted for their separation by Marignac's process. The 
acids so obtained from the columbite from Middleton when 
dried at 100'' C. gave, on strong ignition, go7i per cent 
of anhydrous acids and 9-29 per cent of water. When 
washing the precipitated tantalic and niobic acids by 
decantation, the supernatant fluid is always opalescent, 
and in order to see what loss this may occasion, and also 
to ascertain how much iron and manganese were present 
in the yellow fluid from 20 grms. of columbite, I evaporated 
the whole amount of the washings to dryness in a platinum 
dish with a slight excess of sulphuric acid, on taking up 
with water and boiling, there was obtained o 038 of ignited 
acids equal to 019 per cent on the columbite. In the 



filtrate from this there was obtained 0-182 grm. of ferric 
oxide and 0-051 of manganese oxide, consequently the 
whole of the filtrates from 20 grms. of the Middleton 
columbite yielded from about 15 to 20 litres of washings : — 

Tantalic-niobic acids 0-038 

Ferric oxide 0-182 

Manganese oxide 0-051 



Total 0-271 grm. 

So that if the object is merely the preparation of 
tantalic and niobic acids, it would obviously never pay to 
deal with these filtrates, but it shows how slight the 
solubility of the acids is in the small excess of hydrochloric 
acid employed, and also how small an amount of iron is 
really contained in the yellow or brown alkaline solutions. 
By this process I have not at present been able to trace 
with certainty the small amount of tungstic acid (026 per 
cent) which is said to exist in this Middleton columbite by 
Herrnann, though in other analyses of this mineral it is 
not indicated. In oider to ascertain what amount of 
carbonate of potassium is necessary I have made a good 
many trials with different proportions with columbites and 
tantalites ; four parts of carbonate to one of mineral gave 
no better results than 3 to i. Three parts of carbonate 
gave a slightly better yield than 2 to 1, and finally I found 
2| to I was as good as 3 to i ; so for ordmary columbites 
and tantalites these are the proportions I generally employ. 

B. The black sandy matter which is left on treating 
the fusions with water is a mixture of ferrous oxide, 
manganous oxide, reduced iron, small globules of tin, 
zirconia, silica, &c. It oxidises rapidly on exposure to the 
air, and so it is advisable to wash it as speedily as possible 
from the alkaline tantalate and niobate, or ochreous pre- 
cipitates form which pass the filters. It is treated with 
hydrochloric acid diluted with its own volume of water, 
when all the black sand like matter dissolves at once, 
leaving some white residue undissolved. Generally there 
seems to be a little metallic iron present, since after the 
black matter has dissolved small particles are seen dis- 
solving with strong evolution of hydrogen. The tin also 
is alloyed with iron, for it is very little attacked even by 
strong acid (Lassaigne, " Gmelin's Chem.," v., 314). As 
it is heavier than the white residue it is possible to separate 
it entirely from this by elutriation. The acid liquid, in- 
cluding the white matter, is then evaporated to dryness in 
a porcelain or glass basin and taken up with dilute hydro- 
chloric acid, the insoluble matter is collected on a filter, 
washed, dried, and ignited. This material is yellowish 
white in colour. It varies in amount from different 
minerals and also somewhat with the temperature reached 
and the amount of potassium carbonate employed. In the 
case of the Middleton columbite it ranged from 5 to 7 per 
cent on the weight of the mineral started with, but about 
half of this was silica. 1-420 grms. of ignited residue 
treated with hydrofluoric and sulphuric acid, gave — 

Matter insoluble in HF and II2SO4 0-7195 
Silica volatilised 0-7005 



Total 1-4200 

The material freed from siiica was fused in a small 
platinum crucible at the highest temperature that could be 
obtained with a powerful blast lamp with an excess of 
pbtassium carbonate. Though the fusion was maintained 
for a long time and the carbonate volatilised rather freely, 
a considerable amount of the material would not dissolve 
but floated about in the fused carbonate. The fused mass 
was digested in water, when a heavy white precipitate re- 
mained undissolved ; this was filtered off, washed, and 
treated with hydrochloric acid, which left it apparently 
unchanged. It was again filtered off, washed, dried, and 
ignited, when it weighed 0-310 grm. This was fused with 
sodium pyrosulphate, when it went entirely into solution 
and dissolved clear in water. This solution gave no sign 
at all of titanium with peroxide of hydrogen. It gave a 



C HEMIC A I. News, 1 
Jan. 15, lox) 1 



Tantalum, Niobium, and Titanium. 



27 



heavy gelatinous precipitate with ammonia which was 
readily soluble in excess of oxalic acid. The solution 
acidified wilh hydrochloric acid gave a very strong orange- 
red colour with turmeric paper, from which it may be 
inferred that the bulk at least of the material was zircoiiia. 
If this is all zirconia it would amount to i"5i per cent on 
the columbite. The matter which was brought into solu- 
tion on the fusion with potassium carbonate was found to 
be a mixture of tantalic acid, niobic acid, and a little 
titanic acid ; it amounted to o'4og5 grm., equal to 2-047 
per cent on the mineral employed. Consequently the 
insoluble matter in this case was composed of: — 

Tantalic, niobic, titanic acids . . . . o'4og5 

Zirconia (?) 0-3100 

Silica 0-7005 



Total 1-4200 

The amount of pure white acids obtained was equal to 
69-32 per cent of the anhydrides, and adding the 0-2 per 
cent in the wash-waters and the impure acid obtained 
from the insoluble matter, the total is 76-62 per cent on 
the mineral employed, which except for the silica agrees 
well with Chandler's analysis for Middleton columbite as 
given for comparison underneath : — 

Niobic-tantalic acid 76-79 

Stannic acid o-6o 

Protoxide of iron 18-23 

Protoxide of manganese 3-14 

Oxide of copper 0-48 

Undetermined 0-76 



The resistance which zirconia offers when fused with 
potassium carbonate is so remarkable that it seems to 
afford a means of separating it from other bodies. To test 
this insolubility directly, I fused i grm. of (so-called) 
chemically pure zirconium hydrate with 4 grms. of potas- 
sium carbonate for an hour at the highest temperature 
obtainable with a gas blast-lamp. On treating the fused 
material with water the aqueous solution was made slightly 
acid with hydrochloric acid, and ammonia then added in 
slight excess. No precipitate resulted. The insoluble 
zirconia was then gently boiled for four hours with hydro- 
chloric acid and water in equal parts, keeping up the water 
from time to time. When this solution was filtered and a 
slight excess of ammonia added, there was a slight turbidity 
which in some hours deposited a few flocks of precipitate. 
These would certainly not weigh more than a milligrm. or 
two. Considering how exceedingly difficult it is to prepare 
really pure zirconia, it is even doubtful whether this trace 
of precipitate was really zirconia. On looking up the 
literature of zirconia, I found that Venables and Clark 
(Chemical News, Ixxiv., 43) in their study on the 
zirconates had previously arrived at the same conclusions. 
It is possible that this insolubility of zirconia may be 
utilised in the very difficult problem of its separation from 
titanic acid ; it certainly seems to answer in this respect 
with tantalic and niobic acids. 

To recapitulate, I have endeavoured to show — (i) That it 
is more profitable to dissolve away the tantalic and niobic 
acid in tantalites and columbites by the action of potassium 
carbonate at a high temperature than it is to reverse the 
process, and to dissolve away the bases from the acids 
with potassium or sodium pyrosulphates. 

(2) That by working in this manner in a reducing atmo- 
sphere, platinum vessels can be replaced by steel crucibles 
with advantage, and also that such metals as tin, &c., are 
by this means effectually removed in the first operation 
instead of requiring continual tedious and uncertain 
re-fusions with alkaline sulphides. 

(3) That any zirconia appears to remain entirely with the 
small portion of insoluble matter left after the fusion has 
been treated with acid, whereas when potassium pyrosul- 
phate is employed, it is dissolved and is likely to be con- 
founded with the acids as Chandler states. Of course it 



is not put forward as a quantitative process, but it certainly 
yields acids which are much purer than those obtained by 
fusions with bisulphates. Since the tin and similar 
metals unite in great part with the vessels used, it is im- 
possible to estimate them even approximately. When it is 
desired to do this, I proceed as follows : — Fuse the finely 
powdered mineral in a platinum crucible at a high tem- 
perature with three parts of pure potassium carbonate, 
extract all that will dissolve by digestion with a solution of 
citric acid at a gentle heat, filter and collect any in- 
soluble matter on a filter, wash well, dry, and ignite it, 
then re-fuse it again with a smaller quantity of potassium 
carbonate, and treat again with citric acid solution. 
Everything now goes into solution except a little silica, 
zirconia, &c., which is filtered off, washed, and kept if 
necessary for further examination. Through the clear 
warm acid solution (which can be supersaturated with 
ammonia without causing any precipitation) hydric sulphide 
is passed to saturation, when the tin, antimony, &c., come 
down as sulphides. (By dissolving very small amounts of 
pure stannic and antimonious oxides in a large excess of 
citric acid, I could not trace that the presence of this acid 
impedes the precipitation). Filtering off the sulphides 
after washing, the solution, now free from heavy metals, 
can be used for the estimation of the tantalic and niobic 
acids as well as for the bases after the destruction of the 
citric acid. 

With regard to the estimation of niobic acid in company 
with tantalic acid, I mentioned in a former paper (Chemical 
News, xcv., i) some peculiarities observed when these 
acids are brought into solution with oxalic acid or oxalates. 
I have spent much time in endeavouring to utilise these 
reactions as a means for their separation, but I regret to 
say without any useful result. When they are associated 
the acids do not behave in the same manner as they do 
separately. At the time this prior paper was written, I 
was unaware that Russ (Zeit. Anorg. Chem., xxxi., 42) 
had previously studied these oxalates, but he too comes 
to the conclusion that " The separation of tantalum and 
niobium by means of the complex oxalates cannot be 
effected." In my previous paper I also mentioned that I 
found that the hydrated tantalic and niobic acids can be 
brought into solution ■icith phosphoric acid, and I showed 
that when such solutions were treated with zinc dust the 
niobic acid yielded intensely brown or black solutions. I 
have since noticed that these deeply coloured solutions are 
very much more permanent than those obtained with 
oxalic or other acids, and I have endeavoured to estimate 
the niobic acid by filtering the solutions in phosphoric acid 
through a column of zinc dust or spongy electrolytic zinc, 
receiving the deeply coloured niobous phosphate in a solu- 
tion of ferric sulphate, in which the reduced iron is after- 
wards estimated by permanganate. Some difficulties in 
the manipulation of this process have been encountered, 
but an apparatus has been recently contrived by which the 
solutions can be digested with the zinc as long as may be 
desired, and finally filtered without any exposure to the 
air. When these experiments are concluded I hope in a 
further article to give an account of them. I believe that 
these steel crucibles, protected from oxidation in the way I 
have described, may find useful applications for opening 
up other minerals such as rutile, zircons, beryl, monazite, 
and zenotime. 



Royal Institution. — On Tuesday next, January ig, at 
3 o'clock. Prof. Karl Pearson begins a course of two 
lectures at the Royal Institution on " Albinism in Man " ; 
on Thursday, January 21, Prof. J. O. Arnold commences a 
course of two lectures on " Mysteries of Metals " ; and on 
Saturday, January 23, Prof. Sir Hubert Von Herkomer 
delivers the first of two lectures on (i) " The Critical 
Faculty," (2) " Sight and Seeing." The Friday Evening 
Discourse on January 22 will be delivered by Dr. Alfred 
Russel Wallace on '• The World of Life as Visualised and 
Interpreted by Darwinism," and on January 29 by Colonel 
Sir Frederick L. Nathan on " Improvements in Production 
and Application of Gun-cotton and Nitro-glycerin." 



28 



Nature of Chemical Change. 



. Chemical News 
I Jan. 15, 1909 



THE NATURE OF CHEMICAL CHANGE.* 
By HENRY E. ARMSTRONG, 

" That which is far off and exceeding deep, who can find it out ? "— 
EcclesiaiUs, vii., 24. 

" Le plus grand ddreglement de I'esprit ost de croire les choses parce 
qu'on veut qu'elles soient."— La I'le de Pasteur: Vallery-Radot, 
P- 233- 

Nothing is more surprising than the apparent unwilling- 
ness of chemists to formulate a consistent and compre- 
hensive theory of chemical change : the text-books are 
silent on the subject. Whatever service — and it is 
not inconsiderable — the ionic dissociation hypothesis may 
have rendered, it has not given us such a theory : its 
advocates tell us merely that, in the case of electrolytes, 
action takes place between the so-called ions, yet only on 
dry land as it were — on leaving the bath ; what happens in 
the case of non-electrolytes we are not informed. Such a 
conclusion is at best little more than a statement that the 
action is between the acting units — a fairly evident pro- 
position ; of the process we learn nothing. Unfortunately 
phrases and phases have taken the place of clear ideas in 
our text-books and every schoolboy prates of ions nowa- 
days. I am tempted to apply Wordsworth's words to the 
situation : — 

" No single volume permanent, no code, 
No master spirit, no determined road 
But equally a want of books and men." 

In replying to the discussion which followed this com- 
munication, I took occasion to animadvert upon the lack 
of chemical feeling displayed by the adherents to the 
physical school and drew attention to the need of 
once more cultivating the use of fingers in the laboratory, 
remarking that we must have practical and not paper 
chemists if we were to regenerate our industries and to 
play the part the President of the Section had advocated 
in h'S Address. I mentioned that prominent representatives 
of industrial chemistry in Germany, in discussing the 
situation with me recently, had deplored the evil results 
which had followed from the unbalanced development of 
so-called physical chemistry, leading, as this has done, to 
the neglect of the practical side and the substitution of an 
off-hand attitude of superiority for that of careful unbiassed 
inquiry so characteristic in days gone by of the German 
school. The effect on the younger generation is disastrous, 
Paucity of judgment will only be recovered when this is 
admitted. It is essential that we should recognise that 
" physical chemistry " is at best only a very minor branch 
of our subject and that the special prominence which has 
been accorded to it of late years is, after all, largely the 
consequence of bold advertisement. Nowhere, in recent 
years, has the uncompromising worship of the cult of the 
ion — the elevation of the ion into the position of an icon — 
been more fashionable than in the United States of 
America : almost every text-book is devoted to the display 
of ionic rites, so that for years to come it will be useless to 
pray that youth be delivered from temptation. 

Surely it were time that we cleared our minds of cant 
and set to work to introduce an element of philosophy into 
our science — that we swept aside the jargon which now 
disfigures our literature and substituted honest straight- 
forward statements of fact or clear admissions of ignorance 
for the specious illusions which have too long been foisted 
upon the unwary student. 

I venture to think that chemists need to be freed from 
the control of the pseudo-mathematical-physical specula- 
tions to which they have heedlessly subjected themselves 
of late years ; that they need to give clear expression to 
that sense of feeling and knowledge of fact which is theirs 
and theirs alone in virtue of contact with actual materials 
in process of change. The speculations of the mathe- 
matician are very properly often guided by pure fancy — 
but chemists are bound to be realists. Our attitude too is 

* The introduction to a discussion on the subject in Section B 
Chemistry) at the meeting in Dublin of the British Association for 
he Advancement of Science. 



very different from that of the physicist,* who is concerned 
mainly with the mere gambols of molecules whose internal 
structure and interactions it is our province to study. 
Physicists appear to have no conception of the depths to 
which we have penetrated nor of the certainty of not a few 
of our methods, a certainty due to the fact that we are 
often able to pile up odds to such an extent that the formal 
correctness of our explanations becomes almost unquestion- 
able. We need to cast off our subserviency to mathematical- 
physical speculation. The physicist is rightly prepared to 
give rein to his fancy and to propound hypotheses to the 
Hth degree of improbability merely in order that he may be 
able to give mathematical expression to his results. It is 
his way of recording as well as of advancing his position. 
We, however, are in no manner called upon either to be 
misled or to be carried away by the apparent agreement of 
hypothesis with fact when expressed in mathematical form. 
We have only to remember that there is an infinite power 
in mathematical expressions of cloaking ignorance as well 
as of summarising knowledge ; that the same expression 
may be applicable to cases in which the operations are 
quite diverse in character or vice versa. Wendell Holmes 
must have had premonition of the reception that was 
to be accorded to the ionic dissociation hypothesis when 
he wrote the lines : — 

" That boy with the grave mathematical look 
Made believe that he had written a wonderful book 
And the Royal Society thought it was true ! 
So they choose him right in ; a good joke it was too ! " 

— The I'lojessor at the Bieakfast Table, 

However much others may contemn our chemical 
feelings and our pedantic regard for facts in opposition to 
mathematical " let it be granted " fiction, let us not forget 
that it is our business to dissect and display the inner 
meaning of the phenomena of chemical change. We have 
been far too generous in allowing well-meaning speculators, 
who have in no way been conversant with the facts 
generally, to dictate a policy to us : it is to be hoped that 
we shall now once more take the control of our affairs into 
our own hands. 

Since 1885, when I first brought the matter before the 
Chemical Section of the Association in my Address from the 
Chair, I have consistently maintained that the generalisa- 
tion upon which we should base our conceptions of the 
nature of chemical change is that postulated by Faraday — 
namely, that chemical affinity and electricity are one and 
the same force. If this view be adopted, it follows that 
the conditions operative in electrolysis are equally operative 
in all chemical interchanges. The important step taken 
by Arrhenius in 1883 was the discovery of a practical 
method which appeared to correlate chemical with 
electrolytic activity. 

It is noteworthy, however, that as far back as 1878, 
Ayrton and Perry contended that the electrical law of 
Ohm is the chemical law — or as they express it: "the 
quantity of chemical action in unit time equals the sum of 
a great number of terms, each of which is an electro- 
motive force divided by a resistance." All that we know 
is in accordance with this view. 

The dissociationist school, following Clausius, always 
contend that the apparent fact that any electromotive force, 
however small, will produce sensible electrolysis in the 
solution of an electrolyte is complete proof that free ions 

* Chemistry and physics are necessarily interdependent disciplines 
— it is impossible to be a chemist without also being to some extent a 
physicist, although apparently the practice of physics is compatible 
with a complete disregard of chemistry. Chemistry did not become a 
science until it availed itself of the balance. Sooner or later, all pro- 
perties must be quantified if an exact expression is to be given of their 
value ; but the introduction of one or two new methods of measure- 
ment cannot be held to justify the treatment of measurement 
work as a separate discipline. Chemistry is a single science -the 
exclusive cultivation of any of the sections into which it may con- 
veniently be divided must always conduce to narrowness of purview. 
The worker who is generally well informed and who applies his wide 
knowledge to the development of some special subject is the true 
specialist ; such men are urgently required at the present day to restore 
the sense of proportion and to promote once more the development of 
the comparative and critical spirit among us. 



Chemical News, i 
Jan. 15, 1909 ' 



Nature of Chemical Change, 



29 



Grm. -molecular 


Grms. of water 


proportion of 


per grm.-molecular 


solute. 


proportion of solute 


0-05 


20000 


010 


1 0000 


l-oo 


1000 


215 


465-1 


300 


333-3 


5'oc 


2000 


6-00 


1667 



Tablk 


I. 








Solute 


HCl 




Solute 


, HNO3. 


Molecular 


VIolecular hydrolytic 


Molecular 


Molecular hydrolytie 


conductivity. 




activity. 


conductivity. 


activity. 


395-54 




334-0 


391-13 


3160 


391-57 




3400 


3»3-o7 


326-0 


330-07 




499 


329-41 


468-0 


279-14 




7869 


281-25 


675-3 


245 29 




II22'0 


250-29 


864-3 


183-05 




— 


191-26 


— 


158-22 




— 


169-48 


— 



are present in solution and that as these are transported by 
the current others are Hberated spontaneously and take 
their place. I have always maintained that this interpre- 
tation should not be put on the facts. The experiment 
quoted by Helmholfz in his Faraday lecture, on which 
reliance is placed, is not a valid proof, as the means used 
to remove oxygen from the liquid (viz., a third electrode 
of palladium charged with hydrogen) could not effect this 
object completely : and some hydrogen would necessarily 
pass into solution, otherwise there would be no equilibrium ; 
the inevitable consequence would be that the electrodes 
would remain more or less polarised. I even venture to 
think that the Helmholtz atomic charge hypothesis is 
entirely open to question. We have been taught to think 
of hypothetical simple ions — free ions — as carrying the 
charges ; but in point of fact the bodies we charge are 
always highly complex viscous electrolytes of low con- 
ductivity ; it may therefore be questioned whether there be 
any proof that individual ions can be charged, whether it 
be not more probable that the charge is always carried by a 
complex system. 

The conditions in a solution are certainly by no means 
simple ; in fact, it is little short of impossible to avoid the 
conclusion that behind the apparent simplicity of Faraday's 
law there is probably a give-and-take process at work of 
which no account can be rendered, the summation result 
of which alone has been taken into account in framing the 
hypothesis. 

The atoflnic charge hypothesis, moreover, is not in 
accordance with our conceptions of valency. Thus in a 
series of oxides taken in the order of their heats of forma- 
tion, commencing with those in the production of which but 
little heat is evolved, such as silver oxide, heat is developed 
if the metal in any one of the oxides be displaced by that 
of the oxide next below it in the series. If the two charges 
of the oxygen atom be given up in the formation of the 
initial term of the series, whence — it may be asked-^is the 
energy derived which is liberated each time on passing 
to an oxide having a higher heat of formation ? It cannot 
well be supposed that the oxygen remains a non-contributor 
and that the energy is derived from the metal alone; 
whatever the nature of the process, metal and oxygen are 
in some way reciprocal agents. In like manner, the pro- 
perties of water are incompatible with the assumption 
that the two single charges of the two hydrogen atoms 
simply neutralise the two charges of the oxygen atom. 
Physicists have never attempted to deal with facts such 
as these. 

The conception of a definite "valency volume" recently 
introduced by Barlow and Pope may well prove to be 
applicable to the problem : it is conceivable that the 
volume of material displaced in electrolysis is in some way 
proportional to the power of the displacing agent. 

The majority if not all of the results arrived at by the 
application of the ionic dissociation hypothesis are inde- 
pendent ot the fundamental premises which underlie it and 
depend merely on the recognition of the fact that the order 
in which electrolytes exercise their chemical activity is 
practically the order of their activity as electrical con- 
ductors in an electrolytic circuit. Any hypothesis which 
would satisfy this relationship might take its place ; indeed, 
for many purposes of calculation, it is probably unneces- 
sary to go further than to assume that it is established and 



to make no hypothesis in explanation of the fact ; whilst 
in cases in which it is necessary to g» further, it is prob- 
able that the phenomena are by no means so simple as is 
supposed and that conclusions based on the application of 
the hypothesis cannot be accepted even provisionally. 

The fact that discussion has been confined almost 
entirely to weak solutions has been a most fertile source of 
misconception : when all degrees of concentration are con- 
sidered, results are arrived at which are by no means such 
as should follow from the premises adopted. Comparing, 
for example, electrical conductivity with hydrolytic activity 
— although the order of activity of a series of hydrolysts is 
that of their activity as electrolytes, in the one case 
(hydrolysis), there is a decrease, in the other (electrolysis) 
an increase of " molecular " activity as the concentration 
is diminished ; fuithermore, when nitric is compared with 
chlorhydric acid, whereas the hydrolytic activity of the 
nitric is always inferior to that of chlorhydric acid at all 
concentrations and the more so the weaker the solution — 
in the case of conductivity, in moderately and very dilute 
solutions chlorhydric acid is a better conductor than nitric 
acid but in concentrated solutions it is a worse conductor, 
the difference becoming the more pronounced the stronger 
the solution. The values given in Table I. have been 
obtained by Mr. Wheeler and myself in a set of pre- 
liminary experiments. 

There is a well-known adage that you cannot have your 
cake and eat it : if conductivity and hydrolytic activity were 
both properties to be referred to the operations of dis- 
sociated ions, they should run not only on more or less 
parallel lines but also in similar directions : in point of fact, 
they run in opposite directions ; it is rational, therefore, to 
assume that the two processes are essentially different in 
character, not similar as the dissociationist school would 
have us believe. 

The Faraday theory of chemical change, as I propose to 
term it, involves the assumption that the conditions 
operative in a voltaic cell must be realised before any 
change can take place— that is to say, that a conducting 
system must be established consisting of at least three 
components ; no less a number, I imagine, will afford a 
slope of potential. One of the components must be an 
electrolyte : of the two remaining members of the system, 
the one must be a substance— a metal, for example— with 
which the negative radicle of the electrolyte can be 
associated; the other maybe either active or neutral (in 
the chemical sense) towards the positive radicle of the 
electrolyte. The only difference between the case of a 
voltaic battery and that of a chemical change taking place 
in a fluid mixture without electrodes is that in the battery 
conducting electrodes or feelers are introduced which 
enable us to tap the circuit and utilise the energy set free 
in the interactions. In a fluid medium, this energy is 
frittered down into heat : in any case, our chance of being 
able to utilise the energy of chemical change as electricity 
depends on our ability to interrupt the circuit by the inter- 
position of conducting terminals. 

The remarkable results arrived at by Dixon and by 
Brereton Baker with which, it may be supposed, all are 
familiar,* have always appeared to me to afford complete 



+ It is noteworthy that they are enirirely disregarded by the ionic 
dissociationist school. 



30 



Wide Distribution of Scandium. 



J Chemical Nf.ws, 
( Jan. 15, 1909 



justification of the above conclusions. Baker's observa- 
tions show that liquid water alone does not promote the 
interaction of hydrogen and oxygen gases ; change only- 
takes place when impurity is present — that is to say, when 
the water becomes a composite electrolyte. Larmor, in his 
recent Wilde Lecture, has dwelt on the probability of 
encounters taking place bctu'cen pairs of the different 
molecules rather than between any greater number of 
molecules in a mixture of gases. I venture, however, to 
think that the experimental evidence is of so convincing a 
character that it ma}' be affirmed that whatever the 
statistical probability of an effective meeting may be, the 
mating of the hydrogen and oxygen molecules is neces 
sarily dependent on the advent of a suitable composite 
electrolyte : so that the patience of the molecules within 
the mixture must be exercised until proper opportunities 
occur for the interchange of affections — i.e., for affinity to 
operate ; probably no great demand is made, because of 
the almost infinite rapidity with which molecular motion 
is propagated in gases, especially under compression. 

From the point of view here advocated chemical inter- 
changes are essentially all associative processes and their 
occurrence is dependent on the operation of a catalyst. 
But of late the doctrine has been promulgated that a 
catalyst is a substance which merely accelerates change — 
not one which directly conditions change ; that the actions 
which take place more or less rapidly under the influence 
of catalysts also take place without them but so slowly 
that their occurrence cannot be detected in a measurable 
time. I venture to question this. Take the case of cane- 
sugar. Does anyone who has really worked with and 
learnt to appreciate this substance believe that any change 
would take place if the pttre compound were dissolved in 
pure water and the solution were preserved in a clean 
vessel and no acid impurity were allowed to gain access to 
it ? And yet a trace of acid would almost immediately 
condition a perceptible change in such a solution. 

In solution, probably, the sugar is to some extent com- 
bined with water and certainly the water must be in 
intimate contact with its molecules : why then does not 
water act to an appreciable extent — why does acid produce 
such an effect ? The dissociationists will answer : — 
Because there are so few hydrogen ions free in water;* 
and that the acid acts by increasing the proportion of 
hydrogen ions. But to what extent can a trace of acid be 
supposed to have this result ? Its effect is altogether out 
of proportion to the extent to which, e.v bypothesi, it can be 
supposed to furnish hydrogen ions. 

But it may be and I contend has been demonstratea that 
hydrogen ions are not the effective cause of hydrolysis — in 
fact, the selective action of enzymes is incompatible 7cith 
the ionic explanation. The effects produced by enzymes 
are in all respects comparable with those produced by acids, 
so that if the action of acids be exercised not by the acid 
molecules as wholes but by hydrogen ions liberated from 
them in solution, enzymes, in like manner, might be sup- 
posed to contribute hydrogen ions, in which case, since 
acids generally act on cane-sugar, enzymes generally 
should effect its hydrolysis ; in point of fact, however, only 
one enzyme is known which has the power (invertase). 

There is now abundant evidence to show that enzymes 
become associated with the particular substances which 
they hydrolyse and there is good reason to suppose that 
they act by carrying water into the circuit of change, 
delivering it exactly where it is required to effect the break- 
down of the molecular complex. There is also good 
reason to suppose that acids act in a precisely similar 
manner — as true catalysts. 

The effects produced by carriers, the use of which is so 
familiar to workers in organic chemistry, may be explained 
in a similar way. 

(To be continued). 

* The conclusion, based on Kohlrausch's observations, that there 
are free ions in pure water is quite illogical : the experiments do not 
justify it and it is impossible to admit that pure water has ever been 
examined or ever will be. 



THE WIDE DISTRIBUTION OF SCANDIUM 

IN THE EARTH. 

By Prof. G. EBERHARD. 

Up to the present scandium has been numbered amongst 
the rarest of the elements occurring on the earth, so that 
but little is known of it, in spite of its obviously very 
interesting chemical properties. In fact, since the experi- 
ments of Nilson and Cleve, who obtained a few grms. of a 
scandium oxide which was not quite pure but still con- 
tained some ytterbium,* further work upon this element 
has not been published, undoubtedly only because of its 
great scarcity, while, moreover, the working up of the 
expensive minerals which are known to contain scandium, 
and which do not occur in great quantity — gadolinite, 
yttrotitanite, euxenite — by uneconomical and uncertain 
methods (e.g., fusing the nitrates), is a very tedious and 
troublesome process. Thus, according to the statements 
of Cleve (Comptes Rendus, 1879, Ixxxix., 419) and Nilson 
(Ber. , 1S80, x'ui., 1439), the three above-named minerals 
contain only 0001 — 00015, 0-0005, o'oa per cent SC2O3 
respectively. Another difficulty is one which I encountered, 
namely, that euxenites from different sources do not always 
contain scandium, and, moreover, of gadolinites only that 
from Ytterby appears to contain it. 

If it were concluded correctly from these facts that 
scandium is to be regarded as one of the rarest elements 
occurring on the earth, it would be all the more astonishing 
that outside the earth it undoubtedly occurs in other 
heavenly bodies in abundant quantities. Rowland, in the 
identification of the Fraiinhofer lines of the sun's spectrum 
with those of known terrestrial elements, was able to detect 
with certainty some of the strongest scandium lines, and, 
moreover, the scandium lines appeared strongly in the 
spectrum of the sun. At the present time all the lines of 
this element, even the faintest, have been found with 
absolute certainty in the solar spectrum. 

Moreover, not only in the solar absorption spectrum, but 
also in the emission spectrum of the sun's atmosphere 
(flash spectrum), seen for a few seconds during total 
solar eclipses, the strongest scandium lines have been 
recognised amongst those of the few elements occurring 
there. There can thus be no doubt that scandium is 
present in relative abundance in the sun. 

The same is true of the stars. By examining their 
spectra it is found that the scandium lines appear plainly, 
and not only in those stars which resemble the sun. As 
soon as a star has advanced so far in its development that 
the number of lines in its spectrum is large (Vogel's Spectral 
Class I.aj) the lines of scandium appear, generally very 
clearly. As an example, I may mention the star o-Persei, 
which has not yet reached the stage in which our sun now 
is. Also in the red stars, e.g., a-Orionis and a-Herculis 
(Class III. a) which have long passed the state of the sun, 
the scandium lines are still visible and unaltered. 

From the first it seemed clear to me that there cannot 
actually be this difference in the composition of the sun 
and stars on the one hand, and the earth on the other, as 
such a difference would contradict the cosmogonic theory, 
which assumes a common origin of all the heavenly bodies. 
It is rather to be supposed that scandium occurs more 
abundantly on the earth, if perhaps in a state of great 
dilution, and sufficient search has not been made for this 
element, or else it has been overlooked in analyses of 
minerals. It is only necessary to call to mind the 
analogous case of helium, which was long known to occur 
in the sun, but was not discovered on the earth till a much 
later date, owing to more refined methods of analysis. 

When therefore in 1901, in measuring the spectrum of 
the stars, I observed the occurrence of the scandium lines, 
I decided that I would go deeper into the question, and 
search for scandium on the earth by a spectrographic 



* Exner and Haschek in their investigation of arc spectra (p. 145) 
have found ytterbium in Nilson's scandium, and 1 myself have found a 
not inappreciable amount of ytterbium and thorium in Cleve's 
scandium. 



Chemical News, I 
Jan. 15, 1909 I 



Wide Distribution of Scandium. 



31 



method. As it was evident that this element would occur 
in a state of great dilution in the crust of the earth, I first 
tried to obtain information about the sensitiveness of the 
spectral reaction of scandium, so as not to work in vain. 
As I had no scandium at that time, after thorough practical 
study of the chemistry of the rare earths, I chose, to settle 
the question, one of those minerals which are known to 
contain scandium. When o'l grm. of the oxides of two 
different yttrotitanites (Nos. 247 and 248) were vaporised 
in the arc, both showed very plainly the principal 
scandium lines. They were also still plainly visible after I 
had diluted the oxides to one-tenth the strength with 
yttrium earths free from scandium, and again vaporised 
Q-i grm. of this preparation. As according to Cleve the 
oxides of yttrotitanite contain o'oo5 per cent SC2O3, the 
spectral reaction of scandium must be regarded as extra- 
ordinarily sensitive, even if the yttrotitanite oxides contain 
ten times as much scandium as Cleve states, which, 
according to my experience, seems to be the case. In any 
case, on the ground of this experiment, it seemed very 
promising to proceed to the spectrographic examination of 
minerals for scandium. 

I first used minerals in which, according to the experi- 
ments of Nilson and Cleve, scandium might be supposed 
to occur, euxenite (Nos. 2i4and 217) and gadolinite (Nos. 
226 and 227) without, however, detecting this element. 
This was the case when I examined a piece of gadolinite 
from Ytterby, most kindly sent to me by Dr. Benedicks 
(Upsala), but here I observed phenomena which surprised 
me, and which led me to perform further experiments. 
After three extractions of the very finely divided mineral, 
the unextracted part contained considerable amounts of 
alumina and beryllium earth. (All the gadolinites examined 
by me contained beryllium earth, in spite of the statements 
to the contrary in literature). Moreover, the scandium 
lines appeared in the arc not much fainter than in the part 
which had gone into solution, while the lines of the rare 
earths, and especially those of yttrium, had been much 
weakened. This behaviour of the unextracted part led me 
to suppose that the felspar-like matrix adhering to the 
gadolinite, which I had not removed in the working up of the 
mineral, and which cannot be extracted with acids, must 
be a silicate of alumina containing beryllium and scandium, 
for pure gadolinite would be completely extracted by the 
three processes. 

To test this supposition, I asked Dr. Benedicks for 
specimens of the matrix rocks of Ytterby gadolinite, and 
meanwhile investigated another beryllium alumina silicate, 
a smaragd (No. 25) which I happened to have. It 
contained easily detectable quantities of scandium, and, 
moreover, the other rocks found in the Ytterby mine, 
felspar, mica, and mica-schist, contained scandium, the 
last two to a considerable extent. Thus, for the first time 
it was proved that scandium might occur in other minerals 
as well as in those of the rare earths, and simultaneously 
the direction in which further search for scandium should 
be made was indicated. It was found that this element 
was present in a series of beryllium minerals and of micas. 
Among the micas tested, zinnwaldite from Zinnwald in the 
Ore Mountains contained specially large amounts of 
scandium, and when I examined whether other minerals 
from Zinnwald also contained scandium I found a great 
number contained this element, among them tinstone 
(Sn02) and wolframite, which occur in large quantities and 
are rich in scandium. 

But if micas contain scandium, rocks of which mica 
(especially biotite) forms an essential constituent, e.g., 
granite, gneiss, mica-schist, &c., must also contain 
scandium. This conclusion I also confirmed, thanks to 
the extraordinary spectral sensitiveness of scandium in the 
great majority of cases, and I now undertook the examina- 
tion of as many different kinds of minerals and rocks as I 
could obtain from all possible places upon the earth, to see 
if they contained scandium, in order to acquire an adequate 
knowledge of the occurrence of this element, which had 
hitherto been thought to be so rare. 



Before I give the results obtained I will make some 
remarks upon the details of the experiments. The minerals 
of the rare earths, especially the titanates, niobates, &c., 
give a spectrum which is so extraordinarily rich in lines 
that they must be worked up chemically before their 
spectra are photographed ; i.e., must be decomposed into 
their chief constituents. (Prof. R. J. Meyer, Berlin, very 
kindly performed for me in his laboratory part of the very 
tedious and lengthy extraction processes. This renowned 
authority upon the chemistry of the rare earths often gave me 
valuable advice upon the further working up of the raw rare 
earths, and I am glad to take this opportunity of expressing 
my thanks to him). The part which could be extracted 
with acids was first separated from the non-extractive part, 
and the former was then further separated by treatment 
with oxalic acid into a part which was precipitated by this 
acid, and a part which w^s not precipitated by oxalic acid 
but gave a precipitate with ammonia. This precipitation 
of the remaining liquors with ammonia was always neces- 
sary, as scandium oxalate is exceedingly soluble even in 
weak mineral acids, such as the extraction always con- 
tains, and thus a part of the scandium remains in the liquid 
after precipitation with oxalic acid. The rare earths pre- 
cipitated with oxalic acid were subjected to many other 
processes (precipitations, fractional crystallisations) to con- 
centrate the scandium, but I will not now go into the details 
of these operations. 

The preparation of other minerals and rocks was 
essentially simpler. They were first finely powdered and 
then heated to a bright red heat for some time in a 
porcelain crucible to remove the gases and water contained 
in them. If this preliminary treatment is neglected 
unpowdered particles spirt with little explosions, and 
powdered pieces crumble up as soon as the arc is started. 

All preparations were vaporised with the same strength 
of current so as to obtain spectra under the same con- 
ditions, and a comparatively strong current was chosen 
20 A. at 120 volts), because some minerals, e.g., quartz, 
zircon, bauxite, &c., are thoroughly vaporised only at 
high current strengths. The vaporisation is carried out 
in ordinary somewhat hollowed out arc lamp carbons, as 
with currents between 5 and 40 amperes I could not, with 
the rods of far purer Acheson graphite given me by Prof. 
Muthmann (Munich), get anything but a very strongly 
hissing, unsteady, and easily interrupted arc. Two pre- 
cautions are so important for taking the photographs that 
failure usually follows their neglect. F"irst, large quantities 
of material (in my experiments about 0-5 grm.) must be 
vaporised, as scandium mostly occurs only in extremely 
small amounts in the minerals, and only when large 
amounts of material are used are its spectral lines visible 
(in the photographs. But when such large quantities of 
substance are vaporised on the arc carbon, generally a 
fairly bright continuous spectrum appears, which would 
completely mask the faint scandium lines. Therefore a 
spectrograph with very large dispersion must be used to 
efface the continuous spectrum sufficiently. I took the 
spectra with a concave grating apparatus of the observatory 
(Zeitschrift fiir Instrnmentenkunde, 1905, xxv., p. 371) 
and by means of it could practically completely suppress 
the continuous spectrum. 

The second condition necessary for the success of the 
experiment is that the substance put in the arc carbon 
must be completely vaporised until all spectral lines dis- 
appear, which can easily be seen by observing the arc 
with a good pocket spectroscope. The vaporisation of 
rocks in the arc corresponds to a fractional distillation, 
the greater part of the most volatile constituents {e.g., the 
alkalis) vaporises at the beginning of the process, while 
most of the difficultly vaporised constituents, to which 
scandium belongs, vaporise quite at the end. If then a 
large quantity of mineral were put on to the arc carbon, 
and the photographs of the spectrum were taken as soon 
as a small portion or the substance had vaporised, no 
indication of the less volatile elements {e.g., Sc, Zr, Th, 
Ta) would be obtained in the resulting spectrum if they 



32 



Wide Distribution of Scandium. 



IChemtcal News, 
I Jan. 15, igog 



were not present in very large quantities in the mineral, 
and thus an incorrect view of the composition of the 
mineral would be obtained. This mistake has very often 
been made, and to it alone is due our ignorance concerning 
the occurrence of scandium on the earth. 

After these preliminary remarks I give here the minerals 
and rocks investigated by me. (Here the author gives a 
table of 366 minerals and rocks). 

In 131 of them scandium was absent. 

„ 50 ,) „ ). doubtful. 

„ 103 „ „ „ visible. 

„ 62 ,, „ ,) easily visible. 

„ 20 „ „ „ strong. 

366 
In 220 of these minerals the presence of rare earths was 
undetected, in 36 of these minerals the presence of 
rare earths was doubtful, and in no rare earths were 
detected. 
The chief result of the data given in the table is the 
surprising fact of the universal occurrence of scandium on 
the earth. In almost all rocks from which the mountains 
of the earth, or rather the chief parts of the earth's crust 
are formed scandium can be detected, and it is no longer 
a rare element, but, on the contrary, is widely and abun- 
dantly distributed, like only a very small number of other 
known elements. I am of the opinion that it would also 
be found in the rocks in which I did not find it, if larger 
quantities of material than I used were vaporised in the arc. 
From this proof of the universal distribution of scandium 
on the earth it is no longer strange, but natural, that it 
should be found everywhere in the stars and the sun. 

It may be of interest to mention that the meteoric stone 
of Pultusk, which to a certain extent forms a transition 
from the earth to the stars, contains a smaller amount of 
scandium than most of the earth's rocks which I in- 
vestigated. 

Other conclusions may be drawn besides this important 
result. It is evident from the table, as was to be foreseen, 
that among the known minerals a true scandium ore, i.e., 
a mineral which contains scandium as an essential and 
not merely an accessory constituent, has not yet been 
found by me. On the other hand, it appears that scandium 
tnay occur in many different minerals, if it is not a necessary 
constituent. Those in which scandium is to be found 
most frequently are the zircon minerals, beryls, the titanates, 
niobates, and titanoniobates of the rare earths, tin stone, 
tungsten ores, and micas. The quantity of scandium in 
these minerals varies within wide limits, but with a few 
exceptions it is always so very small that chemical analysis 
can hardly detect it. 

The minerals which occur freely and which contain the 
most scandium are some euxenites and yttrotitanites, micas 
from the Ytterby mine, tin stone and wolframite from 
Zinnwald in the Ore Mountains. The last named mineral, 
according to a quantitative analysis by Prof. R. J. Meyer, 
confirmed spectrographically by me, contains about o'2 per 
cent SC2O3 ; thus an amount which is at least ten times 
greater than that of euxenite and yttrotitanite, so that 
there is no longer any obstacle to the preparation of larger 
quantities of the element. There seems to be no rule 
about the occurrence of scandium in the minerals. When 
a large piece of gangue from Hittero, which consisted of 
felspar, quartz, biotite, iron ore, orthite, gadolinite, 
malacon, thorite, was examined, I found scandium in the 
biotite and malacon, but not in the orthite, gadolinite, and 
thorite, which contain the rare earths, where it would be 
expected according to our former knowledge of the pro- 
perties of this element. 

There seems, moreover, to be no rule about the occur- 
rence of scandium in rocks. It is to be found in rocks of 
all possible chemical composition and petrographic con- 
stitution. The amount of scandium is also subject to 
considerable variations, but is always exceedingly small. 
In some cases the amount of scandium seems to be pro- 



portional to the amount of mica which belongs to the 
essential constituents of the rock. This is the case, for 
example, with many granites. On the other hand, how- 
ever, some mica schists have not as much scandium in 
them as would be expected according to this, and if garnets 
have separated the mica schist has become free from 
scandium and all the latter has gone into the garnets. 

The wide geographical distribution of minerals and rocks 
containing scandium indicates that there is no rule for the 
occurrence of scandium from a geological point of view. 
As a matter of fact it is immaterial for the occurrence of 
this element whether the rocks are of sedimentary, plutonic, 
or volcanic origin, and whether they were formed before 
the beginning of historical geology (archaic rocks) or at 
the present time (Vesuvius lava). The table contains 
rocks which were formed in the most different geological 
periods, although there is no apparent difference as regards 
the scandium. Also geological processes, such as endo- 
genous and exogenous, contact metamorphosis, impregna- 
tion metamorphosis, pneumatolysis, are without apparent 
influence upon the occurrence of this interesting element. 
The same holds good of the neighbourhood of radio-active 
minerals, as the investigation of the minerals and rocks of 
Joachimsthal and Johanngeorgenstadt shows. All these 
negative results in the study of the laws regulating the 
occurrence of scandium, both from a mineralogical and 
geological point of view, indicate that scandium must be a 
very widely distributed element on the earth, like iron, 
which is found everywhere. It may be remarked here that 
the distribution of the rare earths seems to be exceedingly 
general. I have made observations on the occurrence of 
these elements in this research, and as lanthanum and 
yttrium have a very great spectral sensitiveness I have 
very often detected the rare earths, mostly with scandium. 
However, this last element may occur without the rare 
earths, and this is perhaps a support of Urbain's view, 
that scandium is not to be reckoned amongst the rare 
earths. For the chief characteristic of these elements is 
that they are always present simultaneously in numbers, 
if in relatively different quantities. No case is known in 
which one of the elements of this group occurs alone 
without being accompanied by at least one of the others, 
which is actually the case with scandium. 

After it has been found possible owing to the foregoing 
work to obtain larger quantities of scandium it is to be 
hoped that this element will be subjected to a thorough 
chemical and especially physicochemical investigation, 
(Note. — This investigation has meanwhile been begun by 
Prof. R. J. Meyer, with great success). I have repeatedly 
convinced myself in the course of the chemical preliminary 
operations for the above investigation that the chemical 
properties of scandium are only very imperfectly known, 
and that scandium must have many reactions which are 
not yet generally known. 

I have further examined the occurrence of large quan- 
tities of scandium in and near Zinnwald in the Ore 
Mountains, a research which has given results of great 
interest geologically and of general importance, but this 
investigation cannot be finished until I have collected a 
large series of rocks and minerals (which up to the present 
I have not been able to obtain). Hence the publication of 
the results so far obtained will be deferred till the research 
is finished. 

I have been enabled to carry through this investigation 
by the kindness of my late chief, Geheimrat Vogel, who 
procured me the means of obtaining research material, of 
Dr. Credner (Leipzig), and Dr. Benedicks (Upsala), who 
sent me some rocks and minerals which were of great 
value for my work. I offer them all my hearty thanks. 
— Sitzungsber. der K. Preuss. Akad. der Wissenschaften, 
xxxviii., 851, July 23, 1908. 

(Note. — While this article was in the press I heard of a 
Note (Proc. Royal Soc, London, Ixxx., p. 516) by Sir 
William Crookes, who has recently prepared scandium 
from the very rare mineral wiikite). 



Chemical News, I 
Jan. 15, 1909 f 



THE CORROSION OF IRON.* 



Corrosion of Iron. 



33 



By ALLERTON S. CUSHMAN, 

Assistant Director, Office of Public Roads, Dept. of Agriculture, U.S.A. 

(Continued from p. 17). 

The Action 0/ Hydrogen Peroxide on Iron. 
Perhaps the most conclusive proof that electrolytic action 
must take place before rusting can occur is given by an 
experiment of Moody's, vi^hich has been repeated and con- 
firmed by the writer. Dunstan and his co-workers claimed 
that when iron is placed in hydrogen peroxide the metal is 
rapidly oxidised, with formation of ferric hydroxide. As 
Moody has pointed out, commercial hydrogen peroxide is 
invariably acid and contains impurities. In perfectly pure 
hydrogen peroxide bright iron will catalytically disengage 
oxygen and retain its polished surface unacted upon. It 
is not an easy matter to prepare a perfectly neutral pure 
solution of hydrogen peroxide, but it can be accomplished 
by two fractional distillations at 85" C. under reduced 
pressure (700 mm.) of commercial dioxygen. Before dis- 
tilling the second time the solution should be made barely 
alkaline with a few drops ofone-hundredth normal potassium 
hydroxide. In a pure neutral i per cent solution of 
hydrogen peroxide thus prepared, Moody's observation was 
confirmed. Iron immersed in the solution remained bright 
for a protracted period. Hydrogen ions do not exist in a 
pure neutral solution of peroxide ; therefore neither solu- 
tion of iron nor electrolysis can take place. If the flask 
containing the specimens covered by pure hydrogen per- 
oxide solution is connected to a vacuum pump, oxygen is 
disengaged freely and boils off the surface of the metal 
without the appearance of the slightest speck of rust. 

Reduced to its simplest terms, the following explanation 
of the rusting and corrosion of iron seems to the writer the 
only one that is tenable. In order that rust should be 
formed iron must go into solution and hydrogen must be 
given off in the presence of oxygen or certain oxidising 
agents. This presumes electrolytic action, as every iron 
ion that appears at a certain spot demands the disappear- 
ance of a hydrogen ion at another, with a consequent 
formation of gaseous hydrogen. The gaseous hydrogen 
is rarely visible in the process of rusting, owing to the 
rather high solubility and great diffusive power of this 
element. Substances which increase the concentration of 
hydrogen ions, such as acids and acid salts, stimulate cor- 
rosion, while substances which increase the concentration 
of hydroxyl ions inhibit it. Chromic acid and its salts 
inhibit corrosion by producing a polarising or dampening 
effect which prevents the solution of iron and the separation 
of hydrogen. 

Demonstration 0/ Electrolytic Action. 
Early in this investigation the writer observed that 
whenever a specimen of iron or steel is immersed in water 
or a dilute neutral solution of an electrolyte to which a 
few drops of phenolphthalein indicator had been added, a 
pink colour is developed. If the solution is allowed to 
stand perfectly quiet it will be noticed that the pink colour 
is confined to certain spots or nodes on the surface. The 
pink colour of the indicator is a proof of the presence of 
hydroxyl ions and thus indicates the negative poles. Many 
persons who are interested in the metallurgical problems 
connected with the iron and steel industry may not be 
familiar with the modern theory of indicators, and therefore 
an explanation of the manner in which phenolphthalein 
shows the presence of hydroxyl ions by the formation of a 
pink colour will not be out of place. Phthalic acid was 
first prepared by Laurent in 1836 by the oxidation of 
naphthalene, and was first called naphthalinic acid. It 
was afterwards shown that the compound was not directly 
related to the naphthalene structure, and Laurent changed 
the name to phthalic acid, the derivatives of which became 

* Bulletin No. 30, U.S. Department of Agriculture, Office of 
Public Roads. 



known later as phthaleins. Phenolphthalein is a product 
which is formed by the condensation of two molecules of 
phenol or carbolic acid with the anhydride of phthalic acid. 
It is in its nature so weak an acid that it is not dissociated 
in solution, and as the molecule is colourless, no colour is 
seen when it is added to a perfectly neutral solution. If, 
however, an alkali is added the corresponding salt of the 
weak acid is formed, which immediately dissociates with 
the formation of a colourless metallic cation and the 
strongly rose-coloured organic anion. Thus all hydroxides 
of basic elements will show the pink colour in solution, 
even when present in only the slightest excess. On this 
account phenolphthalein is an exceedingly delicate indicator 
of the presence of hydroxyl ions. 

Sitice phenolphthalein shows only the nodes where 
solution of iron and subsequent oxidation can not take 
place. Prof, W. H. Walker suggested the addition of a 
trace of potassium ferricyanide to the reacting solution, in 
order to furnish an indicator for the ferrous ions whose 
appearance mark the positive poles (see Note). If iron 
goes into solution, ferrous ions must appear, which, with 
ferricyanide, form the well-known Turnbull's blue com- 
pound. Going a step further. Walker suggested stiffening 
the reagent with gelatin and agar-agar, so as to prevent 
diffusion and preserve the effects produced. For this com- 
bined reagent, which indicates at one and the same time 
the appearance of hydroxyl and ferrous ions at opposite 
poles, the writer has suggested for the sake of brevity the 
name "ferroxyl." The reagent is prepared and used in 
the following manner : — A hot solution of the purest agar- 
agar or gelatin in distilled water is carefully neutralised 
with one-hundredth normal potassium hydroxide, using 
phenolphthalein as the indicator. When exact neutrality 
has been obtained a few drops of a dilute solution of po- 
tassium ferricyanide is added. When a layer of the 
reagent is poured into a dry Petri dish floating in ice water 
it should stiffen into a firm jelly in a few minutes. The 
polished specimens are laid carefully on the jelly and 
flooded with another layer of the reagent. After the pre- 
paration has hardened it should be covered and set away 
in a cool, dark place. In the course of a few hours the 
negative and positive zones will begin to develop in red 
and blue. If the reagent has been properly prepared the 
colour effects are strong and beautiful. In the course of a 
few days the maximum degree of beauty in the colours is 
obtained, after which gradual deterioration sets in. 

(Note. — Phenolphthalein is used to a large extent in 
empirical tests, as in dairying, the cement industry, soil 
examinations, &c. The name is cumbrous if not alarming 
to the layman, while the chemist does not need to be re- 
minded of the origin of the compound each time he has 
occasion to speak of it. A shortening of the name of the 
indicator to " phenolin " would be a decided improvement). 

In the pink zones, as would naturally be expected, the 
iron remains quite bright as long as the pink colour per- 
sists. In the blue zones the iron passes into solution and 
continually oxidises, with a resulting formation of rust. 
Even the purest iron develops the nodes in the ferroxyl 
indicator, but impure and badly segregated metal develops 
the colours with greater rapidity and with bolder outlines. 
This result would of course be expected, as in pure iron 
the formation of poles would be conditioned by a much 
more delicate equilibrium than in impure iron, where 
changes in concentration of the dissolved impurities would 
stimulate the electrolytic effects. Even so-called chemically 
pure iron contains small quantities of dissolved gases, and 
it is not improbable that even slight variations in the 
physical homogeneity of pure iron will occasion the 
electrolytic effects which are made visible by this delicate 
reagent. 

It has been noted by a number of investigators that 
different samples of iron and steel do not rust in the same 
way when subjected to the action of water and air. 
While some samples show localised electrolytic action, 
as indicated by deep pitting, others become covered with 
a more or less homogeneous coating of hydroxide, which 



34 



Practical Sanitation. 



Chemical News 
Jan. 15, 1909 



shows little or no tendency to localise in spots or nodes. 
The question naturally arises : In what respect do these 
two methods of rust formation differ ? In the ferroxyl 
tests, when the colours first developed, two dark blue 
nodes formed at the opposite ends of the test-piece, with a 
large pink area in the centre, where for a time the metal 
remained quite bright. Very shortly, however, the poles 
changed, and the pink central area disappeaitd and gave 
way to a large blue node which enveloped three-quarters 
of the test-piece, with a small opposed pinkish spot. 
Again and again a reversal and change of poles took place. 
There were at least five such changes. As a result of this 
action the metal strip was rapidly covered over its entire 
surface with the same superficial, loosely adherent coating 
of hydroxide, which is obtained in many cases when 
certain samples of iron and steel are allowed to rust under 
a layer of water. It is presumable that as the surface 
of the metal is eaten into by the solution of the iron 
at the positive poles, a new condition of equilibrium 
occurs, resulting in changes and even reversals of 
the positive and negative nodes. This would indicate 
that in the case of metals which suffer from local action or 
pitting the segregation conditions are of a different nature 
from those which exist in the case of metals which rust 
more evenly. A rough analogy may be drawn by imagining 
an imperfect mixture of black and white sand, the re- 
spective grains of which may lie in streaks, spots, and 
layers, or may tend to arrange themselves in some more or 
less uniform relation to each other. The best demonstration 
that the rusting and corrosion of iron and steel in all its 
forms is essentially an electrolytic phenomenon is afforded 
by the fact that it has not as yet been possible to find a 
specimen of such purity that no trace of positive and 
negative nodes will be formed in the ferroxyl indicator. 
(To be continued). 



CORRESPONDENCE. 

POTENTIAL ENERGY OF THE ELEMENTS. 

To the Editor of the Chemical Nezvs. 
Sir, — In the Chemical News of September 4, 1908 (vol. 
xcviii., p. 120) I find a letter by Mr. D. J. Rankin on the 
" Potential Energy of the Elements." The following table 
is given : — 

K. Atomic weight. 

Helium 134,487 4 

Sodium 23,338 22-88 

Calcium 13.415 397i 

Strontium 6,141 8694 

Barium 2,516 i36"4 

A simple relationship exists between the numbers in each 
column. The ratio of the chemical potentials is 6 to i 
approximately for helium-sodium, and taking the column 
downwards 2 to i approximately. In the second column, 
that of the atomic weights, the ratios are approximately 
the same reversed. — I am, &c., 

J. C. Thomlinson. 
6, Villa View, Low Fell, Gateshead, 
December 25th, 1908. 



Method of Preparing Ethylene Hydrocarbons 
from Ether Salts. — Albert Colson. — When ethyl 
benzoate is heated in a sealed tube to 300^^ it remains 
unaltered, but at a temperature of from 305 — 310° 
it decomposes into benzoic acid and ethylene, 
C6H5.CO2.C2H5 = C6H5CO2.H -f C2H4. The vapour tension 
of the ethylene formed appears to remain constant at 310^. 
Stearic ether also undergoes the same decomposition, 
while the ethers of mineral acids similarly give the ethylene 
hydrocarbon. Thus the usual method of preparing 
ethylene is not an isolated example, but is a particular case 
of this general reaction. — Coviptes Rendus, cxlvii.. No. 22. 



NOTICES OF BOOKS. 

Laborafoyy Manual of Qualitafive Analysis. By Wilhelm 
Segerblom, A.B. New York, London, Bombay, and 
Calcutta : Longmans, Green, and Co. 1908. 
This manual on qualitative analysis will be found to 
inculcate useful virtues in the student, and can be recom- 
mended as giving a very suitable scheme of study in 
analytical work. The bases and acids are divided into the 
usual groups, and all the commoner inorganic acid radicles 
are treated, and in addition the three organic acids — 
oxalic, acetic, and tartaric. Both simple salts and mix- 
tures are included, and in the case of practically every 
reaction the equation is given ; it would, however, be 
better if all the equations for each group were not collected 
in separate sections, for the student is thus tempted to 
skip them altogether. The schemes for the separation of 
different members of the same group are particularly clear, 
and notes are given on special difficulties or the reasons 
for possible failures ; the importance of preliminary work 
on each group is emphasised, and every endeavour is made 
to impress upon the student the need for thought and care 
in qualitative analysis. A collection of questions, mostly 
perhaps rather too simple and obvious, is included on the 
reasons for the various steps, and the student is given no 
excuse for mechanical or slovenly work. A course of 
collateral reading from the standard works on analysis is 
suggested in an appendix. 



Practical Sanitation. By George REin, M.D., D.P.H. 

With an Appendix on Sanitary Law by Herbert 

Manley, M.A, (Cantab.), M.B., D.P.H. Fourteenth 

Edition. London : Charles Griffin and Company, Ltd. 

1908. 

Although described as a new edition this is only a 

reprint of the last which was issued, and noticed in these 

columns not much more than eighteen months ago. The 

appendix on sanitary law which was entirely re-written for 

the last edition is reproduced, and gives very clearly the 

chief provisions of the law relating to the duties of sanitary 

inspectors, with explanatory comments. 



A Text-book of Inorganic Chemistry. By Dr. A. F. 

HoLLEMAN. Issued in English in co-operation with 

Hermon Charles Cooper. Third English Edition. 

New York : John Wiley and Son. London : Chapman 

and Hall, Ltd. 1908. 
The third English edition of this text-book has been 
thoroughly revised, many chapters on subjects which have 
recently undergone rapid development being almost en- 
tirely re-written. It has been brought up to the latest 
possible date, as shown by the numerous references to 
work which has been published within the last few months 
— for instance, the solidification of helium is mentioned. 
A section on the metal ammonia compounds, which 
Prof. Werner has revised, gives an excellent summary of 
this complicated subject. The text is always interesting, 
and the author's lucidity and graphic style cannot fail to 
make the impression produced on the mind both deep and 
lasting. Perhaps as a necessary corollary it must be added 
that occasionally the author shows a disposition to 
dogmatise and state as positive facts some observations 
which are still under investigation ; for example, from 
reading the chapter on the radio-active elements the 
opinion would certainly be formed that the degradation of 
copper to lithium is a perfectly well established and uni- 
versally accepted fact. The great extent of the subject 
which is covered suggests that sometimes the treatment is 
sketchy, although perhaps this epithet can hardly be cor- 
rectly applied to the great majority of the short sections in 
which the author's genius for picking out the salient points 
and throwing aside unnecessary details is well exhibited. 
The book is an interesting and essentially modern text- 
book of inorganic chemistry which first year students may 
use with advantage. 



Chemical News, 
Jan. 15, 1909 



Chemical Notices from Foreign Sources. 



35 



CHEMICAL 



NOTICES FROM 
SOURCES. 



FOREIGN 



NoTK. — All degrees of temperature »re Centigrade unless otherwise 
expressed. 

CoDiples Rendns Hebdomadaires des Seances de VAcadimie 
des Sciences. Vol. cxlvii., No. 24, December 14, 1908. 

Direct Dehydration of Tertiary Alcohols. — Louis 



Henry.— Dimethylisopropylcarbinol, CH3 



OH 



XH3' 



when heated with a slight excess of acetic anhydride 
and some drops of sulphuric acid, gives the two 

C H C H 

hydrocarbons tetramethylethylene, cH^"^^ " ^*^CH^' 

»-'ti3^p Q _ pfT 

and isopropylmethylethylene, CH3 1 . The 

CH3 
real dehydrating agent is not the acetic anhydride but the 
sulphuric acid, and the reaction appears to be a curious 
instance of catalysis. The acetic anhydride is not useless 
in the reaction, for the decomposition of the acetate formed 
takes place more readily than that of the alcohol as such. 
Trimethylenedimethylcarbinol, — 

^^2^ ,CH3 



CH, 



>CH— C< 



CH: 



OH 



does not give the same reaction, and thus the presence of 
a closed chain seems to make the alcohol molecule more 
stable. 

Magnetism of the Rare ICarths.— B. Urbain and G. 
Jantsch. — If the rare earths are arranged in order of their 
atomic weights their magnetism is found to exhibit two 
maxima, one in the cerium and the other in the yttrium 
group. Lanthanum is diamagnetic, praseodymium is 
paramagnetic, but less so than neodymium, which is five 
times as magnetic as samarium. Europium is much 
less magnetic than gadolinium, and the magnetism in- 
creases from gadolinium to terbium and from terbium to 
dysprosium. It is interesting to notice that, by the 
isomorphism of its salts of the same type, bismuth, which 
is diamagnetic, comes between the last term of the cerium 
series (samarium) and the fiist term of the yttrium series 
(europium). 

Preparation of Thorium Chloride. — Camille 
Matii^non.— The author does not recommend the method 
of preparing thorium chloride by COCI2, recently described 
by Chauvenet. He finds that the action of chlorine and 
sulphur chloride provides a general method of chlorinating 
metallic oxygen compounds, and by means of it thorium 
oxide can rapidly be converted into the chloride in glass 
tubes at a temperature below the melling-point of glass. 
The hygroscopicity of the chloride is apparently due to the 
presence of impurities, and the pure chloride absorbs 
moisture only very slowly. The author obtained a value 
for the heat of solution of the chloride in water, which 
is considerably lower than that found by Chauvenet. 

Analysis of Aluminium Powder.— E. Kohn-Abrest. 
—Aluminium powder can readily be analysed by heating 
with an excess of ferric sulphate in an atmosphere of 
carbon dioxide, and determining the amount of ferrous 
salt formed by means of permanganate. ' The equation is 
3Fe2(SO,)3 + 2Al=Al2(S04)3-l-6FeS04. In two analyses 
the author has found that nearly 6 per cent of oxide is 
present, but he cannot positively affirm that this oxide is 
aluminium oxide. 

Dissociation of Sodium Bicarbonate.— M. Soury.— 
The dissociation of sodium bicarbonate is not analogous to 
that of chalk, since two gases are formed, carbon dioxide 
and water, and thus there are three constituents and foiir 
phases. When the bicarbonate moistened with water is 



decomposed at 100° and the vapour tension is determined, 
it is foupd that if increasing quantities of carbon dioxide are 
removed the tension decreases in proportion to the amount 
of carbon dioxide removed. There are two periods of fixed 
tensions. At first the lower carbonate dissolves in the 
water, and when the solution is saturated the new carbonate 
crystallises in contact with the liquid, giving the fourth 
phase indispensable for the existence of the fixed tensions. 
The second series of fixed tensions occurs when the 
carbonate first formed 3Na2O.4CO2.5H2O, dissociates in 
presence of the neutral monohydrated carbonate, 
Na2O.CO2.H2O. 

Action of Sulphur Monochloride on Metalloids and 
Metals. — Paul Nicolardot. — Sulphur, selenium, and yellow 
phosphorus readily dissolve in sulphur monochloride in the 
cold. Arsenic is not attacked, but antimony reacts in the 
cold, while there is no action with carbon, silicon, and 
boron. Among all the metals only tin, aluminium, 
mercury, and iron are affected by treating either with hot 
or cold sulphur monochloride. With iron it is found that 
the monochloride acts like hydrochloric acid and not like 
chlorine. Possibly it has no action on the metals of the 
alkalis and alkaline earths because a very thin layer of 
chloride is formed and stops the reaction. 

Action of Heat on Iodic Anhydride. — Marcel 
Guichard. — When iodic anhydride is heated it undergoes 
no change till a temperature of 300- is reached. It then 
begins to evolve oxygen and iodine, the undecomposed 
part changing colour to brown, and apparently increasing 
in volume. When partially decomposed the anhydride 
retains some oxygen and free iodine very persistently, the 
only substances which can remove the brown coloration, 
which is due to small quantities of iodine, being those 
which dissolve the anhydride and combine with the iodine ; 
for instance, potassium iodide. 

Researches on the Occluded Gases contained in a 
Complex Manganese Brass. — G. Guillemin and B. 
Delachanal — The authors found that the rough castings of 
a manganese brass were covered with little bubbles which 
seemed to be produced at the moment when a particle of 
metal solidified and prevented the escape of the gases 
which were being evolved. These gases escape because 
their solubility in the fused metal is greater than in the 
solidified metal. The gases on analysis were found to 
consist chiefly (79 per cent) of hydrogen, the residue being 
methane, carbon monoxide, and dioxide. The metal 
examined contained three and a-half times its volume of 
occluded gas. 

Waxes of Conifers. New Group of Natural 
Principles. — J. Bougault and L. Bourdier. — From the 
leaves and berries of various conifers {Piuus s) Ivestris, 
yur.ipenis Sabina, &c.), a white crystalline powder, re- 
sembling certain common vegetable waxes, has been 
isolated. This white powder has been found to be a mix- 
ture of various principles which all possess a free acid 
function, a free alcohol function, and also ether functions 
which are one fewer in number than the associated 
alcohol-acid molecules. The authors have isolated two 
acids by saponification : — The one corresponds to the 
formula C16H32O3 (oxypalraitic), and has beeri given the 
name juniperic acid. A large proportion of it is furnished 
by Jiinipems Sabina. The other has the formula 
C12H24O3 (oxylauric), and may be called sabinic acid. It 
has so far been detected only in the part of the wax of 
jfuniperus Sabina which fuses at 82°. 

Synthesis of Derivatives of Camphenylone.— J. 
Bouveault and G. Blanc. — Some time ago the authors 
suggested that the amide which is formed when sodamide 
acts on camphenylone has the formula — 

CH— CH<^S^ 
CH2 CH2 
CHi-CH— CO— NH2 



36 



Meetings for the Week. 



Chemical News, 
Jan. 15, 1909 



This view they have now proved to be correct by synthetical 
methods. ■'-Isopropylcyclopentanone, which is the ultimate 
product of the degradation of the amide molecule, when 
hydrogenated gives a secondary alcohol which is identical 
with that obtained by treating the amide derivative of 
camphenylone with nitrous acid. When heated to 100'^ 
with hydrobromic acid saturated at o', the alcohol yields 
^-isopropylbromocyclopentane, — 

XH2 



CH— CH< 






CHi 



CH, 



CHa-CHBr 
and this when subjected to Grignard's reaction gives 
j8-isopropylcyclopentane carboxyllic acid, from which by 
the action of phosphorus pentachloride and ammonia an 
amide identical with that derived from camphenylone can 
be prepared. The authors have not yet succeeded in 
passing from this compound to camphenylone itself. 

Action of Sulphuric Acid on Aldehyde and Par- 
aldehyde. Preparation of Crotonic Aldehyde. — 
Marcel Delepine. — When aldehyde vapour is led by a 
current of gas into an excess of concentrated sulphuric acid 
at 10 — 15" it is absorbed without any signs of charring, and 
on diluting the liquid with ten parts of water and distilling, 
large quantities of crotonic aldehyde are formed. Also 
when paraldehyde is dissolved in concentrated sulphuric 
acid, the liquid is diluted and distilled, crotonic aldehyde 
P'^'.sses over in the first portions, and at the same time the 
polymer CSH12O2 is obtained. 

Action of Acids on Diiodo-a-methylsparteVn. — 

Amand Valeur. — Diiodo-o-methylspartei'n, which is really 

CH 
the iodomethylatc of an iodoisopartein, NCi5H25lN<j 3, 

when dissolved in dilute sulphuric, hydrochloric, or acetic 
acid, does not give the corresponding sulphate, &c., but a 
compound containing three atoms of iodine of formula 

j">NC,5H25lN <^^^. Probably hydriodic acid is first 

set free, and it then reacts with the unaltered iodomethylate 
to give this compound. \\l can also be removed by boiling 
caustic soda, i-methylspartein being set free: — 
NCi5H25lN(CH3l) +-2NaOH = 

= NCi5H25N(CH3) + 2NaI + O + H2O. 



MISCELLANEOUS. 

Iron and Steel Institute. — The Andrew Carnegie 
Research Scholarship. — A Research Scholarship or 
Scholarships, of such value as may appear expedient to the 
Council of the Iron and Steel Institute from time to time 
founded by Mr. Andrew Carnegie (Past- President), who 
has presented to the Iron and Steel Institute eighty-nine 
one-thousand dollar (5 per cent) Debenture Bonds for the 
purpose, will be awarded annually, irrespective of sex or 
nationality, on the recommendation of the Council of the 
Institute. Candidates, who must be under thirty-five 
years of age, must apply on a special form before the end 
of February to the Secretary of the Institute. The object 
of this scheme of Scholarships is not to facilitate ordinary 
collegiate studies, but to enable students, who have passed 
through a colh ge curriculum or have been trained in 
industrial establishments, to conduct researches in the 
metallurgy of iron and steel and allied subjects, with the 
view of aiding its advance or its application to industry. 
There is no restriction as to the place of research which 
may be selected, whether university, technical school, or 
works, provided it be properly equipped for the prosecution 
of metallurgical investigations. The appointment to a 
Scholarship shall be for one year, but the Council may at 
their discretion renew the Scholarship for a further period 
instead of proceeding to a new election. The results of 
the research shall be communicated to the Iron and Steel 



Institute in the form of a Paper to be submitted to the 
Annual General Meeting of members, and if the Council 
consider the Paper to be of sufficient merit, the Andrevv 
Carnegie Gold Medal shall be awarded to its author. 
Should the Paper in any year not be of sufficient merit, 
the Medal will not be awarded in that year. 

Memorial to Sir George Livesey.— With reference to 
the steps it has been decided to take to perpetuate the 
memory of the late Sit George Livesey, the Committee 
having the matter in hand desire to announce that contri- 
butions to the Fund should be sent to the Secretary of the 
Institution of Gas Engineers, 39, Victoria Street, West- 
minster. A sum of at least ;£'io,ooo is required for the object 
in view — the endowment of a Livesey Professorship in Gas 
Engineering and Fuel at the Leeds University — and con- 
tributions both small and large will be welcomed. Having 
regard to the great services which Sir George Livesey 
rendered the industrial world, and indeed to all classes of 
the community, it is felt that there will be a general desire 
throughout the country to do honour to his memory. 



NOTES AND QUERIES. 

Lantern Slides.— Can any reader inform me whether there is a 
firm having for hire lantern slides illustrating any chemical industries, 
as, for example, the manufacture of sulphuric acid. --T.O.B.B. 



-MEETINGS FOR THE WEEK. 

Monday, i8th.— Royal Society of Arts, 8. (Cantor Lecture), " Public 
Supply of Electric Power in the United Kingdom," 
by G. L. .\ddenbrooke. 
Tuesday, 19th.— Royal Institution, 3. "Albinism in Man," by Prof. 

Karl Pearson, F.R.S. 
Wednesday 20th.— Royal Society of Arts, 8. " Gothic Art in Spain," 
by H. C. Brewer. 

Microscopical, 8. Presidential Address, "On 

Seeds, with Special Reference to British 
Plants," by the Rt. Hon. Lord Avebur\'. K.\- 
hibition of Foraminifera dredged from off the 
coast of Somaliland. 
Thlksday, 2ist.- Royal Institution, 3. "Mysteries of Metals," by 
Prof. J. O. Arnold. 
Chemical, 8.30. " Organic Derivatives of Silicon- 
Part IX., Experiments on the Resolution of 1'/- 
Benzylethjlpropylisobutylsilicane Sulphonic 
Acid," by F. S. Kipping and H. Davies. " Syn- 
thesis of Diurea from Urea," by F. D. Chattaway. 
"Chlorine f^erivatives of Substituted Ureas," by 
F. D. Chattaway and D. F. S. VViinsch. "Che- 
mical Examination of Eriodictyon," by F. Tutni 
and H. W. B. Clewer. " Hydration of Precipi- 
tates," by S. U. Pickering. "Relationship be- 
tween the Constitution and the Absorption 
Spectra of Pyridine and various Derivatives," by 
J. E. Purvis. " Formation of Cyclohexanone 
Derivatives " and " Action of Mustard Oils on the 
Ethyl Esters of Malonic and Cyanoacetic .Acids," 
by S. Ruhemann. "Studies of Dynamic Iso- 
merism Part VIII., The Relationship between 
Absorption Spectra and Isomeric Change, Absorp- 
tion Spectra of Halogen, Nitra-, and Methyl- 
Derivatives of Camphor," by T M. Lowry and 
C. H. Desch. "Interaction of Hydrogen and 
Chlorine," by D. I.. Chapman and P. S. 
MacMahon. "Chloride of Nitrogen," by D. L. 
Chapman and L. Vodden. " .'Atmospheric 0.\ida- 
tion of /8-Methylhydrindone," by A. H. Salway 
and F. S. Kipping. "Mechanism of the Reduc- 
tion of Nitro-anilines and Nitrophenols" and 
" Relation between the Strength of .Acids and 
Bases and the Quantitative Distribution of 
Affinity in the Molecule, ' by B. Fliirscheim. 
"A Glucoside from 'J'fplir sni piirpmea," by G. 
Clarke, jun., and S. C. Bancrjee. "Constitution 
of the Carboxylic Group" and " Relation between 
the Chemical Constitution and Optical Properties 
of the Aromatic a- and 7-Diketoneb," by Miss L 
Smsdley. 
Friday, 22nd.— Royal Institution, 9. " The World of Life, as Visual- 
ised and Interpreted by Darwinism," by Alfred R. 
Wallace, F.R.S., &c. 

Physical, 5. "Effective Resistance and Inductance of 

a Concentric Main, and Methods of Computing the 
Ber and Uei and .Allied Functions," by .A. Russell. 
" Luminous Efficiency of a Black Body" and " Use 
of the Potentiometer on Alternate Current Circuits," 
by C. V. Drysdale. 
Saturday, 23rd.— Royal Institution, 3. " The Critical Faculty," by 
Prof. Sir Hubert von Herkomer, C.V.O., &a. 



Chemical News, 
Jan. 22, 1909 



Mature of Chemical Change. 



57 



THE CHE MICAL NEWS 



Vol XCIX,, No. 2565. 



THE NATURE OF CHEMICAL CHANGE.* 

By HENRY E. ARMSTRONG. 

(Concluded from p. 30). 

It has been the great merit of the ionic dissociation 
hypothesis that it appeared to furnish an explanation of the 
fact that the active mass of a substance is always some 
fraction of the total mass. The fact that different acids 
have different degrees of hydrolytic activity, for example, 
is supposed to be due to the circumstance that at any given 
moment only that part of the acid is active which exists in 
solution in the form of dissociated ions — hence the sup- 
posed degree of dissociation has been regarded as the 
measure of activity. Until an alternative is offered such 
an explanation must prove attractive to those who cannot 
live without an imposed faith. The work which has been 
carried out under my supervision during several years past 
has, I think, made it possible to propound an explanation 
which is both rational and reasonable and generally 
applicable to the phenomena afforded by solutions. The 
subject is dealt with in a recent communication to the 
Royal Society (Proc. Roy. Soc, 1908, Series A, vol. Ixxxi., 
pp. 80—95). 

I assume that wattr is a complex material and propose 
to confine the name to the liquid mixture. The simple 
molecule which we represent by the formula OH2 I would 
term hydrone. Together with such monads there are 
present in water more complex molecules such as — 



HaO^OHa 


H2O— OH2 
OH2 


H2O— OH2 

1 1 
H2O— OH2 


Dihydronc. 


Trihydrone. 


Tetrhydrone. 



And most important of all perhaps are molecules of 

another type, represented by the formula H20<qj^ — 

which I term hydronol. I will not stay to discuss the 
manner in which such molecules are formed — whether 
they could arise in pure water, such a substance being 
only conceivable, not obtainable.! 

When a substance, hydrogen chloride, for example, is 
dissolved in water, it in part becomes hydronated and in 
part hydrolated, compounds such as HC1 = 0H2 and 

HCKqtt and polymerides of like type being formed ; but 
another part is hvdrolysed and converted into the com- 
pound represented by the formula H20<qj, which is the 

correlative of hydronol. Compounds such as alcohol, 
which escape hydrolysis and only become hydronated and 
hydrolated, do not yield conducting solutions: it is only 
in cases in which both solvent and solute become re-distri- 
buted that conducting solutions are obtained — conduction 
being in some way dependent on the interaction of the two 

H HO 

types of molecules H20<^, and ^ >C1H under the in- 
fluence of the current. 

This, I believe, is the first rational explanation that has 
been given of the nature of a composite electrolyte and is 
in agreement with the view expressed by Faraday that the 
determining force is not at the poles but within the body 
under decomposition. 

Subject to certain reservations the polyhydrones and all 
such compounds are to be regarded as inactive, being com- 



* The introduction to a discussion on the subject in Section B 
Chemistry) at the meeting in DubUn of the British .■Vssociation for 
he Advancement of Science. ^ „ . .• , • .u 

+ I have discussed this subject somewhat fully in an article in the 
current number (January, 1909) <3i§e%ence Progress. 



pounds of tetrad oxygen ; the activity of the solution is 
practically dependent on the proportion of molecules 
present either in the monadic or in the hydrolated or the 
hydrolysed state. 

To give two illustrations of the application of the 
hypothesis. According to the dissociationists, when an 
acid is neutralised by an alkali, the only change within the 
liquid consists in the formation of water from the hydrogen 
and hydroxyl ions, e.g., — 

H + Cl-f Na-»-0H = CH-Na + H20. 

Unfortunately for this explanation, after full allowance 
is made for the water produced in the manner shown, it is 
still necessary to account for an expansion in volume 
corresponding to the formation of more than another 
molecular proportion of water. This difficulty disappears 
if the interaction be represented in the following manner : — 



I.HCI<»„ + OH>0<!,?^ 

= HCl- 



•OH H- 



-0<!J^ + OH, 



II. HCl- 



.H 



— 0<" +OH2 = HCI:OHNa-f20H2. 
■^OH H'' ^^ 

III. HCl:OHNa-h20H2 = NaCl + sOH^. 

The proportion of hydrol actually set free and the 
amount of water formed (I. and II.) will depend on the 
amount of associated hydrol in the effective composite 
molecules of acid and alkali together with the molecular 
proportion liberated in the final change (III.), less the 
amount effectively associated with the dissolved salt — at 
most, two molecular proportions, therefore. 

The volume changes are interesting from this point of 
view when determined in a series of solutions containing 
the same molecular proportions of solute and water — not in 
kilogram-normal solutions, the plan adopted by Ostwald. 

Table \l.— Volume oj Weight-normal Molecular 
Solutions at 25^. 

Cc. Ostwald. 

KOH =1014-68 

NaOH =1001-28 

HCl =1021-98 

HNO3 =1033-25 

Water (1000 grms.) =1002-97 

(KOH) + (HCl) = 2036-66 -2005-94 .. = 3072 
KCl=io3i-92 + H20 = i049-97-ioo2-97 = 47-00 

(1805 cc.) 

Expansion = 16-28 19-52 

NaOH -1- HCl = 2023-26- 2005-94 .. .. = i7"32 
NaCI = 1021 -61 + H2O = 1039-66 - 1002-97 = 36-69 

Expansion = i9'37 20-05 

KOH -t-HN03 = 2047-93 -2005-94 . .. = 4i'99 
KNO3 = 1043-48 + H2O = 1061-53 - 1002-97 = 58-56 



Expansion = 16-57 

NaOH -I- HN03 = 2034-53-2005-94 .. = 28-59 
NaNOj = 1033-22 + H2O = 1051-27- 1002-97 = 48-30 



19-24 



Expansion 



= 1971 1977 



The contraction observed when acids are neutralised 
by ammonia, which is especially large in the case of weak 
acids, is accounted for on the assumption that the amount 
of water fixed by the salt is large in proportion to that 
liberated from acid and alkali. 

It is important, as far as possible, to avoid the use of 
"terminological inexactitudes" in describing the pheno- 
mena of chemical change. The word " ions " was mtro- 
duced by Faraday simply " to express those bodies which 
can pass to the electrodes " ; no thought of their freedom 
appears to have been in his mind : indeed it may be 



sS 



Nature of Chemical Change, 



I CHfeMICAL NeWSj 

I Jan. 22, 1909 



claimed that he favoured the idea of association rather 
than that of dissociation (compare his fifth series of 
" Researches," §523). It is desirable to retain Faraday's 
definition of an ion unimpaired and to use the derivative 
terms ionised and ionisation only in a restricted sense : if 
we wish to imply that there is actual separation of the two 
constituent radicles, let us not be afraid to speak honestly 
of dissociated ions. 

From the point of view here advocated, moreover, a 
particular substance should not be spoken of as ionised in 
solution but the solution should be said to be ionised — both 
constituents being reciprocally affected. 

The assumption that both constituents of a solution — 
solvent and solute — take part in electrolysis is in accordance 
with the facts : for example, chlorine and hydrogen are 
practically the sole products only in the case of con- 
centrated solutions of hydrogen chloride ; as the solution 
is diluted, oxygen is obtained in increasing amount 
together with chlorine. 

No proof has ever been given that conductivity is con- 
ditioned by the dissolved substance alone — the so-called 
molecular conductivities are merely a series of numbers 
expressing the conductivities of solutions of equivalent 
strength. 

Weak and concentrated solutions must be regarded as 
containing very different proportions of the two kinds of 
active molecules : in the former, probably hydrolated 

molecules of the solute of the form HX<qtt are present 

in major proportion and, in some way, condition their 
superior activity as electrical conductors ; in the case of 
concentrated solutions, hydrolysed molecules of the solute 

of the form H20<y are the major components and (in 

the case of acids and alkalis) the superior hydrolytic 
activity of such solutions is conditioned by these complexes. 

The so-called osmotic properties and other physical 
attributes of solutions generally may all be regarded from 
the point of view now advocated but I may be allowed to 
refer to my recent communications to the Royal Society 
for an explanation of my views on this question. 

The foregoing explanation of the condition of substances 
in solution should be considered apart from the question of 
the extent to which compounds are hydrated in solution. 
That hydrates are present is now generally admitted, even 
by those who advocate the ionic dissociation hypothesis in 
its extreme form ; but apparently there is an unwillingness 
to allow that the hydrates which separate from a solution 
are to be regarded as having been present in it. Arrhenius, 
for example, in his Californian lectures, concludes an 
account of Meyerhoffer's observations on the freezing- 
points of solutions of sulphuric acid with the statement : — 

" All these maxima and minima tell us nothing of the 
composition of the molecules in the liquid ; they only 
indicate the composition of the substance which freezes out." 

But it is in the highest degree probable that a substance 
which crystallises out from a solution is actually present 
in the solution prior to its separating : in other words, that 
the solid without is in equilibrium with the dissolved sub- 
stance within the liquid in the case of a solution saturated 
in presence of the appropriate solid equilibrator. It is 
clear that the equilibrator has a determining influence in 
causing the separation of solid from the solution before 
this latter is actually saturated : the work of H. A. Miers 
and his coadjutors has shown, in fact, that if a solution be 
cooled in the absence of the appropiiate equilibrator a 
point is reached at which the solution is actually saturated 
and solid then separates spontaneousiy, the temperature 
at which this separation takes place being often considerably 
1 )wer than that at which crystallisation is effected in presence 
of an equilibrator. The mistake that has been made is that 
of assuming that a solution ever consists entirely of any one 
hydrate : probably, however, few have held this view in 
any strict sense. The existence of liquid crystals in solu- 
tion may also be regarded as an argument in favour of the 
existence in solution as definite hydrates of substances such 



as are known to separate in the solid state. But it is also 
conceivable that hydrates exist in solution of an indefinite 
character and that, in any case, the degree of hydration 
must vary with the conditions, not merely because the 
amount of water present varies but also because the con- 
dition of the water, the extent to which it is dissociated into 
hydrone, &c., varies with the concentration. It is to be 
supposed that in concentrated solutions, a major proportion 
is present in the form of hydrone and hydronol and that 
these will exercise a dehydronating and dehydrolating effect 
(in other words, a dehydrating effect), owing to their 
tendency to become water ; this tendency will be less mani- 
fest the weaker the solution ; on the other hand, the inter- 
position of a neutral substance, even though it be incapable 
of exercising directly any considerable dehydrating effect, 
may indirectly bring about a considerable amount of 
dehydration as a consequence of the dissociating influence 
which it exerts on the water with which it is mixed by 
promoting the occurrence of change in the direction 
(0H2).r -> A-OH^. 

It may be doubted whether it will be possible to deter- 
mine the exact degree of hydration of a substance in solu- 
tion by any direct process : probably in every case only the 
average effect can be ascertained ; the conditions in each 
particular system must be special, moreover. 

The activity of acids as hydrolytic agents is increased, 
as a rule, if one of its salts be added to the solution of the 
acid : the concentrating effect thus exercised by the salt 
may be evaluated by determining the degree of dilution 
required to reduce the activity to that exercised by the acid 
alone. The hydration values thus arrived at, however, 
vary according to the nature of the hydrolyte. Thus, 
using gram-normal molecular solutions of hydrolyte and 
hydrolyst, the value arrived at for sodium nitrate by using 
nitric acid and cane-sugar is 11H2O, whereas if raffinose 
be substituted for cane-sugar the value falls to 8H2O, that 
arrived at by means of methylic acetate being still lower, 
viz., 3H2O. There can be no doubt that hydrolysis is a 
reciprocal process and that not only must the strength of the 
acid hydrolyst be taken into account but also that of the 
hydrolyte. Hydration values arrived at in the manner 
referred to cannot be regarded as true hydration values 
but merely as relative expressions of the degree of dis- 
turbance effected by the salt in the solution. Other 
methods of effecting such determinations are doubtless 
subject to similar limitations. It may well be that salts 
are actually m.re fully hydrated in solutions in which they 
apparently exert a minimum effect rather than in those in 
which they seem to act more powerfully. 

Our mistake has been of late years that we have regarded 
the phenomena of solutions from too simple a point of 
view, especially that wc have left the solvent out of 
account : in the long run, we shall be gainers if, as chemists, 
we allow the logic of facts to prevail. 

Erratum. — P. 28, col. i, line 31 from bottom, fur 
" Paucity read " Sanity." 
Chemical Department, 

City and Guilds of London Institute, 
South Kensington. 



Products of Arc and Spark Discharge in Liquid 
Argon. — Franz Fischer and George Iliovici. — The authors 
have investigated the products obtained when liquid argon 
is subjected to arc and spark discharges between metallic 
electrodes in absence of air. Using cadmium electrodes 
they find that cadmium nitride is formed. The nitrogen 
of the nitride gives ammonium salts with acids, and escapes 
as N2 when the nitride is ignited in vacuo. The gases 
which are obtained by heating in vacuo give in aluminium 
electrode tubes first the nitrogen spectrum and then the 
argon spectrum. Argon lines were at once obtained if the 
substance was opened up by the chemical union of the 
nitrogen with phosphoric acid. It appears that the argon 
is only absorbed, but the authors propose to perform 
further experiments with improved apparatus to decide 
this point. — Berichte, xli., No. 15. 



Chemical News, 
Jan 22, 1909 



Corrosion 0/ Iron. 



THE CORROSION OF IRON.* 

By ALLERTON S. CUSHMAN, 

Assistant Oirector, Office of Public Roads*Dept. of Agriculture, I'. S. A. 

(Concluded from p. 34). 

Application 0/ Electrolytic Theory. 
We may now apply the electrolytic theory to the actual 
results obtained in the ordinary rusting of iron. If a 
section of rolled metal, such as sheet or plate, is immersed 
in water, if the electrolytic theory is correct, rusting must 
take place with the establishment of positive and negative 
spots or areas. At the positive points iron will pass into 
solution and be rapidly oxidised to the loose colloidal form 
of ferric hydroxide which is characteristic of rust formed 
under these conditions. It is a well known fact that col- 
loidal ferric hydroxide will move or migrate to the negative 
pole if subjected to electrolysis. We may therefore" con- 
sider the possibility of two separate efifects that may be 
produced, viz., when a positive centre is surrounded by a 
negative area, and vice versa. These two conditions may 
be graphically represented by the two circles a and n 
shown in Fig. 3. 

Now, as rusting proceeds we should expect in the case 
of A that the fertic hydroxide would be piled up in a crater 
formation, while the metal is eaten out at the centre. In 
the case of b the effect would be reversed, and while the 



39 





Fig. 3. — Diagram illustrati.ng Electrolytic Action 
ON THE Surfaces of Iron and Steel. 

metal would be attacked in the surrounding area the 
hydroxide would be piled up in a cone at the centre. That 
this is precisely what is taking place whenever a sheet of 
metal rusts under water a low-power microscope very 
clearly shows. 

The evidence advanced in the preceding pages appears 
to the writer to confirm the conclusion that the whole 
subject of the corrosion of iron is an electro-chemical one, 
which can be readily explained under the modern theory 
of solutions. It is an undeniable fact that some irons and 
steels suffer corrosion very much more rapidly than others, 
and the underlying causes for these differences constitute 
one of the most important problems of modern metallurgy. 

Although the discussions brought forward in this bulletin 
are mainly theoretical in their nature, it is quite apparent 
that they also have an indirect practical bearing. Before 
advance can be made in overcoming the difficulties in ihe 
way of manufacturing iron which shall have the maximum 
resistance to corrosion, as well as the preservation of the 
metal under the conditions of service, the underlying 
causes must be thoroughly understood. If we accept the 
electro-chemical explanation of the corrosion of iron, there 
can be no doubt that conditions which inhibit electrolytic 
effects also inhibit corrosion, and vice versa. The purer 
the iron in respect to certain other metals which differ 
electro-chemically from iron and the more carefully lack 
of homogeneity and bad segregation are guarded against 
the less likely are the electrolytic effects to become serious. 
These points constitute the essential problems which con- 
front the manufacturer who desires to make a product 



* BuUetin No. 
Public Roads. 



30, U.S. Department of Agriculture, Office ot 



which shall have a high resistance to corrosion. The 
user and consumer, however, are interested in the pro- 
tection of the various types of merchantable iron and steel 
which are available under market conditions at the present 
time. In short, protective coatings and palliative methods 
of treatment are in greater demand today than ever before. 
From the standpoint of the electrolytic theory many sug- 
gestions for experiment under the conditions of service 
present themselves. The fact that hydroxyl ions inhibit 
the rusting of iron has been made practical use of for a 
long time past, and it is not unusual to add caustic alkalis 
to boiler waters for this reason. This, however, frequently 
causes trouble from foaming, and, as Cribbhas shown {loc. 
cit., p. 15), if an insufficient amount of alkali is present 
the pitting effect is accentuated rather than inhibited. 
This observation is in accord with the theory that the 
hydroxyl ions must reach a certain concentration, which 
varies with different conditions, before entire prohibition of 
the electrolytic effects is obtained. 

.\t concentrations much below those necessary to pro- 
hibit electrolysis the action is similar to that obtained by 
adding a neutral electrolyte to the water, i.e., the electro- 
lytic effects are localised if not stimulated. There should 
be many cases, however, where the property of alkalis to 
inhibit corrosion could be made of more practical u.se than 
has been done. Whenever iron posts or standards are 
set directly in the ground instead of being embedded in 
concrete, the liberal use of slaked lime should be beneficial. 
The expedient of using metallic zinc in boilers to over- 
come the local slectrolytic effects in the iron by producing 
a still greater electrolytic effect at the almost exclusive 
expense of the more positive zinc is well known and has 
been in use for a long time. Although the theory on 
which the use of zinc for this purpose is based is sound, 
great difficulty has been encountered in maintaining good 
metallic contacts between sufficiently large surfaces of the 
two metals under the conditions which maintain in a boiler. 
From what has been shown in regard to the inhibitive 
action of the chromates it is not improbable, since such 
dilute solutions prevent electrolysis and corrosion, that 
the addition of small quantities of bichromate to boiler 
waters would be highly efficacious in preventing the rapid 
pitting which has caused so much trouble. It has lately 
been reported that steel boiler tubes used on vessels fitted 
with turbine engines suffered corrosion to the point of 
failure in from two to four months' service (Eng. Ne7cs, 
1907, Ivii., 426). This was found to be due to the fact 
that the steam, containing perhaps volatile acids, im- 
pinging on the bronze turbine blade, carried copper into 
solution and through the condensers into the boiler. Since 
iron does not change places with copper in dilute solution 
containing bichromate, it is possible that here again this 
salt would be found of practical value. That this state- 
ment is correct can easily be shown. If a bright piece of 
iron is immersed in a solution of copper sulphate so dilute 
as to show only a faint bluish tinge, the iron will never- 
theless turn dark from precipitated copper in a very few 
moments. If now potassium bichromate is added in only 
just sufficient amount to give a yellowish instead of a 
bluish tinge to the solution, iron will remain bright and 
copper will not be deposited. 

The experiment has been made by the writer of keeping 
iron and steel in dilute boiling solutions of bichromate for 
protracted periods at the same time that a current of air 
was bubbling through the boiler, and as long as the 
strength of the solution was equal to or above one-one 
hundred and sixtieth normal no rusting has ever taken 
place. Since this strength is approximately equivalent to 
one pound of the salt in 1500 gallons of water, there seems 
to be no reason why potassium bichromate should not 
come into use as a boiler protective. The application of 
the various inhibitors in the priming coats of paints and 
other protective coverings has already been to some extent 
made use of, and it would appear that slightly soluble 
chromates should be theoretically the best protectives for. 
the first application to iron and steel surfaces. 



40 



Thermo-chemistry of Phosphorus. 



I Chemical News, 
\ Jan. 22, 1909 



A very widespread impression prevails that charcoal iron 
and puddled wrought-iron are more resistant to corrosion 
than steel manufactured by the Bessemer and open-hearth 
processes. It is by no means certain that this is invari- 
ably the case, but it would follow from the electrolytic 
theory that in order to have the highest resistance to cor- 
rosion a metal should either be as free as possible from 
certain impurities, such as manganese, or should be so 
homogeneous as not to retain localised positive and nega- 
tive nodes for a long time without change. Under the 
first condition the irons would seem to have the advantage, 
but under the second much would depend upon care 
exercised in manufacture, whatever process was used. 

The evidence appears to be conclusive that the corrosion 
of iron in all its forms is primarily due to hydrogen ions. 
The ability of various samples to resist the attack of an 
acid of a standard strength may turn out to bear some 
relation to resistance to corrosion under service conditions. 
A great variation in resistance to acid corrosion is shown 
by different specimens of both iron and steel. An investi- 
gation of this subject is being made in connection with the 
work of Committee U of the American Society for Testing 
Materials. Carelessly made and poorly segregated metal 
will be easily attacked, no matter what it may be called 
or what method was used in its manufacture. As has 
already been pointed out, there are two lines of advance 
by which we may hope to meet the difficulties attendant 
upon rapid corrosion. One is by the manufacture of 
better metal, and the other is by the use of inhibitors and 
protective coverings. Although it is true that laboratory 
tests are frequently unsuccessful in imitating the conditions 
in service, it nevertheless appears that chromic acid and 
its salts should under certain circumstances come into use 
to inhibit extremely rapid corrosion by electrolysis. 



THE THERMO-CHEMISTRY OF PHOSPHORUS. 

By J. C. THOMLINSON, B.Sc. 

Among the data from which I contributed an article on 
this subject in the Chemical News (vol. .\cv., p. ), are 
given the following for the two allotropic forms of phos- 
phorus, P2O5 : — 

Thermal value (cals.). 
Ordinary yellow phosphorus . . . . 36g'9oo 
Red phosphorus produced by heating 

ordinary to 580^^ 326-860 

Ordinary red phosphorus 362-820 

Red phosphorus produced by heating 
ordinary to 360° 345'340 

The heat of combustion of ordinary yellow and red 
phosphorus are approximately the same, the average of the 
two being 365-910 cals. 

In that article I consider that phosphorus behaving as a 
qiiadrivalent element would have a heat of combination 
P;^ = 32-025 cals., and oxygen as a monovalent element 
7I-228 cals., when di-valent 52-545 cals. 

Applied to the two special cases of phosphorus under- 
going allotropic modification at definite temperatures, we 
may arrive at some conclusion as to how these values for 
valency and the combining powers (heats of combination) 
of the elements may be applied to the mechanism of 
chemical change. 

I propose to consider phosphorus as taking a quadri- 
valent part in combustion, and oxygen as having a variable 
valency in the cases given. In the combustion of ordinary 
red and yellow phosphorus representing three atoms of 
oxygen as divalent, and two as mono-valent, we get a 
calculated heat of combustion, 364-141 cals., the experi- 
mental value as given above being 365-910 cals., the whole 
reaction of combustion being represented by the formula — 

0==P_0-P^° 



The modification prepared at 360"^ gives a heat of com. 
bustion 345-340 cals., and representing the reaction in a 
similar way by the following formula we obtain a calculated 
heat of combustion 345-458 cals., — 



■P— O— P 



=0 

^o- 



Finally, in red phosphorus prepared at 580° the heat of 
combustion is 326860 cals., and with the slight departure 
from the above of regarding phosphorus as pentavalent 
(viiie vol. xcv.), P^J = 31-340 cals., and oxygen as di- 
valent, we get a calculated heat of combustion 327-405 
cals., — 

The above formulae represent the process of chemical 
reaction, as, of course, the final product phosphorus 
pentoxide is the same in each case. 

January 7, igog. 



THE OSMOTIC PRESSURE OF 

CON'CENTRATED SOLUTIONS, AND THE LAWS 

OF THE PERFECT SOLUTION.* 

By GILBERT NEWTON LEWIS. 

The laws of the infinitely dilute solution have been 
thoroughly established. There can be no reasonable 
doubt as to the accuracy of Henry's law for the vapour 
pressure of the solute, Raoult's law for the vapour pressure 
of the solvent, or van 't Hoff's law for the osmotic pressure, 
in the case of an infinitely dilute solution. In fact, if any 
one of these laws is shown to be correct, the other two 
must follow as a direct consequence of the laws of thermo- 
dynamics. 

Unfortunately, we never work with an infinitely dilute 
solution, and too little attention has been given to the 
question of the validity or even the mutual compatibility 
of the laws just mentioned in concentrated solutions and 
even in the so-called dilute solutions. 

There is a well known thermodynamic relation between 
the osmotic pressure of a solution and the lowering of the 
vapour pressure of the solvent, which enables us, in every 
case, regardless of the concentration of the solution, to 
calculate the osmotic pressure when the vapour pressure 
lowering is known, and vice versa. It is therefore pos- 
sible to calculate the osmotic pressure of a given solution, 
first, on the assumption that van 't Hoff's lawf is correct, 
and second on the assumption that Raoult's lawj is correct. 
It is commonly supposed that for fairly dilute solutions 
these two methods of calculating the osmotic pressure give 
identical results, but this is not the case. For example, 
the osmotic pressures calculated in these two ways for a 
normal solution of cane-sugar differ by 20 per cent, and 
even at the dilution of 0-005 normal the difference is still 
o-i per cent. It is obvious, therefore, that even in that 
region to which we are accustomed to apply the term 
" dilute solution," the law of Raoult and the law of van 't 
Hoff are not compatible. If one is true, the other must 
be false. What then shall we regard as an ideal or perfect 
solution ; one that obeys the law of Raoult or one that 
obeys the law of van 't Hoff, or shall we choose another 
criterion which differs from both of these ? 

Morse and Frazer (Am. Chetn. yotirn., 1905, xxxiv., i ; 
xxxvii.,324,425,558; i907,xxxviii., 175), who have recently 
succeeded in measuring osmotic pressures up to 25 atmos- 
pheres by a direct method, propose to replace the law of 



* From the lounial of the American Chemical Society, xxx., No. 5- 
\ II = «RT/Vi where II is the osmotic pressure, R the gas constant. 
T the absolute temperature, and n is the number of mols. of solute 
dissolved in the volume V of the solution. 

t (Po-P)lpo=niH» + Hi)f where ^0 is the vapour pressure of the sol- 
vent in the pure state, p that of the solvent from the solution, and »n 
is the number of mols. of solute dissolved in n mols. of solvent. 



Chemical Nkvvs, ' 
Jan. 22, igog i 



Osmotic Pressure of Concentrated Solutions. 



41 



n --- 



van 't Hoff by the following equation, which gives values 
for the osmotic pressure more in accord with those obtained 
experimentally in the case of sugar and glucose : — 

;iRT 

V 

Here V is not the volume of solution but the volume of 
pure solvent in which n mols. of solute are dissolved. 
These authors propose, therefore, to substitute for the 
system in which concentrations are expressed in mols. of 
solute in one litre of solution (volume normal system) 
another in which concentrations are expressed in mols. of 
solute dissolved in one litre of pure solvent (weight normal 
system). In most cases the difference between these two 
systems is much less than it is in the case of the two sub- 
stances of high molecular weight investigated by Morse 
and Frazer. Thus a weight normal solution of sugar is 
only 0-82 volume normal, a difference of about 20 per 
cent, but in the case of methyl alcohol, ammonia, and 
hydrochloric acid, substances of small molecular weight 
sslected at random for this calculation, the difference in 
concentration of weight normal and volume normal amounts 
to only 2, 4, and 2 per cent respectively. It is fortunate, 
however, that they did study those very substances in 
which the difference between the two systems is most pro- 
nounced, for we are thus forced to face certain questions 
concerning moderately dilute solutions which have been 
too often evaded. 

It will be the purpose of this paper not only to find what 
theoretical justification there may be for the above modifi- 
cation of the van 't Hoff equation, but also to determine 
in general which of the various laws of solutions may be 
most suitably chosen to define the perfect solution. 

Before beginning this inquiry it may be well to discuss 
briefly another question raised by Morse and Frazer, who 
write with some disparagement of the methods of deter- 
mining osmotic pressure which rest upon thermodynamic 
calculations. Without undervaluing in any degree the 
importance of direct measurements of a quantity which 
has played so important a part in the development of 
modern chemistry as osmotic pressure, it must nevertheless 
be definitely affirmed that we have at our disposal several 
means of determining the osmotic pressure which are 
readily capable of furnishing results many times as accurate 
as any yet obtained by direct measurement. These 
methods will, therefore, be briefly considered in the 
following section : — 

Direct and Indirect Osmotic Pressure Measurements. 

The exact definition of osmotic pressure, and some of 
the thermodynamic relations in which the osmotic pressure 
is involved will be discussed briefly in notes at the end of 
this paper. There it will be shown that the osmotic 
pressure of an aqueous solution may be obtained at once 
from the freezing-point by means of the equation — 

n = i2-o6A-o-02iA* . . . . i; 

where n is the osmotic pressure in atmospheres and A is 
the lowering of the freezing-point in centigrade degrees. 

(Note. — If we assume that at infinite dilution van 't 
Hoff's law holds exactly, and take R =0-08207 l»tre atmos- 
pheres per degree, from the work of D. Berthelot i^Zeit. 
Elektrochcm., 1904, x., 621), then we find from Equation i 
that the molecular lowering of the freezing-point of any 
aqueous solution at infinite dilution is 1-858°, which differs 
materially from the value commonly used, namely, 1-85. 
The latter value is used by Morse and Frazer, but they 
should use the value 1-843, for they do not employ the 
international atomic weights but those based on hydrogen 
as unity. The mol. is therefore reckoned in the latter 
system, and not in the customary one, in Tables I. and II. 
where Morse and Frazer's data are used). 

From this equation the osmotic pressure of any solution 
up to ten or fifteen times normal may be obtained with an 
accuracy which depends only upon the precision of the 
freezing-point determinations and upon the accuracy of the 



value used for the heat of fusion of ice. Since the error in 
the latter quantity is probably not more than about 01 per 
cent, it is obvious that, except for the most dilute solutions, 
osmotic pressures may be found in this way with an 
accuracy which is more than ten times as great as Motse 
and Frazer claim for their direct measurements. It is 
interesting to compare the osmotic pressures obtained by 
Morse and Frazer with those calculated by Equation i 
from the freezing-point measurement of the same authors. 
This comparison is made in Tables I. and II. The first 
column gives M, the number of mols. of solute in i litre 
of water, the second the lowering of the freezing-point, 
the third the osmotic pressure directly measured, the 
fourth that calculated from .1, and the fifth gives in round 
numbers the percentage difference between the observed 
and calculated values. In Table I., I have also given 
(below the line) the osmotic pressure of cane-sugar solu- 
tions calculated from the freezing-point measurements of 
Ewan {Zeit. Phys. Chem., 1899, xxxi., 22). These seem 
in perfect accord with the values of Morse and Frazer, and 
extend to higher concentrations. It is to be noted that 
each calculated value is obtained for the temperature at 
which the solution in question freezes, while the observed 
values were found at a few tenths of a degree above zero, 
but the correction for this small temperature difference is 
too small in comparison with the experimental errors to 
be considered. 

Table I. — Cane-sugar. 











Per cent 


M. 


d. 


nobs. 


n calc. 


differencf 


O'l 


0-195 


2*44 


2-35 


4 


0*2 


0-392 


4-80 


473 


1 


0-3 


0-585 


7-16 


7-05 


2 


0-4 


0-784 


9 40 


9 "45 


I 


0-5 


0-985 


II-8 


11-8 





0-6 


1-19 


14-2 


143 


I 


07 


1-39 


i6-8 


i6-7 





0-8 


1-62 


19-3 


19-5 


I 


09 


1-83 


22-1 


220 





i-o 


2-07 


24-8 


249 





0-867 


1-77 


— 


21-3 





1-25 


2-68 


— 


32-2 





1-54 


3-42 


— 


41-0 





1-63 


3-63 


— 


43-5 





2-10 


4-88 
Table 


U.— Glucose 


58-4 




O'l 


0*t92 


2*40 


3-32 


3 


0*2 


0-386 


4-65 


4-65 





0-3 


0-576 


7-01 


694 


I 


0-4 


0-762 


9-30 


9-18 


I 


0-5 


0-952 


11-6 


"•5 


I 


0-6 


I-I5 


14-0 


13-8 


I 


0-7 


1-34 


16-4 


16-1 


2 


0-8 


1-53 


18-8 


18-4 


2 


0-9 


1-72 


21-2 


20-7 


2 


i-o 


1-92 


23-6 


231 


2 



It is apparent that the observed and calculated values 
for the osmotic pressure agree within the limits of error of 
the former. The tables indicate, moreover, that the 
experiments with glucose were somewhat less reliable than 
those with cane-sugar. 

Since, therefore, freezing-point measurements offer a 
simple and exact means of determining the osmotic pres- 
sure at the freezing-point, it is possible from them to deter- 
mine the osmotic pressure at other temperatures, if we 
know its temperature coefficient. Morse and PVazer have 
considered it impossible to predict the value of this coeffi- 
cient, but they have overlooked the simple thermodynamic 
equation, which may be derived immediately from the 
familiar energy equation of Helmholtz, namely, — 

n-q^T^ ....... 2; 

where n is the osmotic pressure, 1 the absolute tempera- 



42 



Volumetric Method for the Determination of Barium. 



/Chemical News, 
1 Jan. 22, lyog 



ture, and q is the heat of dilution ; that is the heat evolved 
when I cc. of solvent is added to a large quantity of the 
solution. This quantity q is known for a large number of 
solutions, and in any case may be very easily determined. 
For cane-sugar we have very accurate knowledge of this 
quantity for one temperature, 15°, from the independent 
but entirely accordant work of von Stackelberg (Zcit. Phys. 
Chein., 1898, xxvi., 533) and Ewan [loc. cit.). According 
to their measurements in the case of a weight normal 
solution q is equal to 0-12 cal. or 5 cc.-atmos. Sub- 
stituting the latter value in Equation 2 and calling n at 
15° approximately 24 atmos., which according to the 
experiments of Morse and Frazer cannot be far wrong, we 
find— 

rfT 273 + 15' 
or about 007 atmos. per degree. In other words, while 
the osmotic pressure of an ideal solution at is*" changes 
0-35 per cent per degree, the normal sugar solution changes 
only 0-27 per cent per degree. Unfortunately we do not 
know the heat of dilution of sugar solutions at lower tem- 
peratures, but since in other cases von Stackelberg has 
shown that it increases with decreasing temperature, it is 
probable that it does in this case also. The temperature 
coefficient of osmotic pressure will therefore probably 
become smaller at lower temperatures and may even 
become negative (when 7 > n), which would explain the 
surprising lact discovered by Morse and Frazer that the 
osmotic pressure of cane-sugar is about the same at 0° as 
it is at 25°. 

Since the heat of dilution may be very readily measured 
at any temperature, we have by its means a remarkably 
simple method of determining the osmotic pressure at any 
temperature, if it is known at one. 

For obtaining the osmotic pressure of a solution at any 
temperature there is another perfectly general indirect 
method which has been frequently employed (see, for 
example, Noyes and Abbott, Zeit. Phys. Chem., 1897, 
xxiii., 56) and recently has been improved to such a point 
that it rivals in accuracy the freezing-point method (see 
Smits, Zeit. Phys. Chem., 1905, li., 33). It depends upon 
the thermodynamic relation between the vapour pressure 
from a solution and the osmotic pressure, which may be 
expressed in the equation (for the development of this 
equation, see Note 3, at the end of this paper) — 

Here n is again the osmotic pressure, a is the coefficient 
of compressibility of the solvent, Vo is its molecular volume, 
In stands for natural logarithm, and />o and p are respec- 
tively the vapour pressure of the solvent in the pure state 
and in the solution. Several applications of this equation 
will be made in the following section. 
(To be continued). 



A VOLUMETRIC METHOD 

FOR THE DETERMINATION OF BARIUM. 

By ARTHUR E. HILL and WILLIAM A. H. ZINK. 

Introduction. — Volumetric methods for the determination 
of barium appear to be few in number and somewhat 
limited in application. Sutton enumerates five methods in 
all, of which the best known is probably the direct titration 
of the barium compound in alkaline solution with 
standardised potassium dichromate until the supernatant 
liquid assumes a yellow colour (" Sutton's Volumetric 
Analysis," 1904, p. 161). The precipitate may also be 
filtered and washed, reduced by a measured excess of a 
ferrous salt, and the residual ferrous iron titrated with 
potassium permanganate {Ibid., p. 162) ; see also Mohr, 
"Titrirmethode," Braunschweig, 1886, p. 346). Barium 
hydroxide or carbonate may be titrated directly with 



standardised acid {Ibid., p. 69), while the neutral salts 
may either be titrated with sodium carbonate, using 
phenolphthalein as indicator {Ibid., p. 6g), or may be pre- 
cipitated with ammonium hydroxide and carbonate and 
the washed barium carbonate titrated with standardised 
acid {Ibid., p. 70). The new method here proposed 
depends upon the precipitation of barium as iodate and 
upon the oxidising action of this compound upon an iodide 
solution, with subsequent titration of the ree iodine with 
sodium thiosulphate. 

Discussion of tlie Method. — The solubility of barium 
iodate in pure water is given as 0-028 grm. of salt, or about 
8 mgrms. of barium per 100 cc. of solution at 25^ (Trantz 
and Anschutz, Zcit. Phys. Chem., 1906, Ivi., 238), an 
amount too large to admit treatment of the compound as 
an insoluble salt. In accordance with the theory 01 
electrolytic dissociation, however, it might be expected 
that the solubility could be reduced to a negligible amount 
by the presence of a sufficient excess of a soluble iodate, 
provided that the barium iodate approximates complete dis- 
sociation when in saturated solution. A series of experiments 
showed that the desired condition is realised in neutral or 
alkaline solution when an excess of potassium iodate is 
used amounting to one-fiftieth formula weight per litre. 
Under these conditions the barium is so completely pre- 
cipitated that 100 cc. of the filtrate show no turbidity upon 
being warmed with sulphuric acid. It was found that the 
solubility of the salt was increased slightly by the presence 
of other compounds, for which reason a concentration of 
iodate twice that stated above is recommended in carrying 
out the analysis. 

The properties of the precipitated barium iodate are 
almost ideal for analytical work. It forms a white 
granular substance, settling quickly, and leaving a per- 
fectly clear liquid above ; the precipitation is complete 
within five minutes, if the mixture is well stirred. The 
granules are of sufficient size to filter easily without choking 
the paper, and a second filtration is but very rarely neces- 
sary. In these respects the compound is in marked 
contrast with other barium salts, such as the sulphate, 
carbonate (Knofler, Ann., 1885, ccxxx., 345), and chromate, 
or with the insoluble salts of the alkaline-earth metals as a 
class, which almost without exception are difficult to 
handle, require special precautions during the precipitation, 
and usually necessitate repeated filtration for their complete 
removal from the filtrate. 

The critical point in the analysis of the barium iodate is 
its treatment after filtration. The precipitate cannot, of 
course, be washed with water, in which its solubility is far 
too great. Experiments were therefore conducted to 
ascertain whether a more suitable liquid for the washing 
could be found. Samples of freshly precipitated barium 
iodate were rotated at room temperature for twelve hours 
with the ordinary concentrated ammonia (sp. gr. ogo) and 
with 95 per cent alcohol respectively, with the results 
which follow : — 

Ba per 100 cc 
Mgrms. 
Solubility of Ba(I03)2 in 85 per cent alcohol. . 3-1 
Solubility of Ba(I03)2 in concentated NH4OH 5-6 
Solubility of 63(103)2 in water (Trantz and 

Anschutz, /of. cj<.) 80 

Either concentrated ammonia or alcohol would therefore 
be preferable to water for washing purposes. It proved 
impossible, however, to make direct use of alcohol since it 
precipitates even the water-soluble iodates, which choke 
the filter-paper, and cannot be removed by a reasonable 
number of washings. A modified procedure has therefore 
been adopted ; the precipitate is first washed a few times 
with concentrated ammonia, to remove the greater part of 
the excess iodate, and then finally subjected to several 
washings with alcohol. A series of test analyses was 
made to ascertain the extent to which this treatment might 
affect the accuracy of the results ; constant quantities of 
barium chloride solution were precipitated with excess of 
potassium iodate, and the precipitates washed with varying 



Chemical News, 
Jan. 22, 1909 



Volu?mtnc Method for the Determination of Barium 



43 



quantities of ammonium hydroxide and alcohol, and finally 
analysed according to the directions given later. 

NH4OH C>HsOH Ba taken. Ba found. 

washings. washings. Mgrms. " Mgrms. 

2 3 84'40 84-40 

3 3 84-40 84-42 

4 6 84-40 84-49 

5 3 84-40 84-24 
8 3 84-40 83-81 
3 8 84-40 84-03 

The results indicate that the precipitate is not sensibly 
aiifected by being washed with ammonia from three to four 
times, or with alcohol from three to six times ; when 
washed with ammonia five or more times, or with alcohol 
eight times, the precipitate loses slight but detectable 
amounts. In analysing barium solutions by this method it 
is therefore recommended to wash the precipitate three 
times with concentrated ammonia, and three to six times 
with 95 per cent alcohol. 

In order to test this point still further, the ammoniacal 
and alcoholic washings have been tested for barium in 
over 150 analyses made in the course of this investigation. 
These wa.shings averaged about 25 cc. of ammonia and 
30 cc. of alcohol in each analysis, corresponding to about 
8 cc. for each washing. The ammonia always contained 
slight traces of barium, which were estimated at from one- 
tenth to three-tenths of a mgrm. ; the alcohol in many 
cases contained no barium that could be detected, and in a 
ew cases traces that could hardly equal one-tenth of a 
mgrm. That the quantity of dissolved barium is less than 
its full solubility value in the respective solvents would be 
expected — first, because the potassium iodate used as pre- 
cipitant is still in contact with the barium iodate during the 
washings with ammonia, reducing the solubility of the 
precipitate, and secondly, because granular and crystalline 
precipitates such as the barium iodate are often slow in 
reaching their solubility equilibria. 

The method may best be described by the following 
specific directions for its use : — 

Directions for Use of the Method. — The solutions required 
or the analysis are an approximately one-sixth normal 
solution of potassium iodate (about 36 grms. per litre) and 
a one-tenth normal solution of sodium thiosulphate, 
standardised by any of the usual methods, preferably 
against a known iodate solution. The soluble barmm 
compound to be analysed is taken in an amount that will 
contain about 100 mgrms. of barium, brought into solution 
in a small beaker, and rendered neutral or faintly alkaline 
by addition of ammonium hydroxide, which should be free 
from carbonates. Water is added to make up the volume 
to about 60 to 70 cc. After calculating approximately the 
quantity of sixth-normal iodate solution necessary to pre- 
cipitate the barium, add this quantity together with an 
excess of 25 cc, stirring the mixture well, and running in 
the iodate in a fine stream. Stir the mixture briskly for 
one minute, and allow it to stand, with frequent stirring, 
for five minutes longer. Filter through a 7 cm. filter- 
paper, used either dry or filled in the usual manner with 
water to which a little potassium iodate has been added. 
During the filtration avoid spattering the liquid on the 
sides of the funnel, so that the subsequent washing may 
not be rendered more troublesome. Catch the filtrate 
in a clean beaker, and use portions of the clear liquid in 
transferring the precipitate to the paper ; use of a rubber- 
capped stirring-rod facilitates the operation. Wash the 
precipitate three times with concentrated ammonium 
hydroxide, filling the paper to its upper edge, and continue 
the washings three or four times with 95 per cent alcohol. 
Transfer the precipitate to a 500 cc. Erlenmeyer flask by 
perforating the paper and washing down the barium iodate 
with a stream of distilled water : finally add the washed 
filter-paper to the material in the flask. Add 50 cc. of a 
10 per cent solution of potassium iodide, which has pre- 
viously been treated with sodium amalgam or whose 
iodate content has been determined by a blank test. Add 



10 cc. of concentrated hydrochloric acid solution, cover the 
flask, and allow it to stand, with occasional shaking, for 
five minutes. Wash down the sides of the flask and 
titrate the free iodine with the standardised thiosulphate 
solution, using starch as indicator. Each molecule of 
thiosulphate used corresponds to one-twelfth atom of 
barium. 

The method as given above may be applied to solutions 
of barium as hydroxide, chloride, bromide, iodide, nitrate, 
and acetate, or other soluble salt of an organic acid. 
Sodium salts may be present in any amount, and mag- 
nesium, ammonium, or potassium salts in amounts up to 
one-half grm., calculated as chlorides. The modifications 
necessary when the latter salts are present in large 
amounts will be described in succeeding paragraphs. 

The following analyses indicate the accuracy of the 
method when applied to pure barium compounds. They 
were made with a solution of barium chloride whose 
barium content was determined by gravimetric analysis, 
except in the case of No. 3, which was made with an 
analysed solution of barium hydroxide. The thiosulphate 
solution was standardised against an analysed potassium 
iodate solution. The potassium iodate (Kahlbaum's C. P. 
preparation) was analysed by reduction to iodide by menns 
of a slight excess of sulphurous acid, the iodide precipitated 
with a slight excess of silver nitrate solution, and the silver 
iodide filtered on a Gooch crucible and dried to constant 
weight at 120°. 

No 



Mgrms. Ba taken. Mgrms. Ba found. 

1. 34-24 34-22 

2. 34-24 34-20 

3. 6i-i^ 6i-20 

4. 85-84 85-83 

5. 85-84 85-72 

6. 12008 120-15 



Error. 
—002 
— 004 
+ 0-06 
-o-oi 
-0-I2 
+ 017 

Effects of Foreign Bodies. Sodium Salts. — Analyses 01 
a barium chloride solution to which were added quantities 
of a sodium chloride solution varying from one-half grm. 
to 3 grms. showed that no modification of the method is 
made necessary by the presence of sodium salts. When 
the sodium salt amounts to as much as 2 or 3 grms. special 
care should be taken to stir the solution vigorously and 
continuously during the precipitation of the barium iodate, 
which will otherwise carry down small quantities of sodium 
iodate, giving rise to high values for the barium. 

Potassium Salts. — When present in amounts up to 
one-half grm., potassium chloride does not noticeably 
aff"ect the accuracy of the barium determination. When 
present in larger amounts, however, it gives rise to values 
for the barium which may be i to 2 mgrms. high. The 
high values are probably due to the occlusion of potassium 
iodate. This salt can of course only be occluded from the 
undissociated portion of the compound, which is probably 
very small in quantity in the dilute solution from which 
the barium iodate is precipitated ; when additional potas- 
sium salts are added, however, the dissociation is reduced 
and there is greater opportunity for the occlusion to occur. 
This occlusion can be prevented by carrying out the pre- 
cipitation in hot solution. The faintly alkaline barium 
solution is heated nearly to boiling and the calculated 
excess of potassium iodate added in a thin stream, with 
constant stirring. The stirring should be continuous 
during the first one or two minutes, while the greater part 
of the precipitate is forming, after which the solution may 
be allowed to come slowly to room temperature or may 
even be cooled more quickly by immersion of the beaker 
in cold water. Frequent stirring is essential, whichever 
method of cooling be adopted, as small amounts of barium 
iodate will remain unprecipitated even after long standing, 
if the solution is left in quiet. When fully cooled, the 
mixture is filtered and the precipitate analysed as usual. 
Under the above conditions of precipitation the barium 
iodate forms a mass of gritty, glass-like crystals, whose 
rate of solution in hydrochloric acid is much slower than 
that of the softer and finer material formed by precipitation 



44 



Rarer Alkaloids of the Cinchona Group. 



Chemical News, 
Jan. 22, igog 



in the cold. In order to avoid error from this source, the 
washed precipitate should be transferred to the Erlen- 
meyer flask with a rather small quantity of water, so as to 
avoid excessive dilution of the acid, and after addition of 
the potassium iodide and the hydrochloric acid the mixture 
should be shaken thoroughly until no particles of undis- 
solved precipitate can be seen upon the bottom of the flask. 
Titration with thiosulphate before the oxidation of the 
iodide is complete is generally believed to give erroneous 
results. With the above modifications, the method may 
be applied to any mixture of barium and potassium salts. 
Analysis No. 4 in the following table was conducted in 
this way, while No. 3, in which only one-half grm. of 
potassium chloride was present, was carried out without 
this modification. 

Ammonium Compounds. — Ammonium salts exert a slight 
solvent action upon the barium iodate, even when the 
acidity due to their hydrolysis has been overcome by 
addition of ammonium hydroxide, while the latter com- 
pound decreases the solubility of the barium salt, as solu- 
bility determinations have shown. Neither of these factors 
is of sufficient importance to affect the precipitation of the 
barium iodate measurably under the conditions of the 
method. It was found, however, that high results are 
obtained in the presence of large amounts of ammonium 
salts, just as with potassium salts, the compound occluded 
being presumably ammonium iodate. Precipitation from 
a hot solution, conducted as described in the preceding 
paragraph, reduces the occlusion below the limits of ana- 
lytical detection, as shown by Analysis No. 8. When the 
amount of ammonium salt is less than one-half grm., cal- 
culated as chloride, the precipitation may be carried out 
in the cold ; Analysis No. 7 was performed under these 
conditions. 

Magnesium Salts. — Magnesium salts affect the method 
in the same way as potassium and ammonium salts. The 
precipitation may be carried out in the cold when the 
magnesium salt amounts to less than one-half grm., calcu- 
lated as chloride ; when the amount is larger, precipitation 
from hot solution is necessary. A small quantity of am- 
monium chloride should always be added to the solution 
to prevent precipitation of magnesium hydroxide when the 
solution is rendered alkaline, and more particularly to 
prevent formation of this compound and consequent choking 
of the filter when the precipitate is washed with concen- 
trated ammonia. Analyses Nos. 9 and 10 illustrate the 
two methods of procedure. 

Other Compounds. — Calcium and strontium must not be 
present in the solution except in traces, since their iodates 
are also precipitated in part under the conditions of the 
analysis. Tests in the presence of other metals were not 
conducted, since the iodates of nearly all the heavy metals 
are insoluble in alkaline solution. The method works 
without error in the presence of the various acid radicles 
mentioned previously. 

The following table contains the results of specimen 
analyses conducted under the various conditions men- 
tioned in the preceding text ; they represent the average 
errors which occur when the barium solution contains 
other compounds. The solutions used in the analyses 
have been described previously. 

No. 

I. 
2. 
3- 
4- 
5- 
6, 

7- 
8. 

9- 
10. 

On the basis of a fairly large number of analyses, con- 
ducted under widely divergent conditions, it may be 



CompoundB present. 


Ba taken. 


Ba found. 


Error. 




Mgrms. 


Mgrms. 




0-5 grm. NaN03 . . . 


85-84 


85-96 


-f 0-12 


0"5 grm. NaC2H302 • . 


85-84 


86-41 


+o'57 


0-5 grm. KCl 


85-84 


85-95 


-f o-ii 


3-0 grms. KCl . . 


85-84 


85-92 


+ 008 


2'o grms. NaCl . . 


85-84 


85-88 


+ 0-04 


3*o grms, NaCl . • 


85-84 


86-o6 


-fO-22 


0-5 grm. NH4CI.. .. 


85-84 


85-44 


-0-40 


2-0 grms. NH4CI 


85-84 


85-49 


-0-35 


0-5 grm. MgCl2 . . . . 


85-84 


85-96 


+ 0-I2 


2-0 grms. MgCl2 . . . 


85-84 


85-40 


-0-44 



claimed that the method permits the determination of 
barium with an error not greater than a few tenths of a 
mgrm. in the hundred ; when pure barium salts are 
analysed, the error rarely amounts to more than a single 
tenth. The exceptional properties of the precipitate make 
the method of manipulation more convenient than any of 
the known volumetric methods. Two analyses can easily 
be conducted at the same time, and the average time 
required for their completion is about one hour and thirty 
minutes. — yonrnal of the American Chemical Society, 
xxxi., No. r. 



PROCEEDINGS OF SOCIETIES 

SOCIETY 01- CHEMICAL INDUSTRY. 
(London Section). 

Ordinary Meeting, yanuary .\th, 1909. 
Dr. J. Lewkowitsch in the Chair. 

"Some Rarer Alkaloids of the Cinchona Group." By 
B. F. Howard, F.I.C, and O. Chick. 

The first part of the paper is taken up with a study of the 
use of cinchonamine hydrochloride as a reagent for the 
gravimetric estimation and detection of nitrates, making 
use of the peculiar property of this alkaloid in forming an 
insoluble nitrate. The method of estimation of nitrates 
gravimetrically is as follows : — A large excess of cinchon- 
amine hydrochloride solution is added to the nitrate in 
solution, the mixture stirred, a little hydrochloric acid 
added, and allowed to stand for at least twelve hours. It 
is then filtered and washed with a minimum quantity of 
water, dried at 100" C, and weighed. This method was 
found to give good results in all cases in which it was 
tried, except in the case of nitrates of metals forming 
insoluble chlorides or oxychlorides. The second part 
describes determinations of specific rotation, molecular 
weight, and methoxy groups by Zeisel's method in the case 
of this alkaloid, and also cinchonicine, cupreine, quinicine, 
and concusconine. 

"A Physico-chemical Method Jor comparing the Anti- 
septic Value of Disinfectants." By Drs. S. B. Schryver 
and R. Lessing. 

The principle of the method consists in determining the 
inhibitory action of disinfectants on the rate of growth of 
bacteria, as measured by the rate of chemical change in 
the substrate. The latter consisted generally of a gelatin- 
peptone mixture, and the change was measured by deter- 
mining the electrical conductivity. For this purpose a 
specially constructed pair of electrodes was employed. As 
the bacteria develope the gelatin is gradually broken down 
into albumoses, peptoses, amino-acids, and finally into 
ammonia and fatty acids. All these substances have a 
higher electrical conductivity than the original solution. 
Experiments were carried out with the object of correlating 
the chemical and physical changes in the substrate, and 
also of determining the influence of the age of any 
particular culture, when making a sub-culture into the 
same medium. It was found that if a sub-culture is made 
at an early stage of incubation, the rate of change pro- 
duced in the substrate in the sub-culture was relatively 
slow ; if made, however, during a period of vigorous 
growth, this change was rapid, and practically independent 
of the amount of inoculating fluid used in making the sub- 
culture. The effect of various disinfectants, both on fresh 
cultures and sub-cultures, was also investigated. By com- 
paring the inhibitory effect of different substances, a 
measure could be obtained of their relative efficiency as 
disinfectants. 

"Reactions between Dyes and Fibres." By W. P. 
Dreaper and A. Wilson. 
Dyes which exhibit colour changes in the presence of 



Chemical News, I 
Jan. 22, 1909 I 



Standard of Radio-activity. 



45 



acids, such as methyl-orange or Congo-red, behave dif- 
ferently when dyed on fibres. On animal fibres this action 
is greatly retarded, and under some conditions is absent 
altogether. Increase of temperature may still further 
modify the normal reactions. On cellulose fibres the re- 
actions are much the same as in aqueous solutions, but 
they are modified by the presence of neutral salts. These 
reactions indicate a closer relationship between animal 
fibres and dyes than in the case of fibres of vegetable 
origin. The colour changes which take place with most 
dyes in the presence of concentrated acids are also retarded 
in the presence of animal fibres with both acid and basic 
dyes. 



FARADAY SOCIETY. 
Ordinary Meeting, December 21st, 1908. 

Dr. N. T, M. WiLSMORE in the Chair. 

Mr. E, a. Ashcrokt, A.M.Inst.C.E., M.I.E.E., read a 
paper on " The Influence of Cheap Electricity on Electrolytic 
and Electrothermal Industries." 

The extent of future developments of electro-chemical 
industries will depend on the limits to which the cost of 
electric energy can be reduced at suitable sites. In most 
cases an industry only becomes economically possible 
when the price of power has been reduced below a certain 
point, which varies more or less for every electro-chemical 
industry. The author discusses, in particular, the lowest 
possible limits of cost for the production of electricity from 
water-power, with special reference to conditions such as 
exist to-day in Norway. Some industries (the smelting of 
iron, the manufacture of lime nitrogen, and the complete 
treatment of complex sulphide ores may be instanced), to 
be worked commercially, will require a supply of energy at 
a cost of about £2 per kw.-year, and this "low-grade 
limit " in the opinion of the author can only be obtained 
from what he calls water-powers of Class I., namely, those 
in which natural conditions enable the development and 
regulation of power at a very low expenditure of capital 
— of the order £-j per E.H.P. capacity, including all 
necessaries up to the dynamo terminals. (The author 
estimates the corresponding figure at Niagara to have been 
not less than £30). The number of powers of Class I. are 
not very numerous, and their natural advantages will to some 
extent be neutralised by the values placed on the water- 
fights, but many examples exist, and the author gives full 
particulars of the cost of developing a concrete case in 
Norway of 7500 kw. capacity. This fall costs £"] 8s. to 
develop and equip, and current can be sold at £2 los. per 
kw.-year. It should be mentioned that at Meraker 
3000 H.P. has been sold for ;^i 14s., and at Notodden 
(both in Norway) for ^i 17s. per kw.-year. The second- 
best source of energy in bulk to-day is what the author 
calls waterfalls of Class II., namely, those where a high 
cost of regulation or development is necessary to bring the 
water to the place of consumption, and to ensure an even 
supply all the year round. From these electricity can be 
sold for about £"5 6s. per kw.-year, while the corresponding 
figures for oil engines, gas engines, and steam engines are 
given by the author as £^ 4s., £6 iSs., and £Z 6s. 6d. 
respectively. 

Mr. W. R. Cooper (communicated) pointed out that the 
cost of water-power was frequently what it would fetch, 
and that it could not be likely to have a fixed value. The 
price of water-power tended to rise, that from other sources 
tended to fall ; water-power should therefore be purchased 
outright by the consumers and not merely leased. 

Mr. Bertram Blount thought that the author had not 
done justice to sources of power other than water ; the 
notion that very cheap power was required for all electro- 
chemical industries was erroneous. He referred to the 
possibilities of electric zinc smelting among the industries 
requiring cheap power awaiting development. 

Mr. W. Murray Morrison was also of opinion that 



steam and gae power could be produced cheaper than 
stated by the author — the former, in some cases, for £-i 
per kw.-year. The author's Class II. water-power he con- 
sidered a bad specimen, and he further criticised in some 
detail other figures given in the paper. lie thought that 
not enough margin had been left for contingencies. The 
source of the capital was an important consideration that 
had not been discussed ; on it frequently depended the 
nature and cost of labour. No two schemes were alike, 
and every one must be considered on its merits, taking all 
conditions into consideration. 

Mr. L. Gaster pointed out that the Niagara plant had 
been designed for a far greater output than had up to the 
present been reached, and that therefore the limit of cost 
of production of power was far below the figures at present 
obtaining. He suggested the desirability of manufacturing 
such products as graphite and carborundum at European 
power centres. 

Mr. Charles Weiss drew attention to the conditions 
under which the water-powers in the Bavarian highlands 
were being developed. 

Dr. H. BoRNS referred to some of the disadvantages of 
many water-powers, such as inconstancy of supply. 

Prof. R. H. Smith also remarked on the ice difficulty, 
which was of frequent occurrence. He did not think it 
possible, in the case of water-powers, to reach the low 
figures given by the author, and he took exception to the 
allowances for depreciation made in the paper. 

Dr. E. Feilmann suggested that very cheap power-gas 
schemes might be developed in connection with the peat- 
fuel industry, and he thought that large-scale experiments 
were being made in this direction. 

Mr. E. A. AsHCROFT, in reply, said his principal 
purpose had been to draw attention to the very special 
kinds of water-power that were still available, although 
rare, and not to contrast the various modes of power pro- 
duction. His figures, to which he adhered, represented 
a probable average. The ice difficulties referred to did 
not exist in Norway. 

THE RONTGEN SOCIETY. 

About a year ago the Standards' Committee of the 
Riintgen Society, dealing with the problem of setting up a 
standard of radio-activity, recommended that the Gamma 
ray ionisation from i mgrm. of pure radium should be 
regarded as a standard and called a " unit of radio- 
activity." Mr. C. E. S. Phillips, F.R.S.E., a member of 
the Committee, was entrusted with the task of sealing up 
some small quantities of radium to be used as sub standards. 
At the meeting of the Society on January 7th last, Mr. 
Phillips read a paper on the subject, and formally pre- 
sented three sub-standards containing between them about 
o'5 mgrm. of RdBra. The Rontgen Society intends to 
lend these sub-standards to competent people who require 
them for measurements of radium in their possession, and 
thereby to minimise the possibility of fraud in the sale of 
expensive radium preparations. The work of preparing 
and sealing up these standards, as described by Mr. 
Phillips, was one of considerable difficulty. In the first 
place, he obtained about 05 grm. of pure precipitated 
silica, and this he washed, sifted, and bottled. One mgrm. 
of radium bromide was then obtained and tested against 
a nearly pure specimen of known weight. It was dissolved 
in water, a small quantity of the prepared silica added, 
and on the liquid being evaporated the dry powder re- 
maining consisted of silica particles coated with a layer of 
the radium bromide. The process was repeated with 
other small quantities of silica until scarcely any radio- 
activity could be detected from the inside of the vessel, 
and the silica was then mixed together and sealed into a 
glass tube. A carefully selected length of soda-glass 
capillary tubing was chosen for this purpose, and a small 
bulb blown at one end of it, the other end being shaped 
into a funnel. A spiral of thin platinum wire was intro- 



46 



Piwherite from Wtst AusLralia 



I Chemical News 
I Jan. 12, 1909 



duced into the tube to carry off any positive electrification, 
and the radium-coated silica was then dropped through 
the funnel into the bulb, after which the tube was exhausted 
and sealed off at the fine neck. After being subjected to 
prolonged annealing, the little bulbs were fitted into a 
suitable case and were ready for any of the purposes to 
which a standard might be put. In the course of the dis- 
cussion, Mr. F. H. Glew pointed out that Sir William 
Ramsay had recently made some experiments which 
tended to show that radium after a time appeared to lose 
its power to decompose water, and he (Mr. Glew) sug- 
gested that it would be well to have a standard of oxide of 
uranium kept just as jealously, and under the same con- 
ditions, as these radium standards. If, as might turn out 
to be the case, radium lost some of its properties more 
quickly than theory had predicted, there would at least be 
standards side by side with it with which comparisons 
could be made. Mr. Phillips said that several radio- 
active standards had already been set up. There was one 
at Vienna, another in America, and there was also an 
oxide of uranium standard. He agreed that it would be 
interesting to bring them all into line. In reply to other 
questions, he said that before definitely weighing the 
radium in these sub-standards he intended to wait for 
three months until they had reached a radio-active equi- 
librium, when they would be compared with the known 
weight of radium at Victoria University, Manchester. 



ROYAL SOCIETY OF NEW SOUTH WALES. 
General Monthly Meeting, November ^th, 1908. 

W. M. Hamlet, F.I.C, F.C.S., President, in the Chair. 

The following paper was read : — 

" Note on Pucherite jrom West Australia." By E. 
Griffiths, Caird Scholar, University of Sydney. (Com- 
municated by J. A. ScHOFiELD, Acting Professor of 
Chemistry, University of Sydney). 

The subject of this note was contained in a few grms. 
of concentrates from Niagara, W.A., forwarded by Mr. 
C. F. de J. Grut, M.A., B.E., of Kalgoorlie. It gave on 
analysis the following result : — Bi203, 7377 ; V2O5, 25-31 ; 
FeaOs, 0-36; P2O5, trace; residue (insol. in HCl) o-8i. 
The physical properties and composition of the mineral agree 
with those recorded in Dana's " System of Mineralogy" 
for the mineral Pucherite. This is believed to be the first 
recorded occurrence of pucherite in Australia. 

Remarks were made by Mr. W. J. Clijnies Ross and 
the President. 

Exhibits. 

Mr. Maiden brought under notice of members the 
poisoning of human beings by a climbing plant known as 
Rhus radicans or " Poison Ivy," from North America, and 
occasionally found in gardens in New South Wales. It is 
a really dangerous plant, causing acute skin irritation, and 
a perfectly harmless plant, Anipelopsis Veitchii, is often 
mistaken for it. He showed how the two plants may be 
readily distinguished. " Poison Ivy " is far too poisonous 
a plant to be permitted in gardens, especially as it is not 
necessary to actually touch it to be affected by it. He 
also exhibited a plant of the beautiful Primula obconica, 
and showed a photograph to illustrate the very serious 
skin irritation induced in some persons who handle it. He 
explained that the irritating principle in the case of the 
Primula is the glandular hairs ; in the case of the Rhus, 
known also as Poison Ivy, it is a peculiar oil. 

A Discussion ensued in which the following gentlemen 
took part, viz. : — The President, Messrs. L. Hargrave, 
W. J. Clunies Ross, Dr. Spencer, Messrs. J. A. Schofield, 
L. Whitfeld, H. G. Smith, and A. Duckworth. 

Mr. J. H. Maiden replied, and promised to bring forward 
the matter of some other poisonous garden plants on some 
future occasion. 



NOTICES OF BOOKS. 

The Nature of Enzyme Action. By W. M. Bayliss, 
D.Sc, F.R.S. London, New York, Bombay, and 
Calcutta : Longmans, Green, and Co. 1908. 
This volume is one of a series of monographs on biochemis- 
try which is to be issued under the joint editorship of 
Professors R. H. Aders Plimmer and F. G. Hopkins. In 
this series the whole of the science is to be covered, so 
that when it is brought to a conclusion the monographs 
will constitute a complete treatise on the subject. The 
issue in different books has much to recommend it. The 
publication can be effected far quicker than if one large 
volume were to be prepared, and, moreover, as fresh 
editions become necessary they can be published without a 
re-issue of the whole series, so that the difficulty of keeping 
the series up-to-date is considerably diminished. In such 
a rapidly growing subject as chemical physiology the 
advantages of the plan are specially apparent, and it has 
been found to be most successful in the case of the series 
of Text-books of Physical Chemistry edited by Sir William 
Ramsay. Each monograph is to contain a bibliography, 
and is to be complete in itself. The first volumes of the 
series are to deal more especially with the general aspects 
of the subject, and with the pure chemistry of physiological 
products, while the subsequent books are to be devoted to 
the chemistry of special tissues. This, the first volume to 
come under our notice, treats in a very efficient manner of 
the enzymes— their chemical and physical properties, 
methods of preparation, &c. ; details of the individual 
characteristics of specific enzymes are not included, the 
aim of the monograph being rather to supply a general 
review of the subject. The book is based upon lectures 
which were given by the author at University College, 
London ; these, however, have been contracted in some 
directions and expanded in others, as seemed necessary for 
the issue in book-form. The author's own work on the 
nature and action of enzymes has led to some important 
advances in our knowledge, but he by no means gives 
prominence to his own views, and displays the utmost 
broadmindedness towards opinions which are in opposition 
to his own. 



Cyanide Processes. By E. B. Wilson, E.M. Fourth 
Edition. New York : John Wiley and Sons. London: 
Chapman and Hall, Ltd. 1908. 

This book contains a very straightforward, simply worded 
account of the treatment of ore by the cyanide method, 
including the chemistry of the method, laboratory work 
necessary for testing the solutions employed, and a full 
description of the process. Detailed accounts of the 
machinery and apparatus are very wisely omitted, and the 
aim of the book is to give a clear presentment of the main 
features and principles of the process of cyaniding. In the 
fourth edition recent advances and improvements are de- 
scribed, special attention being devoted to the most modern 
methods of treating slimes. 

Text-book OT Physiological Chemistry. By Emil Abder 
halden. Translated by William T. Hall and George 
Defreu. New York: John Wiley and Sons. London 
Chapman and Hall, Ltd. 1908. 
This translation of a valuable German text-book on 
physiological chemistry must be at once recognised as a 
standard and authoritative text-book in which the most 
important results which have been obtained in physio- 
logical investigations are discussed in full detail. The 
first lectures deal with the three important classes of food 
substances, carbohydrates, fats, and albumins.first as regards 
their chemical composition, each class being treated sepa- 
rately. Their role and their metabolism in the organism 
are next discussed, and then their relations to one another 
and mutual replaceability are treated. The function and 
importance of inorganic foods is the subject of the following 



HKMICAL IVeUS, I 

Jan. 22, looq I 



Notices of Books. 



47 



ectures, and a short account is given of the nature and 
action of ferments. The functions of the digestive organs, 
the composition and character of the blood and lymph, and 
the quantitative study of metabolism are also discussed, 
and the two concluding lectures give a very clear and 
interesting survey more particularly of the problems which 
still remain to be solved. In these last chapters Ehrlich's 
side-chain theory, the outcome and true value of which 
can hardly yet be thoroughly realised, is given full con- 
sideration. 



Practical Metallurgy. By Thomas Turner, M.Sc, 
A.R.S.M., F.I.C.. London : Charles Griffin and Co., 
Ltd. 1908. 
In writing this book the author has had in mind more 
especially the requirements of candidates for the B.Sc. 
degree in metallurgy in the University of Birmingham ; for 
this examination a three years' course after matriculation 
is necessary, and in the first two years the student has to 
work through a general introduction to the more specialised 
metallurgical work. This two years' course of practical 
work is covered in the book, which treats shortly of the 
analysis of alloys, clays, slags, ores, &c. No descriptions 
of the methods or apparatus of elementary chemistry are 
given, and thus there is the more room for technical 
matter. Each section is complete in itself, and there 
would be no difficulty whatever in making any desired 
alterations in the order in which the different branches are 
taken up. The exact details of each process are carefully 
described, and the student should be able to work success- 
fully from the book with very little outside help. This, 
however, does not apply to the section on electrical work, 
which is discussed with extreme brevity, so that the con- 
sultation of other books would undoubtedly be found to be 
absolutely necessary. 

The Ne7c Matriculation Chemistry. By G. H. Bailey, 
D.Sc. (Lond.), Ph.D. (Heidelberg). Edited by William 
Briggs, LL.D., M.A., B.Sc, F.C.S. Fourth Edition. 
London : University Tutorial Press, Ltd. igo8. 
A FEW changes have been made in the fourth edition of 
the " Matriculation Chemistry," chiefly as regards the in- 
troductory section. This has been re-written by Mr. 
H. W. Bausor, M.A., and as it stands now provides the 
student with some training in practical work both qualita- 
tive and quantitative, while at the same time it gives him 
an insight into methods of scientific investigation. The 
outlines of chemical theory are also clearly treated in this 
section. The second part contains a systematic treatment 
of||the non-metals and metals, and in the third part the 
chemistry of daily life is discussed, the syllabus of the 
matriculation examination being carefully followed. The 
book can safely be recommended for students, who may 
feel confident that no point in the syllabus has been 
neglected ; indeed, in some cases for the sake of com- 
pleteness extra subjects have been included. No reference 
book on chemistry will be needed by those who use this 
book, and as an elementary treatise for ordinary school use 
it will be found in many ways by no means inferior to the 
majority of such books. 

Massing of Spheres. Part I. By G. J. Stevens. London : 

J. Haslam and Co., Ltd. igoS. 
In this pamphlet a rule or formula is given by which the exact 
atomic weights of all elements which can possibly exist are 
supposed to be obtained. By considering the structure of a 
compact mass of spheres it is found that in such a mass a 
series of measurements exists closely allied to the series of 
the atomic weights, and thus by triangulation it is possible 
to determine the dimensions of the elemental atoms, 
assuming that the radius of the ether sphere is unity. 
This process gives a succession of numbers which in some 
cases agree well with those representing the atomic weights 
of known elements. On the other hand, there are some- 
times considerable discrepancies, and the scheme, ingenious 



as it undoubtedly is, cannot by any means be described as 
convincing. The atomic weight of the ether is deduced to 
be I, and it is thus commensurable with the elements. 



Technical Chemists' Handbook. By George Lunge, 
Ph.D., Dr.lng. London: Gurney and Jackson. igo8. 
The German book of which this is a translation was 
originally intended for the use of alkali makers, and dealt 
only with the methods of analysis which are of special 
importance in alkali works. The latest German edition 
was extended to other important inorganic chemical in- 
dustries, and the additional matter included the description 
of the analysis of the raw materials and products in the 
manufacture of fertilisers, the analysis of calcium carbide, 
acetylene, &c. The English translation of this latest 
edition is a valuable laboratory guide for technical chemists. 
In it only one method is given of estimating each con- 
stituent, so that its general use among chemists would be 
a step in the direction of establishing a standard of com- 
parison accepted by all analysts. The first part of the 
book includes mathematical tables, tables of physical con- 
stants, and various mensuration formulae, while in the 
second brief descriptions are given of the best methods of 
analysing the raw materials, lye, and final products of the 
chief inorganic chemical industries. No methods of 
analysing foods and feeding stuffs are given, but otherwise 
the book forms a complete practical text-book of all ordinary 
technical analytical processes. 



Text-book of Physics. (Heat). By J. H. Povnting, 
Sc.D., F.R.S., and J. J. Thomson, M.A., F.R.S., 
Hon. Sc.D. (Dublin). Third Edition. London : Charles 
Griffin and Company, Ltd. igoS. 
This text-book of physics is too well known to need 
recommendation, although it may not be amiss to point 
out some of its special features. Chief among these is the 
emphasis laid on experimental work, which is fully described 
and discussed, with in many casesclear diagrammatic illus- 
trations. Moreover, examples of heat phenomena drawn 
from physiography are frequently instanced, while finally, 
none but the simplest mathematical processes are intro- 
duced, making the book specially suitable for students who 
have had only a very slight amount of training in mathe- 
matics. In the third edition a few mistakes which time 
and use have brought to light are corrected, and also some 
additions have been made relating chiefly to recent work. 



Collection of Papers Contributed on the Occasion of the 
Celebration of Professor jf. Sakurai''s yubilee. Tokyo : 
Reprinted from the jfournal of the College of Science. 
igoS. 
This collection of papers has been published in honour of 
the distinguished career of Prof. Joji Sakurai, of the 
University of Tokyo, who has made his name universally 
known as an original investigator, as a teacher, and as an 
author, more especially on subjects connected with physical 
chemistry. In addition, he has done much to promote 
educational and social reforms in Japan. The papers, 
written for the most part by his own pupils and describing 
researches carried out by them, form an admirable tribute 
to the inspiring and enthusiastic character of Prof. 
Sakurai's tutorial work. They are almost all published in 
English, the two exceptions being in German, and deal 
exclusively with chemical subjects. In every case a perfect 
lucidity of expression is displayed, and a very considerable 
command of the English language, any ambiguity or 
clumsiness of diction being altogether absent, though some 
misprints disfigure the articles in German. Possibly the 
papers which will attract the most attention are those 
describing the properties and preparation of the ne^v 
elements which have been discovered in thorianite, reinite, 
and molybdenite. The author of the paper, M. Ogawa, 
has isolated, firstly, an element of equivalent weight about 
50, to which he has given the name " Nipponium (Np)," 
suggested by Sir William Ramsay ; secondly, an element 



48 



Meetings for the Week. 



{Chemical News, 
Jan. 22, 1909 



closely allied to molybdenum and having an equivalent 
weight about 167 ; while there are also indications that 
thorianite contains yet another new element, the oxide of 
which is radio-active. 



Water : its Origin and Use. By William Coles-Finch. 

London : Alston Rivers, Ltd. 1908. 
Those teachers who think that a superficial knowledge of 
zoology and botany represents the best that is to be gained 
by " nature study " would do well to read this book written 
by an enthusiastic student of natural phenomena. As 
interesting as a novel and as instructive as a scientific 
treatise it may be said to rank as a romance dealing not 
with incidents or adventures, but with the development of 
character ; it is a true character study of water. The 
water of the atmosphere, rain, snow, ice, springs, and 
wells are all discussed in a most interesting way, the 
chapters on the clouds and on glaciers being particularly 
delightful. Some account is given of different methods of 
obtaining water, the sinking of wells, the construction of 
water works, and the preparation of water for consumption 
for domestic purposes. The uses of water for irrigation 
and for working hydraulic machines arc shortly discussed 
in the final chapter. To add to the charm of the book, it 
is illustrated by really beautiful pictures, those of mountain 
and glacier scenery having been reproduced from the 
originals of Mrs. Aubrey Le Blond. The author's hope 
that many who are not attracted by scientific works may 
find pleasure in this book we can sincerely echo, and add 
that the awakening of their interest in the wonders of 
nature through its instrumentality will undoubtedly be 
attended by genuine profit to themselves. 



A Scientific Viezv of Human Conduct. By George Gore, 
F.R.S., LL.D. Birmingham: Hudson and Woolston. 
1^08. 
This pamphlet endeavours to prove the existence of a 
scientific basis of human conduct which is regulated 
strictly on the same mechanical and mathematical plan 
as controls inanimate nature. The essential differences 
between dogmas and scientific principles are explained, 
the value of the former being admitted as preliminaries to 
knowledge ; thus they are looked upon as justified both 
by necessity and by their utility. Though the article con- 
tains no ideas of great novelty, yet possibly the truths are 
put forward in fresh aspects which will make them clearer 
to some readers, and the whole pamphlet is marked by a 
calm spirit of philosophical enquiry on a higher level and 
much more impressive than mere controversy. A short 
discussion of the reasons for the existence of pain and evil 
aims at showing that these are essential parts of the 
general scheme, acting in the direction of the good of the 
universe as a whole and not warring against it. 



Les Densites des Solutions Sucrces a Differeiites Tempt ra- 
tures. (" The Densities of Sugar Solutions at Different 
Temperatures"). By D. Sidersky. Brunswick : Friedr. 
Vicwcg und Sohn. Paris : H. Dunod and E. Pinat. 
igo8. 
The existing tables connecting the densities of sugar 
solutions with the amount of dry extract exhibit many 
discrepancies among themselves, some being calculated 
for a temperature of 17*5", and others for 15°, while 
German tables are referred to the density of water at xy5° 
or is'^ as unity, and French tables are based on the metric 
system. The correction for different temperatures is a 
matter of considerable complexity, and the deviations are 
often comparatively large. To remedy this state of affairs 
the author has calculated tables giving the dry extract of 
sugar solutions corresponding to densities observed at any 
temperature from 10° to 30°. An introduction giving a 
review of the different systems of tables in use is printed in 
two languages, the German text being on one page and 
the French opposite to it, and the book will undoubtedly 
be much appreciated by sugar chemists of both nationalities. 



ABC Five-figure Logarithms. By C. J. Woodward, 
B.Sc. London : E. and F. N. Spon, Ltd. ; Simpkin, 
Marshall, Hamilton, Kent, and Co., Ltd. New York : 
Spon and Chamberlain. Birmingham : Cornich Brothers, 
Ltd. igog. 
This little book of logarithms is wonderfully comprehen- 
sive and compact, and is well worth the price asked for it. 
Rules are given for using the tables, and these are so 
clearly stated that even the totally inexperienced will find 
no difficulty in performing all the ordinary operations with 
their help. The logarithms of arc functions are included, 
and many examples in crystallography, navigation, &c., 
are worked out. The lateral index, which enables the 
user to turn up at once any number he requires is a great 
convenience. A table of natural arc functions to each 
minute of angle has been added to the second edition, and 
on the covers indexes are given enabling the page on 
which a given logarithm of an arc function will be found 
to be determined rapidly. 



CHEMICAL NOTICES FROM FOREIGN 
SOURCES. 



Comptes Rendus Hebdomadaires des Seances de V Academic 
des Sciences. Vol. cxlvii.. No. 25, December 21, 1908. 
Synthesis of Ammonia by means of Peat, — H. 
Woltereck. — When peat is treated as described in th« 
author's previous communication [Comptes Rendus, cxlvi., 
125), and the nitrogen is determined in the residue, it is 
observed that the percentage found is always greater than 
the amount present in the original peat, after four hours' 
treatment. After six hours' treatment, on the other hand, 
the amount is decreased to half the original quantity. 

Humic Matter in Peat Moss. — L. Roger and E. 
Vulquin. — When peat is formed nitrogen and carbon 
accumulate in the degradation products of the plants. 
Neither pentosans nor hexosans are present in the humic 
matter. The alcoholic functions of the celluloses seem to 
persist, as shown by the formation of an acetylated com- 
pound and of a compound analogous to the thiocarbonate of 
cellulose. Several constituents of lignocellulose have been 
detected, an aromatic Cs radicle and a secondary acetyl 
constituent CH2CO. The unsaturated character of the latter 
is shown by the fixation of halogens. The humic matter 
also posseses acid properties. 



NOTES AND QUERIES. 

**• Our Notes and Queries column was opened for the purpose of giving 
and obtaining information likely to be of use to our retders generally. 
We cannot underidke to let this column be the means of transmitting 
merely private information, or such trade notices as should legitimately 
come in the advertisement columns. 

Specific Heats of Gases. -(Reply to J. Hewett). — These have not 
been re-determined recently. Consult " Pnysico-Chemical Tables," by 
J. Castell-Evans, p. 526 et seq. (published by C. Griffin and Co.) ; also 
" Annuaire pour I'An 1908," pp. 533—537 (published by the Bureau des 
Longitudes). 



MEETINGS FOR^THE WEEK. 

Monday, 25th. — Royal Society of Arts, S. (Cantor Lecture). " Public 
Supply of Electric Power in the United Kingdom," 
by G. L. Addenbrooke. 
TlesiDAY, 26th. — Royal Institution, 3. "Albinism in Man," by Prof. 

Karl Pearson, F.R.S. 
Wrdnesday, 27th.— Society of Dyers and Colourists, 8. "The 
Locust Bean and its Practical Application," 
by M. C. Lamb and F.J. Farrell. " Chlorinated 
Wool." by H. P. Pearson. 

Royal Society of Arts, 8. " Th« Part Played by 

Vermin in the Spread of Disease," by James 
Cantlie, M.A., &c. 
Thursday, 28th. -Royal Institution, 3. "Mysteries of Metals," by 
Prof. J. O. Arnold. 

Royal Society of Arts, 4.30. " Some Phases of 

Hinduism," by Krishna Gobinda Gupta. 
Friday, 29th. — Royal Institution, 9. " Improvements in Production 
and Application of Gun-cotton and Nitro-glycerin," 
by Col. Sir Frederick L. Nathan, R.A. 
Saturday, 30th. --Royal Institution, 3. " Sight and Seeing," by 
Prof. Sir Hubert Ton Herkomer, C.V.O., &c. 



Chemical News, 
Jan. 29, 1909 



Nature of the Alpha Particle. 



49 



THE CHE MICAL NEWS 

Vol XCIX., No. 2566. 



THE NATURE OF THE o PARTICLE. 
By Professor E. RUTHERFORD, F.R.S., and T. ROYDS, M.Sc. 

The nature of the a particle from radio-active substances 
has, for several years, been one of the most important 
questions in Radio-activity. The evidence as a whole 
indicates that the o particle is an atom of helium carrying 
a positive charge. Recent experiments of Rutherford and 
Geiger [Proc. Roy. Soc, 1908) have substantiated this 
conclusion. An additional proof of the correctness of this 
point of view is afforded by the good agreement between 
the rate of production of helium calculated by Rutherford 
and Geiger, and the rate of production recently measured 
by Sir James Dewar (Proc. Roy. Soc, igo8). 

This evidence is, however, of too indirect a character to 
prove decisively that the a particle is an atom of helium. 
It might be possible, for example, that the expulsion of an 
a particle led to the liberation of helium from the active 
matter, but that the a particle itself was not an atom of 
helium. In order to give a definite proof of the identity of 
the 1 particle with a helium atom, it is necessary to show 
that helium can be obtained from accumulated a particles, 
quite independently of the active matter from which they 
are expelled. This has been done in the following way : — 

Purified emanation, corresponding to the equilibrium 
amount from 150 mgrms. of radium, was compressed by 
raising a column of mercury into a fine glass tube about 
i"5 cm. long. The walls of this glass tube were suffi- 
ciently strong to withstand atmospheric pressure but thin 
enough to allow the greater part of the expelled a particles 
to be fired through them. After a number of trials, Mr. 
Baumbach succeeded in blowing a number of such fine 
tubes for us. The emanation tube was surrounded by 
a larger cylindrical glass tube about 8 cm. long and 
i"5 cm. diameter. This was first exhausted by a pump 
and the exhaustion completed by means of a charcoal tube 
immersed in liquid air. By means of another side tube 
connected with a mercury reservoir, the gases formed 
within the outside tube could be compressed into a small 
vacuum tube attached to the top and their spectra ex- 
amined. 

The tube containing emanation was about i/ioo mm. 
thick. The stopping power of the glass for the a particle 
corresponded to less than 2 cm. of air, so that the a par- 
ticles expelled from the emanation itself, radium A and 
radium C escaped through the emanation tube, and were 
fired into the walls of the outer glass tube. Twenty-four 
hours after the introduction of the emanation, no trace of 
helium was detected on compression of the gases into the 
vacuum tube ; at the end of two days the helium yellow 
line was seen faintly ; after four days, the yellow and 
green lines came out brightly, and after six days practically 
the whole helium spectrum was observed. 

An experiment was then made to test whether the 
helium observed could have disused from the emanation 
through the thin glass walls. For this purpose, the 
emanation was replaced by about ten times its volume of 
helium and a new outer tube and vacuum tube placed in 
position. No trace of helium was observed in the outer 
tube over a period of eight days. Emanation was again 
introduced, and after four days the helium spectrum was 
again observed. 

In these experiments every precaution was taken to 
prevent possible contamination of the apparatus with 
helium. Freshly distilled mercury and fresh glass ap- 
paratus was used. No trace of helium was observed unless 
the emanation was introduced into the fine capillary. 



This experiment affords a conclusive proof that the 
a particle after losing its charge is an atom of helium. 
Other evidence indicates that the positive charge on the a 
particle is twice that carried by the hydrogen atom. — 
Memoirs and Proceedings of the Manchester Literary and 
Philosophical Society, vol. liii., Part I. 



TANTALUM AND NIOBIUM IN AUSTRALIA. 

By EDWARD S. SIMPSON, B.E., F.C.S., 
of the Geological Survey of Western Australia. 

In the census of minerals of Australia submitted to the 
Australasian Association for the Advancement of Science 
in i8go no mention is made of any mineral containing 
tantalum and niobium. Since then, however, these 
rare metals have been recognised in several widely 
separated districts in the Commonwealth, and, in response 
to the recent commercial demand for tantalum ores, 
deposits of great richness and extent have been disclosed 
in the Pilbara Goldfield of Western Australia. In this 
paper an account will be given of the discovery of these 
interesting minerals in Australia, their mode of occurrence, 
and their chemical and physical characteristics. 

General Features of Occurrence. 

Before dealing with purely Australian deposits, it will 
be well to go briefly into the general features of the 
question. 

These two metals are nowhere found in the native state, 
nor in sulphide or other similar minerals, but exist always 
in combination with oxygen and one or more other metals, 
the oxides having an acid character, and giving rise to 
tantalates and niobates. They invariably occur in con- 
junction, replacing one another isomorphously to a very 
variable extent, the niobate of a metal often passing by 
insensible gradations into the tantalate without change oi 
form or physical characters other than a corresponding 
gradual rise in specific gravity, tantalum having an atomic 
weight double that of niobium. In this article, therefore, 
whenever a mineral is described as a tantalate it must be 
understood that it contains niobium as well as tantalum, 
but that the former is present in preponderating amount, 
and vice versa. 

The ores hitherto detected in Australia are : — 

1. Columbite, niobate of iron and manganese. 

2. Tantalite, tantalate of iron and manganese. The sub- 

species manganotantalite contains more manganese 
than iron ; the normal variety more iron than 
manganese. 

3. Stibiotantalite, tantalate of antimony. 

4. Microlite, tantalate of lime. 

5. Euxenite, titanoniobate of yttrium, erbium, cerium, &c. 

Until recently the best-known localities of the mineral 
tantalates and niobates were Sweden, Norway, Bavaria, 
Siberia, Greenland, and the United States. Though 
occasionally recorded as occurring in syenite rocks, the 
most usual primary occurrence in all these countries is in 
pegmatite veins in granite, especially in those characterised 
Ijy the presence of much albite. In these veins they are 
commonly accompanied by quartz, orthoclase, and mica, 
as well as albite, whilst garnet, zircon, topaz, monazite, 
cassiterite, and other uncommon minerals are often present. 
The only primary deposits described so far in Australia are 
those of Finniss River, (Northern Territory), Greenbushes 
(Western Australia), and the Wodgina District (Western 
Australia), all areas of granitic rocks. 

Most native tantalates and niobates offer considerable 
resistance to chemical change, and, being in the main both 
hard and tough, are of frequent occurrence in detrital 
deposits, though usually overlooked unless the latter 
happen to be worked for gold or tin. Still, there are 
numerous records of their detection in stream deposits in 



50 



Tantalum and Niobium in Australia. 



(Chbmical News, 
Jan. 29, 1909 



America, Siberia, and England, whilst detrital ores are of 
great importance in North-Western Australia. 

Within the last two years the search for these minerals 
has been greatly stimulated by the fact that they have 
suddenly become of considerable commercial value. This 
has been largely due to the discovery of the tantalum 
electric lamp, but partly also to the experiments being 
made with tantalum-steel alloys, which appear to possess 
many valuable properties. As much as 20s. per pound was 
paid in 1905 for bulk lots of high-grade tantalum ore. The 
price has, however, been very variable lately, ranging from 
about ;£'20o to ;£'iooo per ton, 

Queensland.— G^j'aW^OM. — The only record of any 
tantalum in this State is contained in publication No. ig6 
of the Geological Survey. A black sand occurring on the 
shore at the mouth of the Johnstone River, near Geraldton, 
was found on analysis to consist mainly of ilmenite (84 per 
cent). With it was 0*78 per cent of combined niobic and 
tantalic oxides, equal to 0*95 of tantalite or columbite. 
Which of these latter minerals was present is doubtful, as 
no separation of the oxides was made. The only other 
rarer minerals present were monazite and zircon. 

According to the 1902 geological map of Queensland, 
the watershed of the Johnstone River is occupied mainly 
by crystalline schists, with smaller areas of basalt. It is 
probably from the former — which may include granitic 
schists — or from offshoots of the large masses of granite 
lying further to the north and west, that the tantalite has 
been derived. 

New South Wales. — Ballina. — In Vol. VII. of the 
Records of the Geological Survey of this State there is a 
description of some tantaliferous concentrates from Broken 
Head, near Ballina. The original beach sand from which 
these were obtained was composed of quartz, zircon, 
ilmenite, with smaller proportions of monazite, cassiterite, 
iridosmine, and gold. The concentrates consisted of : — 
Monazite, 65 per cent; zircon, 22 per cent; cassiterite, 
9 per cent: and carried i* 10 per cent of tantalic oxide in 
one case and o"86 in another, equal to between i per cent 
and li per cent of tantalite. 

Euriowie. — In the early nineties Mr. C. W. Marsh re- 
ported the occurrence of columbite in association with 
cassiterite at the Euriowie Tinfield, near Broken Hill. A 
small specimen of this columbite, about 2in. long and fin. 
square, is in the Geological Museum in Sydney. It is too 
small to permit of an exact analysis being made, and there 
is some slight doubt as to whether it may not be euxenite 
(niobate and titanate of yttrium, &c ). Its specific gravity 
is said to be about 6, which supports the theory that the 
mineral is columbite. The tin lodes at Euriowie, according 
to Mr. Pitman, consist of a series of coarse pegmatite 
dykes, traversing gneiss and mica schist. The dykes are 
described as being composed of quartz, felspar, and mica. 
It would be interesting to know whether the felspar is 
mainly orthoclase or albite, as the latter is so characteristic 
of tantaliferous dykes. 

Silverton and Darling Range. — In a recent letter Mr. 
C. W. Marsh says: — "About two miles east of Silverton 
(Barrier Ranges) there is a large granitic outcrop, from 
which building stone has been quarried, having as 
accessory minerals tourmaline (black and red), ilmenite, 
garnets, and a little wolfram and columbite. I also 
remember finding columbite in granite at the southern point 
of the Darling Range, in the Rock Well Paddock, Barrier 
Ranges." 

Victoria. — So far no tantalum or niobium is known to 
occur in this State. A mineral discovered some years ago, 
and reported to be columbite, proved on further examina- 
tion to be rutile. 

South Australia. — As we leave the eastern side of 
Australia we find more frequent occurrences of these rare 
metals. 

Boolcomatto and Mount Babbage. — In the previously 
quoted letter of Mr. C. W. Marsh, that gentleman gives the 
following particulars with regard to discoveries made by 
him apparently between 1885 and 1895 : — " Sent from 



Broken Hill to Boolcomatto, S.A., to inspect supposed 
important tin find, which turned out to be a large granite 
outcrop, containing as accessory minerals ilmenite and 
tourmaline, with a little wolfram and columbite. 
Sent from Broken Hill to Mount Babbage, on the Northern 
end of the Flinders Ranges, S.A., to supposed valuable tin 
discovery, which turned out to be a deposit in creek bed 
consisting principally of dark garnets, with a little titanite 
and one large flat piece of columbite, with several small 
fragments of tantalite." 

Northern Territory. — In a report on the north- 
western district of the Northern Territory by Messrs. 
H. Y. L. Brown and H. Basedow, recently published by 
the South Australian Government, a short description is 
given of the occurrence of tantalum ores in that region. 
Three localities are mentioned, all within 30 miles of Port 
Darwin, in tin-bearing country. 

Finniss River. — This is apparently the only locality 
where tantalite is being raised for the market. The deposit 
was discovered twenty years ago, and worked for tin, the 
tantalite not being recognised as such until recently. As 
in so many other cases, it was — probably on account of its 
similar specific gravity — assumed to be identical with the tin 
ore which accompanied it. Messrs. Brown and Basedow 
described the deposit in the following terms : — " The ore- 
carrying body consists of a huge intrusion of greisen, 
trending south-westerly, with a slight underlie to the east. 
The outcrop measures from three to four chains in width, 
and about six chains in length. It is characterised by 
immense, compact, white inclusions of quartz. The 
texture of the matrix varies from abnormally coarse to 
sugary, the latter type of rock often containing epidote. 
Tantalite occurs practically throughout the mass, but is 
very erratic in its appearance as small bunches and isolated 
crystals. It assumes three modifications, depending largely 
upon the character of the enclosing matrix — firstly, as 
irregular inclusions in the compact white quartz, usually of 
a symmetrical outline or lamellar. In this form it occurs 
isolatedly, with no associated mineral. Secondly, as 
radial spherical crystal groupings in the rock of fine- 
grained texture. Thirdly, as regular rhombic crystal forms 
in a normal matrix, usually associated with tinstone. The 
country rock is an arenaceous mica schist. The main 
bulk of ore is obtained by surface work upon the decom- 
posed dyke and its sheddings on the hill slope." 

The ore in this locality is a mixture of cassiterite and 
mangano-tantalite, similar to that found at Wodgina, 
W.A., as shown by the following analyses taken from the 
report : — 



Tantalic oxide, Ta205 .. 41*70 

Niobic oxide, NbaOs . . . . i9"oo 

Tin oxide, SnOa 21-00 

Manganese protoxide, MnO 14*83 

Iron protoxide, FeO .. .. 2*14 

Undetermined 1*33 



55-52 
24*92 

4-40 
ii*i6 

273 

t*27 

100*00 100*00 

Bynoe Harbour. — Tantalum ore occurs as dyke dis- 
seminations on a mineral licence, nine miles south of the 
Leviathan Tin Mine, and also on Horden and PauH's 
claim, close to the other deposit. 

Port Darwin. — Tantalum ore is described as occurring 
in a similar manner six miles east of King's Table, West 
Arm of Port Darwin. 

Western Australia. — Moolyella. — This locality, ten 
miles north-east of Marble Bar, is chiefly of importance 
for the tin ores which are produced there. According to 
the report of Mr. A. Gibb Maitland the field lies in the 
midst of a large area of granite, which is intrusive into 
sedimentary rocks of probably Cambrian age. This granite 
is traversed by numerous dykes of a pegmatite composed 
mainly of quartz and albite, with subordinate mica, garnet, 
and cassiterite. Considerable quantities of stream tin are 
being obtained in this field, this ore being undoubtedly due 
to the disintegration of the pegmatite dykes. 



Chbmical Nbws, I 
Jan. 29, igog i 



Tantalum and Niobium in Australia. 



51 



In a parcel of stream tin ore in the museum of the 
Geological Survey of Western Australia is a single frag- 
ment of a mineral forming a quadrant of a sphere i in. in 
diameter, with radiated crystalline structure. This mineral 
is of an intense black colour, with a metallic lustre, and 
specific gravity 7*3. It is identical in appearance with 
some of the ore from Wodgina, and is without doubt 
manganotantalite. It is an aggregate of a number of 
wedge-shaped crystals, the mass parting readily along 
radial planes on being struck. Closely attached to its 
outer surface are numerous small fragments of quartz and 
several fragments of much altered albite. These indicate 
the original source of the mineral to have been those 
quartz-albite pegmatite veins which form the matrix of the 
cassiterite. 

Another similar, but smaller, fragment occurs in a second 
sample of stream tin ore, and others still smaller may easily 
have been overlooked. 

Cooglegong. — This tinfield occurs thirty miles to the south- 
west of Marble Bar. According to the researches of Mr. 
A. Gibb Maitland, it is situated in the midst of a large area 
of granite, which, in places, is gneissic. " The granite is 
intersected in certain localities by veins of pegmatite, which 
have doubtless been the original source from which the 
stream and residual tin have been derived." 

Gadolinite has been found both in the stream deposits 
and, associated with cassiterite and monazite, in a 
pegmatite vein. 

In a paper on this occurrence of gadolinite, read before 
the Royal Society of New South Wales, in October, 1902, 
Mr. B. F. Davis says : — "Amongst the minerals I brought 
from the north-west I have two varieties of a mineral allied 
to ' euxenite ' in physical characteristics, as described by 
Dana. One differs from the other in having more man- 
ganese in the place of uranium. They are essentially 
niobates and titanates (with tantalum) of uranium iron and 
yttrium earths, with cerium earths and thorium. They 
occur with cassiterite and monazite in the wash-dirt. I 
have only a few small pieces, but one mineral at least was 
not uncommon. I saw it in all the tin ore bagged from 
different parts of the country." 

Some of the mineral from this same locality, collected 
from samples of tin concentrates by Dr. McKenzie, of the 
Tin Smelting Works, Sydney, has been examined by Mr. 
D. Mawson, and found to be strongly radio-active. 

It is not, however, at all clear from Mr. Davis's paper 
whether this mineral was really obtained at Cooglegong or 
not. It may possibly have come from Moolyella. 

I have recently come across some specimens in the West 
Australian Museum, the locality of which is given as the 
Shaw River, so that they come either from Cooglegong or 
from the Old Shaw Tinfield a few miles out of Cooglegong. 
These specimens consist of a number of angular detrital 
fragments of typical euxenite, varying in size from 10 to 
40 mm. in length, and coated externally with a brown clay. 
On a fresh fracture the mineral is brown in colour, and 
possesses a brilliant resinous lustre. It has a specific 
gravity of 5-3. 

Thelemanu's Find. — Sixteen miles north-west of Lalla 
Rookh tantalum ore was obtained in igo6 by Mr. F. 
Thelemann. It is detrital ore, and is said to occur only in 
limited quantities. It is of little commercial value, being 
a low-grade iron columbite, assaying from 3 per cent to 
5 per cent of tantalic oxide. One sample, consisting of 
more or less worn fragments from a quarter to i inch in 
diameter, contained 4-92 per cent of tantalic oxide, 70-34 
per cent of niobic oxide, and no tin. The specific gravity 
of the constituent fragments was very uniform, averagings^s- 
The ore from this locality is frequently well crystallised. 
One good crystal measuring 7 x 23 x 30 mm., and having 
a specific gravity of 5'53, shows the following faces: — 
a, 100; b, 010 ; c, 001 ; u, 133 ; e, 021 ; m, no ; g, 130; 
y, 210. The lower half of this crystal has not developed, 
having apparently formed against an already crystallised 
mass of albite. Several other crystals, with fewer faces, 
have been collected from this locality. Many are not of 



the tabular habit of the crystal described. All are, how- 
ever, of low specific gravity, indicating a low tantalum 
content. One fragment has the radiated spherical structure 
previously mentioned in connection with Moolyella. The 
only associated minerals observed were quartz, tourmaline, 
and albite. Granite is the prevailing rock in the locality. 

Green's Well. — The main workings in this district are 
situated at a locality variously known as Green's Well, 
Mount York, and Chingamong. They were first developed 
in 1905, and are situated in the same belt of granite as 
extends from Thelemann's Find through Wodgina to 
Mount Francisco. 

The original mine in this locality has been described 
officially in the following terms : — "On M.L. 100 (O. T. 
Bell and party) a rubbly felspar formation has been ex- 
posed for a few feet. This carries tantalite, but sufficient 
work has not been done to allow of an opinion as to the 
richness of the lode. On McBeth's alluvial reward claim 
tantalite can be easily seen in the gully that traverses the 
claim." 

A sample of dressed ore from Green's Well, brought to 
Perth by Mr. A. Gibb Maitland, apparently consists of 
both stream and lode ore in angular fragments from i 
up to 20 mm. in diameter. A great portion of it is more 
or less well crystallised, a few excellent crystals being 
observed in it, of which the following are details : — 



No. 


Size in millimetres. 


Sp. gr. 


Faces observed. 


I, 


6 X 9 X 16 


6-31 


a, b, c, u. 


2. 


3 X 10 X II 


5-30 


a, b, c, M, e, y,m, g 


3- 


6 X 10 X 13 


6-49 


a, b, c, q, h (?). 


4- 


7 X 9 X 18 


6-05 


a, b, c, u. 


5- 


7 X 7 X 12 


6-32 


a, by c, u, k. 


6. 


II X 19 X 26 


577 


a, b, c, u, e, m. 



The sample, as a whole, assayed — tantalic oxide, 42*39 
per cent ; niobic oxide, 2i'09 per cent ; metallic tin, 15-62 
per cent. The mineral itself varies from a columbite, with 
specific gravity 5 •35, to a tantalite, with specific gravity 
6-84. tor the most part it has a dull rusty-black surface, 
but occasional crystals exhibit brilliant black metallic faces, 
especially a. This face and b is often striated vertically. 
The only associated mineral observed in any abundance is 
cassiterite. The primary deposit from which the ore is 
derived appears from the above description to be a typical 
quartz-albite pegmatite. 

The ore from Green's Well is characterised by the very 
variable extent to which tantalum and niobium replace one 
another. In another sample from here, individual crystals 
varied in specific gravity from 6*4 up to 7-9, indicating an 
approximate percentage of tantalic oxide varying from 
46 to 81. 

Wodgina. — By far the most important tantalum deposits 
in Australia are those of Wodgina, situated in the Pilbara 
Goldfield, in lat. 21" 15' S., long. 118° 40' E., 90 tons of 
dressed ore having already been shipped from this locality. 

In a recent article in the Mining Journal, Messrs. 
F. H. and W. A. Mitchell (the latter assayer at the Mons 
Cupri Copper Mine, 80 miles from Wodgina) make the 
following statement with regard to the first discovery of 
tantalum ore at Wodgina : — " This mineral was first ob- 
served by us in North- West Australia early in 1901, when 
a crystal was submitted to the British Museum authorities 
for confirmation ; but it was not until about four years 
later that we introduced this mineral into Europe for 
commercial purposes." 

In May, 1904, a black mineral from this locality wag 
forwarded for identification to the Acting Mineralogist and 
Assayer, Mr. C. G. Gibson, and proved to be mangano- 
tantalite, a preliminary analysis showing the presence of 
80 per cent of tantalic and niobic oxides and 16 per cent 
of manganese oxide. At that time there was no market 
for the mineral except for museum and other educational 
purposes, for which purpose the demand was limited to a 
few pounds per annum. Towards the end of the year, 
however, the demand which arose in connection with the 



52 



Osmotic Pressure of Concentrated Solutions. 



Chemical News, 
Jan. 29, 1909" 



manufacture of tantalum lamps stimulated prospecting for 
these minerals, and since then a great number of ores 
from all parts of the district have been examined in the 
laboratory attached to the Geological Survey of Western 
Australia. 

The locality has recently been geologically examined 
and mapped by Mr. Maitland, and from his report the 
following resumS of the structural features of the rock 
masses and ore bodies has been culled. 

The tantalum ores occur in stream deposits, in shallow 
surface detritus in the immediate vicinity of the outcrops 
of pegmatite dykes, and in these dykes themselves. They 
occur in a mass of hornblende-schist, and are apparently 
offshoots of a mass of granite lying at a short distance to 
the north, east, and south-east. Between the hornblende 
rock and the granite on the south-east are a series of 
schists of indeterminate origin, mostly very siliceous and 
carrying either mica or haematite. Their origin is still a 
matter of some speculation. Within the area of these 
schists the pegmatite veins are tin-bearing, and are being 
worked for that metal. 

The most important tantalum vein in Wodgina proper 
is that which passes through mining leases 86 and 87 in a 
north and south direction. It is from 30 ft. to 40 ft. wide, 
and consists of variable proportions of quartz, felspar 
(mainly albite), mica (muscovite and lepidolite), and tan- 
talite ; the last-named in crystalline masses from the size 
of shot up to 5 cwt. in weight. A little west of this main 
vein is a second smaller one of similar nature. From the 
outcrops of these veins a larger amount of ore has been 
shed, and the greater part of the ore hitherto exported has 
been obtained by "specking" and dryblowing the shallow 
detritus on the surface. About 71 tons is said to have 
been obtained in this way. 

The main vein appears to continue for about a mile 
north, where it is 20 ft. wide, and has there also been 
worked for tantalum. 

Since Mr. Maitland reported on this field other tantalum- 
bearing dykes have been opened up in the vicinity, and 
ore is still being obtained from shallow surface soils, as 
well as from true alluvial deposits in the many small 
valleys. 

(To be continued). 



THE OSMOTIC PRESSURE OF 

CONCENTRATED SOLUTIONS, AND THE LAWS 

OF THE PERFECT SOLUTION.* 

By GILBERT NEWTON LEWIS. 

(Continued from p. 42). 

The Law of Ideal Solutions. 
What we shall call a perfect or ideal solution is some- 
what a matter of choice. We might define as an ideal 
solution one which obeys the law of van 't Hoff, or the 
modified form of this law proposed by Morse and Frazer, 
or the law of Raoult, or the law of Henry. These laws 
are essentially identical for the infinitely dilute solution, 
but for a solution of finite concentration we are at liberty 
to choose one but not all of these laws to define the ideal 
solution. No one of them is true for every solution at 
every concentration, and we must therefore choose that 
one which holds most nearly for the greatest number of 
substances over the widest limits of concentration. 

I shall attempt to show that the most fundamental law 
of solutions and the one by which the perfect solution is 
best defined is the following modification of the law of 
Raoult. At constant pressure and temperature the activity 
of the solvent in a perfect solution is proportional to its 
niol. fraction. (For a definition of the term activity see 
Lewis, " Outlines of a New System of Thermodynamic 



♦ Ffom the Journal of the American Chemical Society, xxx., No. 5. 



Chemistry," Proc. Am. Acad., 1907, xliii., 259 ; and Zeit. 
Phys. Chem., 1907, Ixi., 129; C, A., igoS,6ii). That is — 

I = ^oN 4 ; 

where | is the activity of the solvent in the solution, Jo the 
activity of the pure solvent, and N, the mol. fraction, is 
the number of mols. of solvent in one mol. altogether of 
solvent and solute. Since, however, the conception of 
activity is new, and since if the vapour of the solvent 
obeys the gas law the activity is proportional to the vapour 
pressure, we may with sufficient exactness for our present 
purposes, substitute the vapour pressure of the solvent for 
its activity and write — 

p = po^ 5 ; 

that is, in a perfect solution the vapour pressure of the 
solvent is proportional to its mol. fraction. (The point 
of view here adopted is practically identical with that 
which for several years has been advocated by J. J. van 
Laar in numerous publications). Thus in a solution con- 
taining o*i mol. solute to 0-9 mol. solvent, N^o-g and 
the vapour pressure of the solvent should be nine-tenths 
of its vapour pressure in the pure state, or if the solution 
contains o'25 mol. solute to 0*75 mol. solvent, p should be 
075 po. This is simply a statement of Raoult's law in its 
simplest form. 

(Note. — It is important to note that Equation 4 leads us 
immediately to a simple equation for the activity or the 
vapour pressure of the solute. In the paper previously 
referred to I have proved the following exact equation for 
the change in the activity of each component of a binary 
mixture with change of composition, namely — 

Nirf/«{i-|-Nd/H| = o, 

where Ni is the mol. fraction and |i the activity of one 
constituent which we will call the solute, and N and | are 
the corresponding terms for the other constituent which 
we will call the solvent. Now, when Equation 4 is true, 
dln^ = dlnN. Substituting in the above equation and 
noting that by definition Ni=«i -N we find — 

Nidln^i -i-dN =0, or 

dln^i = dlnNi, or 

Ji=-KNi, 

where K is a constant. We see, therefore, that in a 
perfect solution it is also true that the activity of the solute 
is proportional to its mol. fraction. If we substitute pi, 
the vapour pressure of the solute, for Ji, pi = KNi, which 
is, in a slightly modified form, the law of Henry. In other 
words, if both vapours obey the gas law, the law of Henry 
may be derived thermodynamically from the law of Raoult 
and must hold if that law does). 

There are no cases in which the law of van 't Hoff or 
the modified form of this law proposed by Morse and 
Frazer have been shown to hold at concentrations higher 
than normal. (In a normal solution in water the mol. 
fraction of the solute is about 0-02). 

Indeed, at very high concentrations van 't Hoff^s law 
cannot hold, for the osmotic pressure of a solution ap- 
proaches infinity as the percentage of solvent approaches 
zero, while the osmotic pressure calculated from the van 't 
Hoff equation never exceeds a few hundred atmospheres 
even when we approach the condition of pure solute. On 
the other hand, it will be shown presently that the law 
proposed by Morse and Frazer ordinarily gives, at higher 
concentrations, osmotic pressures far higher than those 
which actually exist. But often the law of Raoult (and 
the modified law of Henry) has been shown to hold at all 
concentrations from o per cent to 100 per cent 0/ solute, and 
while in many other cases this law does not hold, the 
greatest deviations are always found in those cases in 
which we have reason to believe that the solvent and the 
solute form complex compounds either with themselves or 
with each other. 

Many illustrations might be given to show the remark- 



Chemical News,) 
Jan. 29, 1909 t 



Agrosterol. 



53 



able scope of Raoult's law. I will choose a binary mix- 
ture which has been studied more carefully over a wide 
range of concentration than any other, namely, benzene 
and ethylene chloride. The vapour pressures are taken 
from the excellent paper of Zawidski [Zeit. Phys. Chem., 
1900, XXXV., 129). We will call benzene the solvent and 
ethylene chloride the solute. In Table III., in which the 
data marked by Zawieski as questionable are omitted, the 
first column gives the number of grms. of solute to i grm. 
of solvent, the second gives the partial vapour pressure of 
the solvent at 50°, and the third gives the molecular weight 
of ethylene chloride calculated from the vapour pressures 
by Raoult's law. The calculated molecular weights are 
constant, even up to the highest concentration, where the 
solute constitutes over 90 per cent of the solution. The 
average of these calculated molecular weights isgg-i, while 
the actual molecular weight of ethylene chloride is 99*0. 
(We have therefore every ground for believing that also in 
the pure state ethylene chloride exists in the form of 
simple molecules). 

Table III. 

Grms. C-2H4C12 M.W. 

to 1 grm. CgHg. P of CfiHo. C2H4C1-2. 

CO 268'o — 



0-525 
0-904 
1-39 
2-43 
3-89 
I4'54 



156-0 

127-8 

92-4 

65-9 
21-8 



99'4 
98-2 
98-7 

99*3 

99-0 

loo-o 



Average 99-1 

Theoretical . . . . 99-0 

If then we define a per'ect solution as one which obeys 
Raoult's law,* it is interesting to find what the law is con- 
necting osmotic pressure and concentration in a perfect 
solution. This law, which is less simple than either the 
law of van 't Hoff or that of Morse and Frazer, may be 
derived directly from Equations 3 and 5, and is — 



n -—aW 
2 



Vo 



6, 



n- - an"-= - ^7/»(i-N) .... 7, 

2 Vo 

where Vo is the molecular volume and a the compressibility 
of the solvent. 

(To be continued). 



AN APPARATUS FOR SIMULTANEOUSLY 

EXTRACTING A SOLID AND FILTERING THE 

SOLUTION SO OBTAINED. 

By FREDERICK RECORD, B.Sc. 

In the Chemical News of June 12, 1908 (vol. xcvii., 
p. 280) there appeared a drawing and description of a form 
of apparatus for the above purpose, which consisted wholly 
of glass, and which had the disadvantage of requiring con- 
siderable skill in its construction. The accompanying 
section shows a modification of the apparatus which can 
be made much more readily. The inner tube, a, is con- 
tracted at its lower extremity, and has a pair of diametri- 
cally opposite holes, c, in its walls; it is held in position 
inside the outer tube, b, by means of a cork, h ; e is a 
filter disc which is covered with a layer of filter-paper and 

* Strictly speaking, we define a perfect solution as one which obeys 
Equation 4 rather than Equation 5, but the more precise method 
which employs the activity instead of the vapour pressure leads to 
exactly the same equation for the osmostic pressure as we shall 
derive here. 




of asbestos, f ; g is the substance to be extracted. The 
flask containing the solvent is attached to the lower end of 
B, while a reflux condenser is connected to the upper end 
of A. 

The Technical College, Derby. 



THE PRESENCE OF A CHOLESTEROL 

SUBSTANCE IN SOILS: AGROSTEROL.* 

By OSWALD SCHREINER and EDMUND C. SHOREY. 

In the attempts which have been made to isolate definite 
organic compounds from soils it has been found that in 
most cases treatment of the soil with alcohol even at 
boiling temperature does not give a solution of soil organic 
matter from which definite results could be obtained. 

However, with some soils, characterised usually by a 
high content of organic matter, this treatment has led to the 
isolation and identification of definite organic compounds. 

The details of the method and the properties of one of 
the compounds obtained are the subject of this paper. 

The soil from which this compound was obtained was 
the Marshall clay from North Dakota, a black soil con- 
taining IO-6 per cent organic matter and 0-51 per cent 
nitrogen. 

When this soil was treated with boihng 95 per cent 
alcohol there was obtained a greenish brown coloured 
extract, from which, on cooling, a yellowish microcrystalline 
precipitate separated. On treating the soil with successive 
portions of boiling alcohol, the extracts, combined and 



* Presented at the New Haven Meeting, June, 1908, of the American 
Chemical Society, by permission of the Secretary of Agriculture. 
From the Journal oj the American Chemical Society, xxxi., No, i. 



54 



A tomic Weights of Nitrogen and Silver. 



(Chemical News, 
I Jan. 29, 1909 



concentrated to smaller volume and allowed to cool, 
yielded this precipitate in considerable quantity, 250 — 300 
parts per million of soil. This precipitate contained both 
mineral and organic matter, and is at present the subject 
of further investigation. The mineral matter is alumina 
for the most part, and the organic portion is a mixture, 
some of the so-called waxy acids being present. 

The filtrate from this precipitate was a dark greenish 
brown solution which on evaporation of the alcohol became 
a thick resinous mass. On treating this residue with cold 
ether nearly all of the colouring matter went into solution, 
leaving a small quantity of a yellowish wax-like substance, 
the nature of which is yet unknown. 

The coloured ether solution on evaporation of the ether 
left again a thick viscous residue. Treatment of this with 
successive small quantities of cold absolute alcohol removed 
the colouring matter, leaving a nearly white residue. This 
residue was readily soluble in ether and crystallised from 
such solution in needles, usually arranged in radiating 
clusters. If, however, this body was dissolved in hot 
80 per cent alcohol, in which it is quite easily soluble, it 
crystallised in flat plates very similar in appearance to 
those of phytosterol. 

The compound so obtained melts at 237° (uncorrected), 
and the melting-point remains unchanged after re-crystal- 
lisation. It is readily soluble in ether or chloroform, 
little soluble in cold alcohol, but readily so in hot, and 
almost insoluble in hot water. It is unchanged by treatment 
with alcoholic potash. When crystallised from 80 per cent 
alcohol it contains water of crystallisation which is lost 
at 100°. 

The appearance and properties of this substance sug- 
gested a member of the cholesterol group, and it was 
found to respond readily to Liebermann's " cholesterol 
reaction," but gave no reaction with other colour tests 
for members of this group. Liebermann's reaction is 
characterised by the violet colour produced when a drop 
of strong sulphuric acid is added to a solution of the sub- 
stance in acetic anhydride. This test is best performed by 
dissolving a very small quantity of the substance in a few 
drops of chloroform, adding about i cc. of acetic anhydride, 
and then one drop of concentrated sulphuric acid. With 
the compound from the soil the colour produced by this 
treatment is intense, appears immediately, and a good 
reaction is obtained with a very minute quantity. 
Cholesterol and a number of isomeric substances which 
have been described are usually represented by the formula 
C26H44O-I-H2O. Very little, however, is known of their 
constitution beyond their alcoholic nature, and even 
the elementary composition is doubtful, the formula 
C27H44O t H2O being given by some investigators. 

The composition of the compound obtained from the soil 
was found to agree very closely with the formula C26H44O. 
The analysis was made with o'i5 grm. dried at 100°. 
Calculated for C26H44O : C, 838; H, ii-8. Found: 
C, 83-6; H, 11-5. 

The melting-points of most of the described cholesterol 
substances are much lower than that of the body obtained 
from soil. Cholesterol found in animal fats melts at 
145 — 6°, phytosterol found in vegetable fats and waxes 
melts at 132 — 3°, isocholesterol found in some animal fats 
melts at 137 — 8°, paracholesterol found in etiolated yellow 
lupines melts at 134 — 134'5", sitosterol found in plant fats 
melts at i37'5, paraphytosterol found in the seed coat of 
Phaseolus vulgaris melts at i48'5o^, parasitosterol found 
in the embryo of wheat melts at 127-5°, homocholesterol 
found in Dalmatian insect powder {Chrysanthemum 
cinerariaefolium) melts at 183"^, and ergosterol found in 
ergot melts at 154°. However, anthesterol, a closely 
related alcohol found in Anthemisnobilis, melts at 221 — 3° 
and arnesterol found in Arnica montana melts at 249 — 50°. 

The cholesterol substance obtained from the soil does 
not correspond in melting-point with any substance of this 
group so far described. For this compound, isolated from 
a soil, having the chemical properties and general appear- 
ance of substances of the cholesterol group, but differing in 



melting-point from any of the members of this group so 
far described, the generic name agrosterol is suggested 
in harmony with the nomenclature of this group. 

With regard to the origin of this compound in the soil at 
least two possibilities present themselves : — It will be seen 
that several members of the cholesterol group are so far as 
known found only in single species of plants. It may be 
that agrosterol is characteristic of some plant grown on 
this soil, and that on the decay of plants of this species it 
has survived the action of enzymes, fungi, and bacteria, 
and remained in the soil as an unchanged plant residue. 
Since, however, the presence of a substance of this group 
is shown by Liebermann's reaction above mentioned in 
several soils from widely separated localities with different 
native vegetation and cropping, it would seem that this 
suggestion has not much weight. To make this con- 
clusive it would be necessary to show that the substances 
from different soils giving Liebermann's reaction are really 
identical, since the reaction is only a class reaction and 
not specific for agrosterol or any other member of the 
cholesterol group. 

On the other hand, it is within the range of possibility 
that agrosterol may be formed from some other substance 
through the agency of micro-organisms or chemical 
oxidation. The fact that Lifschiitz has shown that a 
cholesterol substance can be formed by the oxidation of 
oleic acid emphasises this possibility (Zeit. Physiol. Chem., 
1908, Iv., i). The fact that paracholesterol mentioned 
above is found in slime moulds further supports the sug- 
gestion that agrosterol may be formed by micro-organisms. 
Agrosterol is very little soluble in water, and saturated 
solutions of it had no effect on wheat seedlings. 



FURTHER INVESTIGATION OF THE 
ATOMIC WEIGHTS OF NITROGEN AND SILVER.* 

By THEODORE WILLIAM RICHARDS, PAUL KOTHNER, 
and ERICH TIEDE. 

The Analysis of Ammonium Chloride. 

The subject of atomic weights has acquired new interest 
recently, because of the striking demonstration by Landolt 
that the law of the conservation of weight holds true to a 
great degree of precision in common chemical reactions 
(Landolt, Sifzunber. Kgl. Preuss. Akad., 1908, xv. — xvi., 
354). The fact that the sum of the reacting weights 
remains perfectly constant, within the limit of error of the 
most exact experimentation, strengthens the conviction 
that each of these reacting weights possesses fundamental 
significance. Evidently no error is committed in calculating 
one atomic weight by subtracting another from the mole- 
cular weight of a substance containing two elements, and 
the whole structure of the table of atomic weights is seen 
to rest on a satisfactory basis. 

These assurances are timely in view of the extraordinary 
discoveries concerning radio-activity in recent years. Not 
a few radical thinkers have supposed that these discoveries 
lessen the importance of exact atomic weight determina- 
tions because of the doubt cast on the permanence of the 
supposed atom, but Landolt's admirable work assures us 
that under ordinary circumstances the chemical combining 
proportions are wonderfully permanent, and therefore as 
full of meaning as they have ever been supposed to be. 
The new discoveries concerning radio-activity extend the 
bounds of knowledge, but in no wise lessen the significance 
of that which went before. 

Nitrogen and silver are two of the elements whose atomic 
weights are at present especially in the focus of attention. 
Each element is important in many ways because of its 
frequent occurrence, and each is particularly important in 
the present connection because of the extent to which the 
value of its atomic weight is involved with the values of 

* Journal of the American Chemical Society, xxxi., No. i. 



Chemical News, 
Jan. 29, igog 



Atomic Weights of Nitrogen and Silver. 



55 



other atomic weights. Therefore the value of these two 
should be settled precisely as soon as possible. 

During the past one hundred years as many as ninety 
different investigations, carried out by more than thirty 
chemists, have been concerned with the atomic weight of 
nitrogen, and many of these have also had to do with the 
atomic weight of silver. Most of this work is unsatisfactory 
in the light of modern knowledge. The compounds of 
nitrogen and oxygen on the one hand, and silver and 
oxygen on the other, are not stable enough to be subjected 
to exact analysis suitable for this purpose ; therefore by the 
chemists both elements have to be evaluated with the help 
of other compounds, involving other elements, This in- 
troduces difficulties upon which many have stumbled. 

The physical method of determining molecular weight 
through gas densities avoids this complication, but, on the 
other hand, introduces troubles of its own, the chief of 
which is the difficulty of extrapolating to the ideal con- 
dition. It is true that in the case of nitrogen, as Lord 
Rayleigh has pointed out, the method is especially applicable 
— but it must of course be supported by chemical evidence 
to be wholly satisfactory. 

Two methods of determining the atomic weight of 
nitrogen in the chemical fashion have been used by most 
chemists, namely, the analyses of nitrates and the analyses 
of ammonium salts. In each of these sets of compounds 
nitrogen exists in combination with two other elements, 
but in the case of the nitrates one of these other elements 
is the standard of the atomic weights itself, namely, 
oxygen, and in the case of the ammonium salts the two 
other elements both have many other accurately deter- 
mined quantitative relations. The study of silver nitrate 
was undertaken by Stas, and more recently by Richards 
and Forbes in the chemical laboratory of Harvard College. 
These results were not very different, and the latter pointed 
strongly to a value for the atomic weight of nitrogen equal 
to i4'oo8, if silver is taken as io7'88 ; but if silver is taken 
as 10793, with Stas, nitrogen will be almost 14-04. It 
seemed highly desirable therefore to obtain an entirely 
different set of evidence upon this point through the study 
of the ammonium halides in their relation to silver — a study 
which likewise led Stas to a higher value — and the present 
paper treats the first of a series of investigations upon this 
subject, concerning the analysis of ammonium chloride. 

The history of the analysis of this compound is quickly 
told. Stas found as an outcome of a number of experi- 
ments that 49'597 grms. of ammonium chloride required 
loo'oooo grms. of silver for precipitation. These analyses, 
careful as they were, are open to doubt from two causes, one 
of which has been pointed out by Alexander Scott in an 
interesting paper upon this subject (A. Scott, yoiirn Chem. 
Soc, 1901, Ixx., 147). Scott calls attention to the fact 
that Stas was never able to prepare ammonium salts wholly 
free from colour — an evidence that he had never succeeded 
wholly in eliminating the carbon compounds always present 
in chemical substances. Scott himself, by means of more 
drastic treatment, probably succeeded better in this respect. 

Unfortunately, both Stas's extensive work and Scott's 
two analyses of ammonium chloride were evidently in- 
adequate as regards taking account of the solubility of 
silver chloride, so that these determinations throw but little 
light upon the question. This deficienc}', which occurs in 
most other early work, is the second cause of doubt con- 
cerning Stas's work with chloride. 

It is clear, therefore, that the whole subject needs a 
thorough investigation and revision in the light of modern 
knowledge concerning both the purity of materials and 
precision in analysis. 

Preparation of Material. — The most important new 
problem concerning the analysis of the ammonium chloride 
is the preparation of the material to be used in the analyses, 
for of course the purity and constant composition of this salt 
must be beyond suspicion. The impurities most commonly 
to be found in ammonium salts include various compounds 
of carbon, and these are usually the most difficult to 
eliminate. Non volatile substances, such as salts of the 



alkali metals, are of no great consequence. They may 
easily be eliminated by converting the ammonium salt into 
ammonia gas and collecting the gas in pure acid. 

Stas sought to eliminate the amines by two oxidising 
processes, one, the treatment of ammonium chloride by 
nitric acid, and the other, the treatment of ammonium 
sulphate at high temperature with concentrated sulphuric 
and nitric acids. Scott used the latter of these methods. 
These methods undoubtedly decompose most of the 
amines, but no one has proved that all are eliminated in 
either of these ways. In view of this doubt it was deemed 
advisable to use quite another method for the purpose, and 
nothing seemed more suitable than an application of one 
of the devices of Kjeldahl for eliminating carbon from am- 
monium compounds. To every 100 grms. of ammonium 
sulphate and 75 grms. of concentrated sulphuric acid, con- 
tained in a beaker of Jena glass and heated to the point 
where the sulphuric acid began to volatilise, were added in 
very small portions a few grms. of finely powdered potas- 
sium permanganate. The solution was then heated for 
many hours to a high temperature until the evolution of 
carbonic acid and oxygen had ceased and the solutiom 
had become wholly colourless — an evidence that the 
oxidation had reached its limit. After cooling, the cakes 
of acid ammonium sulphate were dissolved in pure water, 
and the ammonia was set free by means of freshly pre- 
pared milk of lime. The lime for this purpose was made 
by the ignition of pure calcium carbonate in an electric 
oven for many hours, and could have introduced no im- 
purity. The simplest method of collecting the gas was 
found to be the placing of a quartz or platinum dish, con- 
taining the purest hydrochloric acid, over the mixture of 
ammonium sulphate and milk of lime in a vacuum 
desiccator or ground glass bell-jar. The ammonia quickly 
transfers itself from the mixture to the acid, and without 
trouble or danger from spattering the preparation is easily 
made. This simple method proved itself very much more 
satisfactory than the attempt to distil the ammonia with 
steam either from an outside source or by heating the 
semi-solid mixture of calcium sulphate and ammonium 
hydroxides. The salt prepared in this way is always 
beautifully white in appearance. The sample prepared in 
platinum showed no trace of contamination, but, even sup- 
posing a small amount of platinum had been dissolved (see 
Note), it would have been eliminated by the subsequent 
sublimation described later. This sample of ammonium 
chloride is given the designation A in the following pages. 

Note. — Dr. F. W. Hinrichsen found difficulty from this 
source, but it is possible that the air was less fully 
exhausted from his apparatus. In the absence of air the 
platinum is not attacked (Zeit. Anorg. Chem., 1908, 
Iviii., 59). 

No single method of preparation is adequate for a case 
of this sort, as has often been pointed out. Some entirely 
different method must be adopted for preparing another 
sample, in order to be certain that constant impurity has 
not found its way into the first in spite of all precautions. 
Stas, realising this, prepared ammonia also by reducing 
potassium nitrate. He thought that in this way he must 
obtain a salt free from organic compounds. In the first 
place he made the nitrite out of saltpetre and lead, and 
then reduced it by means of zinc and potash. It is by no 
means certain that these materials were all free from 
carbon, and if they were not, the doubt concerning the 
existence of amines synthesised during the process of 
reduction still remains. Although thus Stas's execution of 
his idea was not without reproach, the idea was a good 
one, and we sought to carry it out in another way, 
using substances really free from carbon, and bringing into 
play new physico-chemical knowledge. Vortmann (Bir., 
1890, xxiii., 2798) made at the beginning of the last decade 
an observation that under proper experimental conditions 
it is possible to reduce nitric acid quantitatively to ammonia 
by means of the galvanic current, provided only that copper 
is present in the solution and forms the material ol the 
electrodes. In those days the advantage to be obtained 



56 



A tomic Weights of Nitrogen and Silver. 



I Chemical News, 
I Jan. 29, 1909 



by stirring the solution during electrolysis was not fully 
realised, but very recently Ingham {jfourn. Am. Chem. 
Soc, 1904, xxvi., 1251) has shown that this process, like 
all other electrolytic processes, is much hastened in this 
way. The subject has also been investigated in an 
empirical fashion by Patten (jfourn. Am. Electrochem. 
Soc, 1907, xii., 325). The experience of this last investi- 
gator was not available to us at the time of our work, 
having not yet been published ; accordingly, as the process 
promised well for the present purpose. Dr. F. W. 
Hinrichsen [Zeit. Anorg, Chem., 1908, Iviii., 59) kindly 
tested the process with the idea of finding out its efficiency 
and the best conditions for obtaining high purity of product 
and maximum yield. This work has already been described 
in another place. It is enough to say that he found it con- 
venient to use a cathode of copper netting in a cylinder 
about 10 centimetres in diameter and 10 centimetres high, 
and an anode of platinum foil, with a current of not over 
3 amperes, if the solution was tranquil. It was found 
advantageous to use a large platinum dish coated inside 
with copper for the cathode when working with a rotating 
anode. Equal weights of copper sulphate and re-distilled nitric 
acid were mixed with about ten times their combined weight 
of water, and, as the nitric acid was exhausted by reduction 
and the copper by deposition, more was added. In order 
to stir the solution he used also the device of Frary [Zeit. 
Elektrochem., 1907, xiii., 308), by which the solution was 
whirled by mean« of the electro-magnetic effect of a sur- 
rounding solenoid. Considerable current is needed in 
order to cause such agitation in the liquid, but the method 
has the advantage for the present purpose of excluding the 
danger of dust which comes from any sort of mechanical 
stirring run by an outside motor. Obviously the pure nitric 
acid for this purpose, having been twice distilled, was pre- 
pared with great care, and diluted with the purest water. The 
copper sulphate used was also purified by several re-crystal- 
lisations. The solution was heated in order to avoid the 
formation of hydroxylamine, for Tafel has shown that 
under these circumstances the electrolyte contains less of 
this substance. (Tafel, Zeit. Anorg. Chem., 1902, xxxi., 
282 ; Patten, loc. cit., apparently never worked above 30°, 
and accordingly was not able to verify this statement). 
Even if some had been formed, however, it would have 
inevitably been decomposed in the later operations. From 
the ammonium sulphate made in this way pure ammonium 
chloride was made in the manner already described. This 
sample was called B. 

For a few analyses a cruder preparation was used, made 
according to Stas's first method by repeated treatment of 
ammonium chloride with nitric acid, at a boiling tempera- 
ture, and five re-crystallisations. For freeing the crystals 
from mother-Kquor the new centrifugal apparatus of 
Richards and Staehler was employed. A fourth prepara- 
tion, prepared by a student at Harvard by the same 
process, was also used for two analyses. These two similar 
preparations, possibly less pure than the others because of 
the method used in their preparation, were called C 
and D. 

The ammonium chloride thus prepared was — at least, 
as regards samples A and B — very pure with the exception 
of the presence of an excess of hydrochloric acid and water. 
Most of the preparations showed a feebly acid reaction 
after evaporation to dryness. They were each re-crystal- 
lised several times out of water containing a little ammonia 
prepared by the same process. These crystallisations were 
effected in quartz or platinum dishes, and the heating was 
conducted by electricity in order to avoid contamination 
from illuminating gas. Needless to say, dust was ex- 
cluded as carefully as possible. The mother-liquor was 
separated as usual by means of the platinum centrifuge of 
great power. The preparation thus obtained was snow- 
white and possessed a slight smell of ammonia. It was 
dried in a vacuum desiccator and kept over potash in 
quartz or platinum dishes. The final preparation of this 
material for analysis was by sublimation. Each sample 
was sublimed twice immediately before analysis, collecting 



it the second time in the vessel in which it was to be 
weighed. This operation will be discussed in a subsequent 
chapter. 

All the other substances, water, hydrochloric, nitric, and 
sulphuric acids, silver, calcium carbonate, &c., were pre- 
pared by essentially the methods which have been used for 
a number of years in Harvard University and are described 
in detail in the various papers from that institution, 
especially in Publication 69 of the Carnegie Institution of 
Washington. There is no need of reviewing these well- 
known methods. It goes without saying that great care 
was taken to avoid the use of utensils whose solubility 
could contaminate the products or influence the reactions. 
Whenever possible quartz dishes were used with acid 
liquids, and platinum ones with alkalis; and where glass 
was unavoidable the best Jena glass was employed. 
Electric heating was used almost universally in order to 
avoid objectionable products of combustion. For vacuum 
work the convenient, almost automatic mercury pump of 
Ubbelohde-Stock was used with profit, and apparatus was 
constructed without rubber connections, being fused to- 
gether wherever it was possible. For the necessary glass 
joints a paraffin lubricant of vanishingly small vapour 
tension was kindly given us by Professor Brauner, of 
Prague. Many bell-jars served to protect the substances 
from dust and objectionable gases. The laboratory was a 
room in the First Chemical Institution of Berlin especially 
dedicated to the purpose through the kindness of Geheimrat 
Emil Fischer, and this room was kept as free as possible 
from soluble gases of all kinds. The quantitative work 
was carried out in an especial room used by the experi- 
menter alone, and another special room served for the 
balance. The dark-room used for the preparations was 
not interfered with by any other investigation during the 
time while this was in progress. 

All these favourable conditions contributed greatly to 
the success of the undertaking. Without advantages of 
this sort much time and experimental energy may be 
wasted, because one's efforts are rendered vain by the 
inevitable introduction of impurities from the atmosphere. 
Not only in this way, but also by providing plentiful ap- 
paratus of rare and expensive kinds. Professor Fischer 
did much to further the work, and we take great pleasure 
in recording our grateful thanks. To Dr. A. Staehler we 
are also greatly indebted for his kindness in attending to 
the arrangement of the laboratory, and for help in many 
details. 

(To be continued). 



Optical Investigation of the Copper Complexes in 
Ammonia and Pyridine Solution. — A. Hantzsch and 
P. W. Robertson. — All cupric compounds are optically 
identical in all aqueous and alcoholic ammonia solutions, 
and contain only the complex Cu(NH3)4 as chromophor. 
All copper solutions with the complex Cu(NH3)4 are 
unaffected by changes of temperature, solvent, &c. 
Apparent alterations are to be ascribed to changes in the 
complex, e.g., to the formation of the complex 

CuLiT ^". All copper salts are optically identical in 

aqueous pyridine ; the copper pyridine complex is less 
stable than copper tetrammine, and has the composition 

Cu^^ . Copper acetate solutions contain another com- 

\jn.2 

plex of formula Cu,^? > in pure and alcoholic pyridine 

solution. Copper acetate solutions in water, methyl, 
ethyl, and amyl alcohol are optically different, and contain 
different complexes. From the fact that water and 
alcohol on entering the complex alter its colour, it follows 
that copper tetrammine is dissolved in all solutions as such 

and not in the form of a complicated complex of formula 

■p 
Cu,»?TT \ , for instance. Thus copper only forms com- 

(^•"3/4 
plexes of the type CUR4, and its co-ordination number is 4. 

— Berichte, xli., No. 17. 



Chemical News, 
Jan. 29, 1909 



John Dalton and the Atomic Theory. 



PROCEEDINGS OF SOCIETIES. 

ROYAL SOCIETY OF NEW SOUTH WALES. 
General Monthly Meeting, December 2nd, 1908. 

W. M. Hamlett, F.LC, F.C.S., President, in the Chair. 

The following papers were read : — 

" The Discontinuity of Potential at the Surface of 
Glowing Carbon." By J. A. Pollock, A. B. B. Ranclaud, 
and E. P. Norman. 

In a circuit with one heated electrode in air at ordinary 
pressure, the projection of ions from the hot surface neces- 
sitates the establishment of a potential difference between 
the electrodes if the current in the circuit is to be zero. 
This potential difference under certain circumstances may 
be taken as a measure of the surface discontinuity, and 
values have been obtained in the case of glowing carbon at 
various temperatures. 

Abstract of lecture on " yohn Dalton and One Hundred 
Years of the Atomic Theory." (Illustrated by diagrams 
and models). By F. B. Guthrie, F.I.C, F.C.S. 
Delivered November 19th, 1908. 

The lecturer after shortly reviewing Dalton's life dis- 
cussed the position of the Atomic Theory in the develop- 
ment of the science. The history of chemistry since 
Dalton has been the development, extension, and modi- 
fication of the theory. Previous conceptions of the atomic 
structure of the Greek were then discussed, notably those 
which we owe to the Greeks and Lucretius, and it was 
shown that, though it is customary to regard Dalton's 
theory as a development of the Greek, Dalton's conception 
of the atoms differed fundamentally from theirs. As first 
enunciated the law explained satisfactorily certain pheno- 
mena then for the first time noticed, but was not free from 
objection owing to. confusion arising between the con- 
ceptions of atoms and of compound atoms or molecules, and 
owing also to an arbitrary assumption on Dalton's part as to 
the proportions in which the elements combine, as well as 
to the difficulty in correctly determining the atomic weights. 
These difficulties were got over largely by the acceptance 
of the important law known as Avogadro's law, and the dis- 
covery of relationships between the atomic weights and 
the physical properties of the elements which enabled the 
atomic weights to be verified with considerable accuracy. It 
was soon found that a very profound and highly significant 
relationship existed between the atomic weights of the 
elements and their general properties. This was first 
observed by Newlands the English chemist, but developed 
later by Mendeleeff into the Periodic Law. This highly 
important generalisation, based as it is on the atomic 
theory, is one of the most important achievements of this 
theory. In other directions the atomic theory has 
developed in ways equally important and unforeseen. By 
its means chemists have been able to learn something of 
the constitution of the most complex forms of matter. The 
doctrine of valency introduced by Frankland is a direct 
corollary of the atomic theory. The modern development 
of the theory of valency has led us to the most ingenious 
and beautiful explanations of the internal groupings of the 
atoms in chemical substances, and has been especially 
prolific in the discovery and synthesis of new substances in 
the benzene group, notably the dyes and other remarkable 
substances known as the coal-tar derivatives. It has also 
served to explain the remarkable optical behaviour of 
substances otherwise identical. At the present time we 
are undergoing a change in our conception of the nature of 
the atom. Research into the electrolysis of solutions, the 
ionisation of gases, and radio-activity have familiarised 
us with the idea that the atom is not to be regarded as 
indivisible, but as composed of yet smaller particles — 
electrons — the escape of which from the atom give rise to 
the phenomena of radio-activity. All these manifestations 



57_ 

can only be satisfactorily explained on the assumption that 
what we observe is the disintegration of the atom, and that 
the energy is derived from the internal energy, a view which 
brings us to the new conception that the atomic weight is 
a function of the internal energy of the atom. We are also 
familiarising ourselves with the idea that it is quite possible 
that the elements are mutually convertible. We have 
become familiar with the notion that the so-called radium 
emanation passes over into helium, and in recent papers 
by Ramsay and Cameron, these authors consider that the 
effect of the action of emanation upon water and copper 
sulphate is to produce the gases neon and perhaps argon, 
whilst in the case of the action on copper sulphate the 
copper would appear to be degraded into lithium and sodium. 
In the case of the formation of neon the authors consider 
it to be indisputably proved. In the other cases they are 
less certain. These modifications must not be regarded as 
upsetting or supplanting the atomic theory, but merely 
as rendering necessary some modification of our present 
conceptions of the atom ; notably its invariability and 
indivisibility. 



NOTICES OF BOOKS. 



Sketches from the Life of Sir Edward Frankland, K.C.B. 

Edited and Concluded by his two Daughters M. N. W. 

and S. J. C. London : Spottiswoode and Co., Ltd. 
The student of physical science often feels the want of 
some general reading in the subjects which specially 
interest him, quite apart from his academical work and 
yet in some way bearing upon it. This want cannot be 
better supplied than by biographical literature, and the 
peculiar charm of a good autobiography is very marked in 
this book. The story of Sir Edward Frankland's life is 
told almost entirely in his own words ; the awakening of 
his interest in experimental science and his subsequent 
devotion to the subject are described in vivid language, 
and chapters on the researches which he brought to a 
successful conclusion, and by which he gained so 
much renown, give a summary of his activity in the 
scientific world. These chapters are excellent reading for 
students of organic chemistry, who will always find it 
worth while to make themselves acquainted with the 
original papers of investigators, especially when their work 
is that of a genuine pioneer. Special attention must be 
called to the discussion of Frankland's work on the deter- 
mining factors of the luminosity of flames, which is far too 
little known. Delightful chapters on the author's ex- 
periences on his travels show him to have been, as indeed 
his whole career pointed out, a man of keen appreciations, 
lively interests, and wide culture. Though parts of the 
autobiography may be too technical for the general public, 
many portions of it will interest every reader, who will 
gain from it an acquaintance with the charming personality 
of a man of genius, whose letters show quick powers of 
observation and deep insight. 



Recent Advances in Organic Chemistry. By A. W. 
Stewart, D.Sc. London, New York, Bombay, and 
Calcirtta : Longmans, Green, and Co. 1908. 
This book can only be described as simply invaluable for 
students of organic chemistry. To many the study of 
organic chemistry means nothing more than the acquire- 
ment by rote of a greater or smaller number of facts, the 
meanings and correlation of which are practically passed 
over altogether, and the extinction of this wholly false 
view is one of the aims of the author, while the constructive 
object is to stimulate the reader's own critical and selective 
powers to follow the most modern advances in methods of 
thought and argument. Exceedingly clear accounts are 
given of methods of synthesising newly discovered com- 



58 



Notices of Books, 



Chemical News 

Jan. 29, igog 



pounds among the polyketides, polymethylenes, poly- 
peptides, alkaloids, &c., and for these alone the book has 
a special value as providing a key to the bewildering 
accumulation of details which is to be found in articles 
appearing in periodicals dealing with organic chemistry. 
But the book is more than an account of the work which 
has already been done ; it points out the methods by 
which the almost countless facts which have been ascer- 
tained by research will be brought into relation with one 
another, and how order will be made out of them. Al- 
though the connection between physical properties and 
chemical constitution is only lightly touched upon, the 
author's belief that we are standing on the brink of a 
revolution in our views upon the fundamental questions of 
organic chemistry is discussed in an interesting concluding 
chapter. An introduction calling attention to the special 
features of the work has been written by Prof. Collie. 



Chapters on Papermaking. Vol. V. By Clayton Beadle- 

London : Crosby Lockwood and Sons. 1908. 
The fifth volume of this text-book of paper making deals 
with the theory and practice of beating, and is mainly 
occupied with the description of tests carried out by the 
author with different types of machines and different 
classes of materials. The book thus provides a good deal 
of numerical information upon which a thorough scientific 
knowledge of the subject of beating may be based ; much 
of it has not been published before. Every effort has been 
made to obtain reliable and comparable data, and the tests 
carried out relate to the maximum power consumption of 
different types of machines, the relative merits of stone and 
metal beater bars, power consumed in grinding wood pulp 
in comparison with that required for beating, &c. A con- 
spicuous merit of the book is the clearness with which it 
treats in a popular style of a branch of paper-making which 
has hitherto been somewhat neglected, and thus it lays the 
foundation for a fuller and more comprehensive study of 
the theory and practice of beating. 



Leather, Technical and Practical. London : The Leather 

Trades Publishing Company. 
This new monthly journal for all engaged in the leather 
industries will undoubtedly meet a want, and if the first 
number may be accepted as an average specimen of what 
it will provide, it will very soon make a place for itself in 
the scientific and technical world. The journal opens 
with an article upon " Some Unsolved Problems in Leather 
Chemistry," by Prof. Procter, in which an interesting 
account is given of the directions in which our knowledge 
of the chemistry of leather manufacture will probably 
develop in the immediate future. Other original articles, 
which are to be a conspicuous feature of the new paper, 
include one on " The Quality of Sole Leather " and on 
"Chrome Liquors and their Application," which, though 
short, contain the essential points of the subjects they 
deal with. Sets of model answers to the City and Guilds 
of London Institute's Examinations in Leather Dyeing, 
Staining, and Finishing will be useful both to students 
who are preparing for the examinations, and to practical 
men whose knowledge of certain aspects and details wants 
rubbing up or extending. Short abstracts from foreign 
journals and reviews of recently published books fill up the 
paper, for the success of which we may express cordial and 
confident hopes. 



Organic Chemistry. By A. E. Dunstan, B.Sc. London; 

Methuen and Co. 
This text-book of organic chemistry does not follow the 
syllabus of any particular examination, but gives a course 
designed for the higher classes in science and other schools 
and for the first year students in technical colleges. Suit- 
able practical work is included, both preparations and 
methods of identifying an organic compound being de- 



scribed. The book begins with a study of the preparation 
and properties of alcohol and its reactions. Then its 
oxidation and reduction products are described, as well as 
the principal characteristics of its homologues. These 
subjects occupy the first ten chapters. Then acetic acid 
is made the starting point of a fresh group of compounds 
— acid chlorides, nitriles, amides, &c. — and various typical 
reactions are explained. This centralising of all the 
beginner's knowledge round one compound is an excellent 
plan, tending to consolidate his ideas, and slight though 
the treatment of some reactions is, it is sufficient to give 
the student an idea of the main general reactions of 
organic chemistry. The later chapters of the book intro- 
duce many new classes of compounds, unsaturated dibasic 
acids, glycerols, carbohydrates, &c., and, in fact, this part 
is a little congested. However, this drawback could prob- 
ably be met by spreading the course over a longer period 
than a year, and allowing the student to supplement the 
book by the use of a larger treatise containing in particular 
more purely theoretical matter. 

Producer-Gas and Gas-Firing. By Ernest Schmatolla. 

London : Published by the Author. 1908. 
This booklet, which is an abridgment of the second 
edition of " Gas Producers and Gas-Firing," gives a sum- 
mary of the advantages to be gained by the use of pro- 
ducer-gas instead of coal in works employing furnaces. In 
it are described methods of making the gas and mixing it 
with air, and the results obtained with cheap fuels used in 
producers are compared with those given by high-class 
fuels used in the ordinary way ; without going into details 
or giving statistics the author makes it clear how great 
saving can be effected, while the efficiency of the furnace 
is by no means impaired. Undoubtedly it is in the ex- 
tended use of producer-gas that the solution of the smoke 
problem will in some degree be found, and such pamphlets 
as this are of great value in calling the attention of prac- 
tical men to improvements and economies which have 
been subjected to tests and have been found to be feasible. 



The Chemistry or Essential Oils and Artificial Perfumes. 
By Ernest J. Parry, B.Sc. (Lond.), F.LC, F.C.S. 
Second Edition. London : Scott, Greenwood, and Son. 
1908. 

The chemistry and technology of the essential oils are 
fully treated in this book, which has been considerably 
enlarged in preparing the second edition. The compounds 
contained in essential oils are first described, and the usual 
methods of preparing the oils are explained and illustrated. 
The analysis of the finished product is dealt with in outline 
only, no attempt being made to provide a laboratory guide 
for analytical work. The greater part of the book is 
occupied with the systematic study of the chemical and 
physical characteristics of the oils ; these are grouped 
according to the botanical relationships of the plants 
yielding them, which is, on the whole, the most satis- 
factory method of classification. An outline is given of 
the chemistry of artificial perfumes, and to the second 
edition an appendix has been added, showing in tabular 
form the requirements of the British and ten of the most 
important foreign Pharmacopoeias. 



Annuaire pour VAn igog public par le Bureau des Longi- 
tudes. (" Annual for the Year igog Published by the 
Longitude Bureau "). Paris : Gauthier-Villars. 
In accordance with the usual custom of alternating certain 
kinds of information each year this, the 113th volume of 
the Annuals issued by the Bureau des Longitudes, con- 
tains data relating to meteorology and geography and 
general statistics, in addition to the usual copious astro- 
nomical tables. The annual for igio will contain lists of 
physical and chemical constants. The astronomical tables 
are marvels of completeness, and in addition the annual 



Cmsmical News, ) 
Jan. 29, 1909 » 



Potential Energy of the Elements, 



contains two articles, one by G. Bigourdan on the variable 
stars, and the other by Ch. Lallemand on the movements 
and deformations of the crust of the earth. 



59 



CORRESPONDENCE. 

THERMO -CHEMICAL POTENTIAL 
AS A MEASURE OF CHEMICAL AFFINITY. 

To the Editor of the Chemical News. 
Sir, — The considerations which have led me to consider 
the elements as possessing thermo-chemical equivalents 
which are approximately correct when tested against the 
large mass of thermo-chemical data, also point direct to 
these equivalents being perhaps the readiest measure of 
chemical affinity. 

I select the four most common non-metallic elements, 
carbon, hydrogen, nitrogen, and oxygen, and quote the 
equivalents I have endeavoured to establish for these in 
previous numbers of the Chemical News (vol. xciii., 
et seq.). 

The high value given for oxygen at once shows the 
reason for water and carbon dioxide being the most stable 
of the ordinary compounds of these elements. 

Methane, ethane, and carbon monoxide, with heats of 
formation of a similar value, are approximately equally 
stable, ammonia (NH3) lying between these compounds 
and the nitrogen oxides in which I represent oxygen as 
penta-valent, and which are unstable compounds, nitrous 
oxide (N2O) being least so. 

In using the term thermo-chemical potential, I think it 
adequately supplies a connecting link between what at 
first I merely regarded as a heat exchange between the 
elements, and now consider as also a measure of affinity. 
— I am, &c., 

J. C. Thomlinson, B.Sc. 

January 19th, 1909. 



POTENTIAL ENERGY OF THE ELEMENTS. 

To the Editor of the Chemical News. 

Sir, — With reference to Mr. J. C. Thomlinson's letter 
(Chemical News, xcix., 34) in which he seeks to establish 
a relationship between the potential energy of the 
elements and their atomic weights, I venture to offer the 
following observations : — 

The atomic weights may be defined as the weights of 
masses which under similar conditions are similar 
functional of their absolute atomic potentials. A chemical 
combination is essentially the result of an interaction of 
potential energy, and the ratios of the weights of the 
elements taking part are simply functionals of the absolute 
values of potential concerned in such reaction. 

May I observe further that, in my view, Dalton's con- 
ception of the atom as a sphere surrounded by a zone or 
atmosphere of free energy has not received the attention it 
merits. 

We may conceive the zone to be composed of imponder- 
able (in the sense that it cannot be detected by the aid of 
a chemical balance) potential or unequilibrated energy, and 
to envelope a central nucleus of ponderable equilibrated or 
static energy. 

A ratio between these two fundamental states of energy 
admits of calculation, and affords an important factor in 
the estimation of the value of the potential energy of the 
element. This conception also furnishes data for an 
entirely different and more concrete view of the nature of 
chemical change than that now in vogue, but which I 
would prefer not to enlarge upon at present. — I am, &c., 

Daniel J. Rankin. 

Orleans House, Peterborough, 
January i8th, 1909. 



CHEMICAL NOTICES FROM FOREIGN 
SOURCES. 

NoTi,— All degrees of temperature are Centigrade unless otherwitc 
expressed. 

Berichte der Deutschen Chemischen Gesellschaft. 
Vol. xli.. No. 17, 1908. 

Synthesis of Alcohols of the Series C„H2„-5.0H— 
A. Reformatsky.— The action of allyl iodide and zinc on 
the esters of the halogen substituted acids in ethereal solu- 
tion may be regarded as a general method of preparing 
monatomic unsaturated alcohols of the seriesC,.H2-i-5. OH. 
Glycols or oxyacids or their lactones are also formed. The 
yields of alcohols and the corresponding condensation pro- 
ducts are in inverse proportion ; also the higher the 
molecular weight of the ester the smaller the amount of 
alcohol formed and the greater the amount of the condensa- 
tion product. The intensity of the reaction decreases as the 
molecular weight of the halogen substituted ester increases, 
and substituted esters of abnormal structure give poorer 
yields of alcohol and larger quantities of condensation pro- 
duct. The esters of brom-substituted acids react more 
energetically than those of chlor-substituted acids. All the 
alcohols of the series prepared by the author are colourless 
liquids smelling like the terpenes ; they are insoluble in 
water, and readily soluble in alcohol and ether. They are 
not appreciably oxidised in the air, but are readily 
brominated and oxidised by potassium permanganate. 

New Method of Formation of Liquid Alloys of 
Sodium and Potassium.— George F. Jaubert. — When 
potassium acts on caustic soda and when sodium 
acts on caustic potash, alloys of sodium and 
potassium are formed ; they may contain up to 80 
per cent of potassium. The chief reaction between 
K and NaOH may be expressed by the equation 
3K-|-NaOH = KOH-HNaK2, while between Na and KOH 
it is 3Na-t-2KOH = 2NaOH + NaK2, or, if less heat is 
applied, 2Na + KOH = NaOH -fNaK. Both the alloys 
NaK and NaKa are liquid. 

Chlorazide, N3CI.— F. Raschig.— When a solution of 
the sodium salt of hydrazoic acid, NsNa, is mixed with a 
solution of sodium hypochlorite and the mixture is acidified 
with a weak acid, such as acetic or boric acid, it turns 
yellow, and a colourless gas escapes, smelling of hypo- 
chlorous acid. The gas explodes when brought into contact 
with a flame or a glowing splinter. It is soluble in water, 
giving a yellow solution . The gas escapes from this solution 
at the ordinary temperature hi vacuo, and can be collected 
in caustic soda ; the solution thus obtained sets iodine free 
from potassium iodide, and bleaches litmus-paper. The 
composition of the gas is expressed by the formula 
N3CI, and the equation showing its formation is 
HOCl -f- N3H = UiO + N3CI, the action being similar to that 
of hypochlorite on ammonia, HOCl-f NH3 = H20-f NH2CJ. 
When the solution of chlorazide acts on caustic soda 
sodium hydrazide and sodium hypochlorite are formed. 

Chromium Compounds. — A. Werner and N. 
Costachescu. — Two fluorides of the hexaquochromium 
series exist, the normal [Cr(OH2)6jF3 and the esotri- 
hydrate [Cr(OH2)6] IOH2FJ3. They are both violet in 
colour. Two hexafluorochromates of the hexaquo series 
are known, namely, the normal [Cr(OH2)6j(CrF6) and the 
monoesohydrate [Cr(0H2)6i(CrF6) + H20. An isomer of 
the latter is trifluorochromium, which can be represented 

by the constitutional formula 2 T Cr^^*^3 j +1H2O. 
The three last chromium fluoride hydrates are given. 

Action of Phosphorus Pentachloride and Penta- 
bromide on Mercaptans. — W. Autenrieth and Alfred 
Geyer. — Pure phenyl and benzyl mercaptans react very 
violently at the ordinary temperature with both PCI5 and 
PBrs. When the mercaptan is cooled an energetic 
reaction also occurs, hydrochloric acid being evolved. 



6o 



Meetings for the Week. 



J Chemical News, 
( Jan. 29, 1909 



From quantitative experiments it has been found that the 
course of the reaction is expressed by the equation 
2C6H5SH + PCl5 = C6H5S.SC6H5 + PCl3 + 2HCl. Thus the 
products are PCI3 or PBr3, disulphide and hydrogen 
haloid. No by-products can be detected. 

Constitution of Disulphoxides. — O. Hinsberg. — The 
synthesis of ethyl disulphoxide by potassium ethylthiosul- 
phonate and ethyl bromide, — 

CaHs.SOz.SK + BrCaHs^CaHj.SOa.S.CaHs, 
seems to point to the fact that the disulphoxide has the 
asymmetrical formula, but the author points out that the 
alkyl thiosulphonates have undoubtedly the formula 
R.S(:0).S(:0).Randnot RSO.S.OMe as Gutmann assumed. 
When disulphoxides arc reduced, disulphides are formed, 
CioH7.SO.SO.CioH7.+ 4H = CioH7.S.S.CioH7f2H20,but 
although this seems to point to the symmetrical formula 
there is always the possibility that the reaction is com- 
plicated, occurring according to the equations — 
R.SO2.S.R + H2 = R.SO2H -l-R.SH, 
R.S02.H-»-R.SH-|-H2 = R.S.S.R-J-2H20. 
This assumption, however, appears to be contradicted by 
the regular course of the reduction process, while no 
sulphinic acid nor mercaptan can be detected. The author 
considers that the symmetrical formula of the disulphoxides 
is by far the most probable. 



MISCELLANEOUS. 

Institute of Chemistry. — Pass List, January Ex- 
aminations, 1909. — Of nineteen candidates who pre- 
sented themselves for the Intermediate Examination, the 
following eleven passed: — M. S. Baker; R. Boyd, B.Sc. 
(Glas.); W. G. Carey; H. S. Coupland, B.Sc. (Lond.) ; 
S. E. Crook; H. R. Lyell ; A. Marcan ; G. S. McKee ; 
F. J. L. Petri; J. Shelton ; and N. Garrett Smith. Eight 
candidates presented themselves for the Final Associateship 
Examination in the Branch of Mineral Chemistry, and 
three passed: — T. W. Harrison, B.Sc. (Lond); J. R. 
Hill, B.A. (Cantab.) ; and N. M. Hyslop. In the Branch 
of Metallurgical Chemistry, of two examined, one passed : 
—Charles Salter, Assoc. R.C.Sc, A.R.S.M. Of eight 
candidates who presented themselves in the Branch of 
Organic Chemistry, the following six passed. — H. T. 
Clarke, B.Sc. (Lond.); H. Davies ; J. G. Hay; V. J. 
Harding, B.Sc. (Mane.) ; G. Hogan ; and J. H Ryffel, 
M.A. (Cantab.), B.Sc. (Lond.). In the Examination in 
the Chemistry of Food and Drugs, and of Water, of nine 
who presented themselves, four passed : — W. Bacon, B.Sc. 
(Lond.); B. S. Evans, B.Sc. (Lond.); O. J. Patrick; 
and V. J. Tilley. W. Bacon and J. H. Ryffel were 
examined for the Fellowship. 

Royal Institution. — On Tuesday next, February 2, at 
three o'clock, Prof. A. A. Macdonell begins a course of 
three Lectures at the Royal Institution on "The Archi- 
tectural and Sculptural Antiquities of India." During the 
course the Buddhist, Hindu, and Muhammadan antiquities 
will be dealt with, and illustrated with lantern slides. Mr. 
William Archer is to give two Lectures, commencing 
February 11, on "The Revival of Modern Drama," in 
which its causes and problems will be discussed. On 
Saturday, February 6, Sir Alexander Mackenzie com- 
mences a course of three musical lectures, the first two of 
which will be devoted to Mendelssohn, and the remaining 
one to Chamber Music. The lectures will be musically 
illustrated with the kind assistance of the Hans Wessely 
Quartette. The Friday Evening Discourse on February 5 
will be delivered by Prof. J. G. Frazer on "The Influence 
of Superstition on the Growth of Institutions," and on 
February la by Prof. H. A. Wilson on "The Electrical 
Properties of Flame." The Discourse on February 26 will 
be delivered by Prof. H. L. Callendar on " Osmotic 
Phenomena" instead of by the Earl of Berkeley. 



ICssay Competition on Radium. — Young scientists 
connected by birth or residence with the county of Dorset 
will be interested in the essay-writing competition an- 
nounced in our advertising columns to day. The " Cecil " 
Medal and Prize will be awarded for the best Paper on 
" The Discovery of Radium ; Its Probable Origin, Present 
Development, and Possible Future Use." The competi- 
tion will be open to any person who was between the ages 
of eighteen and thirty on May 12th, igo8 (that being the 
date of the Annual Meeting of the Dorset Field Club, 
under whose auspices the competition is held), and who 
was either born in Dorset or had on May 12th, 1908, 
resided in the county for the previous twelve months. 
Papers for both medals must be clearly written, and may 
be illustrated by drawings or photographs, the personal 
work of the candidate. The committee attach great im- 
portance to original observation. Papers should be sent 
by March ist, 1909, to Nelson M. Richardson, Esq., 
Montevideo, near Weymouth. Further particulars may 
be obtained of the Assistant Secretary, Mr. H. Pouncy, 
Chronicle Office, Dorchester. 

NOTES ANU QUEHIES. 

',' Our Notes and Queiies column was opened for the purpose of giving 
and obtaining infoimalion likely lo be of use lo our leade's generally. 
We cannot undertake lo let this column be the means of transmitting 
merely private information, or such trade notices as should legitimately 
come in the advertisement columns. 

Coal-tar Acids. — Can any reader recommend a good book con- 
taining account of the separation and estimation of the various tar 
acids, &c., of coal-tar ?— Phenol. 



.MEETINGS FOR THE WEEK. 

Monday, Feb.. ist. — Royal Institution, 5. General Monthly Meeting. 

Royal Society ojf Arts, 8. (Cantor Lecture). 

" Public Supply of Electric Power in the United 
Kingdom," by G. L. Addenbrooke. 

Society of Chemical Industry, 8. " Gun-cotton 

and its Manufacture," by Col. Sir Frederick L. 
Nathan, R.A. 
Tuesday, and. — Royal Institution, 3. "Architectural and Sculptural 
Antiquities of India," by Prof. A. A. Macdonell. 

Royal Society of Arts, 4.30 " Production of Wheat 

in the British Empire," by Albert E. Humphries. 
Wednesday, 3rd. — Society of Public Analysts, 8. (Annual General 
Meeting!. " Use of Quartz Combustion Tubes, 
especially for the Direct Determination of Car- 
bon in Steel," by B. Blount and A. G. Levy. 
" Composition and Analysis of Chocolate," by 
P. A. E. Richards, C. H. Cribb, and N. P. 
Booth. " Some Commercial Samples of Mono- 
brombenzene," by J. H. Coste. 

Royal Society of Arts, 8. " The Problem of 

Unemployment," by Bolton Smart. 
Thursday, 4th.— Royal Institution, 3. "Revival of Modern Drama," 
by William Archer, M.A. 

Chemical, 8.30. "The Triazo-group— Part VII., 

Interaction of Benzhydroximic Chloride and 
Sodium Azide," by M. O. Forster. "The Triazo- 
group -Part VIII., Azoimides of the Monobasic 
Aliphatic Acids," by M. O. Forster and R. Miiller. 
" Nitro- derivatives of Ortho-xylene," by A. W. 
Crossley and Miss Nora Renouf. "Divergence 
of the Atomic Weights of the Lighter Elements 
from Whole Numbers," by A. C. G. Egerton. 
" Benzyl and Ethyl Derivatives of Silicon Tetra- 
chloride," by G. Martin and F. S. Kipping. 
"Constituents of the ^diik oi P rutins serotina — 
Isolation of /-Mandelonitrile Glucoside," by F. B. 
Power and C. W. Moore. " Mechanism of the 
Reduction of Nitro-anilines and Nitro-phenols''and 
"Relation between the Strength of Acids and Bases 
and the Quantitative Distribution of Affinity in the 
Molecule," by B. Fliirscheim. " Simple Notation 
for Indicating the Configuration of the Sugars and 
Allied Substances," by T. S. Pattereon. "Deter- 
mination of the Rate of Chemical Change by 
Measurement of the Gases evolved," by F. E. E. 
Lamplough. " Formation and Reactions of 
Imino-compounds — Part VIII., The Formation 
of Methyl Derivatives of i . 3-Diamino-2-phenyl- 
naphthalene from the three Tolylacetonitriles," 
by S. R. Best and J. F. Thorpe. " Effect of Con- 
jugated Unsaturated Groups on Optical Activity," 
by T. P. Hilditch. 
Friday, 5th.— Royal Institution, 9. " Influence of Superstition on the 
Growth of Institutions," by Prof. J. G. Frazer, D.C.L. 
Saturday, 6th.— Royal Institution, 3. " Mendelssohn " (with Musical 
Illustrations), by Sir Alexander C. Mackenzie. 



(Jhemical' News, 
Feb. 5, lycK) 



Action of PermctK^C'iate on Ferrous Sails. 



6i 



THE CHEMICAL NEWS 

Vol XCIX., No. 2567. 



THE ACTION OF PERMANGANATE 

ON FERROUS SALTS IN PRESENCE OF 

HYDROCHLORIC ACID. 

By W. COLET BIRCH, B.A., A.I.C. 

The following experiments were made with a view to 
obtaining some systematic knowledge of the effects ol 
dilution and concentration of acid on the reaction which 
takes place between ferrous salts and permanganate, when 
these substances are titrated in presence of hydrochloric 
acid, and also to ascertain, if possible, the cause of the 
attendant irregularities ; irregularities which seriously in 
terfere with the effectiveness of a reaction which would 
otherwise be of very wide use. 

It seemed, in addition, advisable to find out whether the 
process given by Liiwenthal and Lenssen (Zeit. Anal. 
Chem., i., 329), and Fresenius {Zeit. Anal. C/(«/m., i., 361), 
which appeared to have been insufficiently worked out, was 
capable of giving exact results. 

Statements occur in some books on volumetric analysis, 
apparently without experimental verification, to the effect 
that the presence of certain salts, e.g., ammonium sul- 
phate, manganese sulphate, entirely obviates the dis 
crepancies due to the hydrochloric acid. 

While the work was in progress a paper by Harrison and 
Perkin (Analyst, February, 1908) appeared, on " Titration 
with Permanganate in presence of Hydrochloric Acid," in 
which the addition of manganous sulphate or phosphoric 
acid to the solution before titration was shown to have 
little or no value. 

The disturbing effect of the hydrochloric acid is said to 
be due to its oxidation by the permanganate and the con- 
sequent evolution of chlorine. 

The following equations are given : — 

i. loFeOf Mn207 = 5Fe203 + 2MnO, 
ii. loHClf Mn207 = 2MnO + 5H20f 5CI2. 

It is very difficult to see how, if the last reaction were the 
only disturbing one, the presence of such salts as am- 
monium sulphate, or even manganese sulphate, could 
bring the results into the desired regularity. 

Fresenius's method consists in adding to the'solution, 
after the first titration has been carried out, an equal 
amount of the ferrous solution, re-titrating, and repeating 
the process three or four times in all. The titration is 
carried out in very dilute solution, and the mean of the 
second and third or third and fourth numbers is taken as 
correct. 

The following are two series of numbers taken from 
Fresenius's paper on the subject : — 

I Litre Water, 25 cc. HCl, 10 cc. FeS04. 
Cc. KMnOi required. 



First series. 


Second series 


13-9 


13-80 


i2'g 


1325 


12-9 


12-65 


12-8 


12-50 





12-62 





i2-6o 



The mean number found by titration in presence of 
sulphuric acid in the ordinary way was 12-8 cc. 

The numbers in the second row, at least, do not seem 
to agree closely enough to warrant the process being 
described as accurate. 

To prove the point a systematic series of titrations was 



3 


1) 









' 


t/1 






<u 




Q. 


u 




PC 


to 









bO 




vo 






u 


no 




■* 


c 


M 








bf) 




r, 






3 






£ 


r» 


< 





.-; 12 " > > d 



s S S "" 



c = 5 
ca rt " 



p 




t^ 0> r-» Tj- 

p CO a> p 


tH 


tH 00 m 


CO 

- 


m 


§ 






N in M N 

M M M M 


tH 
»H 


N w M 

»H M tH 


b b 
+ 1 


b 

1 


b 
1 


00 



t^ m -l- 

f< p^ CTi p 1 


1 


00 <s o> 


8^ 


? 


00 


M 


M 


M M N 1 
M M M 


1 


PI »- w 

tH tH tH 


b b 

1 


b 
1 


b 

1 


00 




0> in moo 
N p p p t^ 


en 

p^ 


t>- N PI 

" ? P 


g'^ 


^ 


? 


M 




N M N M 
M M M M 


M 

»H 


PI PI N 

IH IH M 


b b 
+ 1 


b 
1 


b 
1 


N 

P 


00 


in t^ mo 

p 00 p> o> 


1 


(O 


^^ 


c« 


en 



H 


"rt- 

M 


^ m CO CO 

M M M M 


1 


M IH M 


b b 
•t 1 


b 

1 


b 

+ 







■»!- ro CO 

p> c^ o^cp 


PI 


p p\p\ 


^S" 


M 


^ 


Tl- 


'•*• 

w 


CO ro en en m 

M M M t-t #-4 


Vj- tn on 

M »H M 


b b 

■i- 1 


b 
1 


b 
1 


P 




(N N 

p p^ o> p 


in 

p 


IH VO PI 


r^oo 




PI 

M 





M 




■^ rn CO V 

M M IH M 


'•* 


V tn cn 

M IH M 


b b 
+ 1 


b 

1 


b 

1 


■<J- 
p 


•n N 10 w 

Op 00 CO p 00 


01 


PI IH CO 

tnoo o> 


00 en 

M PI 


M 
M 




M 


*•* 

M 


m fo -^ fo m 

M M M M M 


V fO fO 

M M IH 


b b 
+ 1 


b 
1 


b 


S- 


f^ u-1 iri 00 CTi 

mco 00 lO ■* CTi 


IH in N 
PI 00 PI 


t-^ cnoo 


C3> 

IH 




'•*■ 


m cr-, ■>)■ cn m 

M t-t H M M 


V rn V 

M IH M 


b b 
+ 1 





b 

1 


10 

P 


00 U-) 
CI P P) 0> M 


8 


Tj- Th t^ 

r r P 


g'g^ 


PI 



? 




Tt- 


■^ -"i- m Tj- 


V*- 

tH 


''^ V '■* 

IH M IH 


b b b 
+ + + 


b 


in 

p 


cn 00 t^oo 
w N en o^ 


M •* PI 
PI M p 


VO CTi CO 

-1 


in 

IH 


M 




■* •* m ro 

l-l l-t t-t »H 


^ 

M 


V '-^ V 

M IH M 


b b 
+ t 



1 


b 

+ 







u-i 


t^ m inoo 

_T^ N M N 


1 


00 10 


00 Tj- 
PI 


B- 


ii") 


in 


in m >n in 

tH t-t »H t-t 


1 


m m m 


b b 
+ 1 



1 


b 

+ 




VO 

p 


•n ro r^ m 


m r~<0 

lO i-i t^ 


00 


IH 


p« 
PI 


in 


vb 


in >n in m 

t-l (H M tH 


in 


in m in 

M IH IH 


b b 
+ 1 


b 

1 


b 

1 



in in in in in in 



in in in in in in 



in in in m m in 



■ -1 

. _3 


in 

'. "v 

fa 




s . 




O O o 



ii o -5 

1- '^ 3 



S S 3 

o - H 



c 



M 


"o 


PI 


'0 


PI 




n 


c 





c 













n 






tn 


c 



- 










"(U 


•3 


■a 

CD 


•o-o 


^ 


U< 


13 


13 


rt 


j= 


rt 


u 


In 






•a 

iH 


3 


J3 





.^ 


s: 







fa 


cflHfafa 



4> •= 






^2 



A ction of Permanganate on Ferrous Salts. 



Chemical News, 
Feb. 5, 1909 



Table II. 
Volume in cc. of HCl containing 

293-9 grms. per litre 

Volume of solution when titration 

was started 

Volume of MgS04 solution con- 
taining 246 grms. crystallised salt 
per litre 

True value 

20 cc. Fe" solution 

First addition of 20 cc 

Second addition of 20 cc 

Third addition of 20 cc 

Fourth addition of 20 cc 

Fifth addition of 20 cc 



50 



Table III, 

Volume in cc. of HCl containing 

2939 grms. per litre 50 

Volume of solution when titration 

was started 1000 

Volume of Na2S04 containing 142 

grms. anhydrous salt per litre . . 200 

True value 12-21 

20 cc. Fe" solution i3'39 

First addition of 20 cc i2*35 

Second addition of 20 cc ii'95 

Third addition of 20 cc 12-03 

Fourth addition of 20 cc 12-13 

Fifth addition of 20 cc 12-02 



Table IV. 
Volume in cc. of HCl containing 

293-9 grms. per litre 

Volume of solution when titration 

was started 



50 
1000 



Volume of (NH4)2S04 solution con- 
taining 132 grms. (NH4)2S04 per 
litre 

True value 



20 cc. Fe" solution . . 
First addition of 20 cc. . 
Second addition of 20 cc. 
Third addition of 20 cc. , 
Fourth addition of 20 cc. . 
Fifth addition of 20 cc. . 



50 
1000 



i3"45 


I3"45 


13-45 


1452 


14-79 


13-55 


13-69 


1336 


13-40 


13-35 


13-46 


13-40 


13-08 


13-29 


13-40 


i3-4« 


13-43 


— 


I3"4i 


1336 


— 



50 





1000 


lOGO 


100 


100 


12-21 


12-21 


13-56 


12-42 


12-69 


12-20 


"•57 


12-12 


11-95 


12-19 


12-03 


— 


11-93 


— 



50 



13-45 


13-45 


13-45 


14-95 


14-89 


13-62 


14-23 


14-65 


13-34 


13-86 


13-88 


13-34 


13-86 


13-86 


— 


13-bI 


13-77 


— 


13-78 


13-73 


— 



carried out in which the amounts of hydrochloric acid and 
the dilution were varied. 

The numbers obtained are tabulated in Table I. The 
approximately decinormal permanganate solution was 
titrated with the ferrous solution in presence of sulphuric 
acid alone every day before work was begun, the numbers 
obtained appearing in the " true value" row of Table I. 

It will be seen from the table that the mean of rows I. 
and II. is always too large, and that of rows II. and III. 
and of all the succeeding titrations taken in pairs is, in 
general, too small. 

Further, there appears to be no special advantage in 
taking means at all, the second titration of every series 
being as good an approximation to the " true value " as the 
mean of the second and third or third and fourth. 

The numbers, as will be seen from the rows containing 
the differences, are not in close enough agreement with 
the true value to warrant the process being used to give 
any but very approximate results. 

It is also apparent that very small amounts of hydro- 
chloric acid have considerable effect on the titration, and 
also that the influence of dilution is very small. 

The results are, if anything, slightly better in con- 
centrated than in dilute solution ; a fact opposed to the 
general idea that titration in presence of hydrochloric acid 
should only be carried out after diluting largely. The 
subject is complicated by the difficulty of obtaining a sharp 
end-point. 

After the titration has been started the solution turns 
yellowish green, and a chlorinaceous smell is noticed. 

The colour change on completion of the titration is to a 
reddish brown instead of to the usual clear pink tinge. 

As might be expected, the change becomes less and less 
easy to see as the amount of manganous and ferric salt 
increases. Increase of concentration has the same effect, 
and in the column left blank in Table I. there was no 
visible end-point. 

II. Titration in presence of Various Salts. 

(a) Magnesium Sulphate. — Table II. shows the results 
obtained when a strong solution of magnesium sulphate 
was added before titration. It appears to have no effect 
at all. Throughout the titrations a strong chlorinaceous 
smell was noticed. 

(b) Sodium Sulphate (Table III.). — This salt is also 
without effect. 

(c) Ammonium Sulphate (Table IV.). — In this case the 
results are not only no better, but actually worse. The gas 
evolved had quite another smell than chlorine, and was 
reminiscent of chlorine monoxide. It is not surprising that 
the results in this case should all be too large, since 
chlorine acts with considerable ease on ammonium salts, 



Volume in cc. of HCl conlaining 293-9 
grms. per litre 

Volume of solution when titration was 
started 

Volume of MnS04 solution containing 
150 grms. crystallised salt per litre 

True value 

20 cc. Fe" solution 

First addition of 20 cc 

Second addition of 20 cc 

Third addition of 20 cc 

Fourth addition of 20 cc 

Fifth addition of 20 cc 



Difference of mean of II. 
true value 



and III. from 



Table V. 
50 50 50 50 50 50 50 50 

1000 1000 1000 1000 1000 1000 1000 1000 



200 


150 


100 


50 


25 


25 


10 









13-47 


13-47 


13-47 


13-47 


13-47 


13-47 


13-47 


13-47 






13-66 


13-66 


13-61 


13-73 


13-87 


13-82 


13-74 


14-43 




I. 


13-40 


i3-4« 


13-52 


13-49 


13-52 


13-46 


13-03 


13-64 




II. 


13-43 


13-47 


13-45 


13-40 


13-29 


13-43 


13-50 


J3-51 




III. 


13-46 


13-35 


13-45 


13-48 


13-40 


13-39 


13-32 


13-26 




IV. 


13-24 


13-44 


13-45 


13-37 


13-33 


13-31 


13-47 


13-45 




V. 


13-46 


13-32 


13-36 


13-39 


13-44 


13-48 


13-27 


13-45 




VI. 


















Mean of — 


13-53 


13-57 


13-56 


13-61 


13-69 


13-64 


13-37 


14-03 


I. 


and II. 


13-41 


13-47 


13-48 


13-44 


13-40 


13-44 


13-26 


13-57 


II. 


and III. 


13-44 


13-41 


13-45 


13-44 


13-34 


13-41 


13-41 


13-38 


Ill 


. and IV 



—0-06 o"oo +o*oi -0-03 —0-07 —0*03 —0-21 +0-I0 



Chemical News, I 
Feb. 5, 1909 I 



Osmotic Pressure of Concentrated Solutions. 



63 



giving nitrogen trichloride to which the pungent smell may 
have been partly due. 

(d) Maiifranese Sulphate (Table V.). — There is no doubt 
that if particular care is taken to standardise the per- 
manganate under approximately the same conditions as 
will obtain when the unknown ferrous solution is titrated, 
the strength of an iron solution can be obtained even in 
presence of hydrochloric acid, if a considerable excess of 
manganous sulphate is first added (Hauffe, Chem. Zeit., 
1897, xxi., 894; Willenz, Chem. Centr., 1899, i., 638). 
In order to ascertain if numbers could be obtained which 
would agree with the titre of a ferrous solution found in the 
ordinary way, in presence of sulphuric acid alone, a series 
of titrations was carried out in which a varying amount of 
manganese sulphate was added to the mixture before 
titration. Twenty cc. of the ferrous solution were mixed 
with 50 cc. HCl and 25 cc. of dilute H2SO4, the MnS04 
added, and the volume of the solution brought up to i litre 
with distilled water. 

Table V. contains the numbers found. It will be seen 
that the mean of II. and III. agrees well with the true value, 
provided there is a fair amount of manganese salt present. 

This method of working, therefore, gives fairly good 
results, but it is cumbersome, owing to the large amount 
of solution to be dealt with, and also inconvenient owing 
to the necessity for having enough iron solution to serve 
for three titrations. 

The colour change, as was the case in the first series of 
titrations, is peculiar, a brown tint being taken to mark 
the disappearance of the last trace of ferrous salt. 

The end-point is at first well marked, but becomes more 
and more indefinite as the amount of ferric salt increases. 

In one case in which the solution was only diluted to 
250 cc. there was no visible end-point, the solution 
gradually darkening to brown. 

In general, no smell of chlorine was noted, but in the 
two cases in which 25 cc. of manganous solution were 
added, there was a very slight one, and in the case with 
10 cc. the smell was very distinct. 

It seems probable that the manganous salt keeps the 
chlorine from escaping from the solution with the conse- 
quent formation of a brown compound, rather than that it 
prevents the reaction between the hydrochloric acid and 
the permanganate from taking place. 
(To be continued). 



THE OSMOTIC PRESSURE OF 

CONCENTRATED SOLUTIONS, AND THE LAWS 

OF THE PERFECT SOLUTION.* 

By GILBERT NEWTON LEWIS. 

(Continued from p. 53). 

In Table IV. the osmotic pressures of cane-sugar solu- 
tions are calculated from Equation 7. The first column 
gives the weight normal concentration ; the second, the 
volume normal ; the third, Ni, the mol. fraction of solute ; 
the fourth, the osmotic pressures calculated by the van 't 
Hoff equation ; the fifth, those calculated by the equation 
of Morse and Frazer ; the sixth, those calculated by 
Equation 7 ; the seventh, Morse and Frazer's observed 
values. 

While the values given by the equation of van 't Hoff 
differ from those observed by nearly 25 per cent at the 
higher concentrations, it will be seen that the pressures 
given in the fifth and sixth columns agree throughout with 
the observed values, within the limits of experimental 
error, and differ from each other by only i per cent even 
at normal concentration. 

This agreement between the osmotic pressures calcu- 
lated from the equation of Morse and Frazer and those 

♦ From the Journal of the American Chemical Society, xxx., No. 5. 



calculated by Equation 7 will always be found at moderate 
concentrations, as the following considerations show. The 
second term in Equation 7, except at the very highest 
concentrations, is comparatively insignificant, amounting 
usually to only a few per cent of the value of n even when 
the osmotic pressure is as high as a uxxj atmospheres. 
At moderate concentrations we may therefore neglect 
this term and write Equation 7 in the form — 

n» - ^ln{i-m) 8. 

» o 

Now the equation of Morse and Frazer may be written in 
the form — 

„ RT / N, \ 

for — l— is the number of mols. of solute to one mol. 
I Ni 

of solvent and Vo is the volume of one mol. of pure solvent. 

Equation 8 developed in series gives — 

n ^ ^(ni-i-£ Nr-fi Nx^+ . . . .) 

Vo \ 2 3 / 

and, similarly, Equation 9 gives — 

n = -^ (Nx + N:»+Nj«+ ....). 

These equations differ only in the higher powers of Ni, 
and therefore give identical results at such concentrations 
that the terms containing these higher powers are negligible. 
When the mol. fraction of the solute is 0-02 the values of 
n calculated from these equations differ by i per cent. 
For all more dilute solutions, therefore, the osmotic pres- 
sure of a perfect solution may be calculated within i per 
cent from the equation of Morse and Frazer. 

At higher concentrations, however, the difference between 
these two equations becomes very great, as is shown in 
Tables V. and VI. Table V. deals with solutions of 
ethylene chloride in benzene, and simply re-states in a 
new way the facts brought out in Table III. Table VI. 
contains data on solutions of propylene bromide in ethylene 
bromide. In both tables the first column gives the mol. 
fraction of solute; the second, the partial vapour pressure 
of the solvent, taken from the work of Zawidski (omitting 
the values which the author marks as questionable) ; the 
third, the osmotic pressure calculated by the van 't Hoff 
equation ; the fourth, that calculated by the equation of 
Morse and Frazer ; the fifth, that calculated by Equation 7, 
while the last column gives the actual osmotic pressure 
obtained thermodynamically from the vapour pressures by 
means of Equation 3. The molecular volumes of benzene 
and ethylene chloride at 50° are taken, respectively, as 
0092 and 0-082 litre, and the coefficient of compressibility 
of benzene as oooor. The molecular volumes of ethylene 
and propylene bromides at 85° are taken, respectively, as 
0092 and 0113 litre, and the coefficient of compressibility 
of ethylene bromide as 0-00006. 

We see from these tables how closely in these two cases 
the actual osmotic pressures agree with those calculated 
by Equation 7, and how far from the truth are the pres- 
sures calculated both by the van 't Hoff equation and by 
that of Morse and Frazer. These two solutions are, 
according to our definition, perfect solutions, within the 
limits of experimental error, for all concentrations from o 
to over 90 per cent of solute. Since, moreover, these 
cases are not unique but have been chosen out of a large 
number of similar cases merely because of the greater 
experimental care with which they have been investigated, 
it is to be presumed that even those solutions which are 
not perfect at all concentration will, on the average, follow 
the law expressed in Equation 7 to higher concentrations 
than they will the law of van 't Hoff or that of Morse and 
Frazer. 

In view of the experiments of Morse and Fi:azer, it has 
recently been proposed that in the ordinary equations of 
chemical equilibrium the concentrations expressed in the 



64 



Atomic Weights of Nitrogen and Silver. 



[Chemical News, 
I Feb. 5, 1909 













Table IV. 








Concentration, 


Concentration 




Mol. fraction of 




n 


n 


n 


n 


weight normal. 


volume normal 




solute. 




van 't Hoff. M 


Drse and F 


razer. Lewis. 


observed. 


O'l 


0-098 






o-ooi8o 




234 


2-41 


2-41 


2-40 


0-2 


0-192 






0-00358 




4-58 


4-81 


4-80 


474 


03 


0-282 






000537 




673 


723 


7-21 


723 


04 


0-369 
0-^452 






0-00715 




8-8i 


964 


9-60 


967 


0-5 






0-00892 




IO-8 


120 


120 


I2-I 


06 


0532 






0-0107 




12-7 


14-5 


14-4 


14-4 


07 


o-6io 






00124 




14-5 


i6-8 


167 


16-9 


0-8 


0-684 






00142 




16-3 


19-3 


19-2 


19-4 


o-g 


0-756 






0-0159 




18-1 


21-7 


21-5 


21-8 


i-o 


0-825 






0-0177 




19-7 


24-1 


23-9 


24-5 












Table V. 
















C2H4CI 


2 in 


CeHo at 50°. 
















n 




n 




n 


n 


Ni. 




^2. 




van't Hoff 




Morse and Frazer. 


Lewis. 


found. 


o-o 


268 





— 




— 




— 


— 


0-293 


I 


89 


8 


91 




120 




lOI 


100 


o'4i6 


I 


56 





128 




205 




157 


158 


0-522 


I 


-7 


8 


160 




315 




215 


217 


0-657 




92-4 


196 




549 




313 


310 


0-754 




65 


9 


223 




880 




413 


406 


0-920 




21 


8 


268 




3290 




743 


735 



Ni. 
o-o 
0-147 

0-222 
0-298 
0-412 
0-526 
0-620 
0720 
0-800 

o-86o 
0-915 



172-6 

1451 
132-2 
121-1 

lOI-I 

81-9 

64-0 

480 

343 
235 
13-8 



Table VI. 
C^UbQxi in C2H4Br2 at 85°. 

n 

van't Hoff. 



47 
69 

90 
121 
150 

173 
198 
218 
232 
241 



n 


n 


n 


and Frazer. 


Lewis. 


found 


55 


51 


55 


91 


80 


86 


136 


"3 


114 


224 


171 


173 


351 


241 


240 


520 


313 


319 


820 


412 


414 


1280 


522 


525 


i960 


640 


649 


3440 


806 


827 



volume normal system should be replaced by those ex- 
pressed in the weight normal system (Walden, Zeit. Phys. 
Chem., Iviii., 500 ; this paper also contains a letter from 
van 't Hoff on this subject). This is undoubtedly an im- 
provement, but the equations thus obtained are not entirely 
correct, even when all the substances concerned are present 
as perfect solutions. 

In order to find an exact equation, let us consider a 
reaction occurring as follows : — 

xiS.i-\-X2i^2-\r . , = .^3X3 + ^4X4-1- . , , 

where xt mols. of Xi combine with xz mols. of X2 to form 
x^ mols. of X3, &c. It is readily seen from the considera- 
tions advanced in this paper and from the thermodynamic 
laws of chemical equilibrium (Lewis, loc. cit., Equation 
XXIII.), that the general equation of chemical equilibrium, 
regardless of the concentrations of the reacting substances, 
provided that they are all present as perfect solutions, is 
as follows : — 

N3^8N4*4 



Ni*iN2*-2 



= K (a constant) 



where Ni, N2, &c., are the respective mol. fractions of 
Xi, X2, &c. 

This, then, is the form which the mass law assumes 
when the substances concerned form perfect but not 
infinitely dilute solutions, and for such cases it is rigorously 
exact. 

(To be continued). 



FURTHER INVESTIGATION OF THE 
ATOMIC WEIGHTS OF NITROGEN AND SILVER.* 

By THEODORE WILLIAM RICHARDS, PAUL KOTHNER, 
and ERICH TIEDE. 

(Continued from p. 56). 

The Final Preparation and Wei-ghing of Ammonium 
Chloride. — The ammonium chloride, as prepared by the 
methods described in the preceding section, was exceedingly 
pure, except from the presence of water and the doubt as 
to whether the substance had attained exact neutrality. 
These two doubts, however, would be enough to vitiate 
the whole work, provided that they were not removed — for 
the presence of water is just as serious, weight for weight, 
as the presence of any other substance ; and it would 
be indeed foolish to spend much thought on eliminating 
traces of sodium, for example, while leaving much larger 
weights of water in the final material. Again, an excess 
of ammonia or hydrochloric acid would have an equally 
pernicious eflfect upon the results. The presence of either 
would obviously be very much worse than the presence of 
equal amounts of sodium chloride. 

Taking this into account, it was obviously necessary to 
dry thoroughly the ammonium chloride, and sublime it in 
such a way as to insure, as definitely as possible, the 

♦ Journal of the American Chemical Society, xxxj., No, . 



Chemical News, 
Feb. 5, 1909 t 



Atomic Weights of Nitrogen and Silver, 



65 



-e 




Fig. r„ 



proper proportion of acid and volatile alkali. Ammonium 
chloride is an especially convenient substance to use as 
the basis of an atomic weight determination, because it is 




so easily sublimed. In this way it may be purified, and, 
moreover, an admirable test is furnished by sublimation, 
enabling one to determine whether or not non-volatile 
impurities are eliminated. Unfortunately, however, as is 
well known, the substance ordinarily sublimes by transition 
into a dissociated state, and the experimenter can never 
be certain that during the sublimation in another gas a 
portion of the lighter gas, ammonia, has not escaped, 
because of its more rapid diffusion. Sublimation brings 
with it a further difficulty common to most cases of the 
kind, namely, dangerous interaction between hot gases and 
the vessels in which the operation must be conducted. 
Hence, although sublimation furnishes an admirable means 
of leaving behind non-volatile impurities, it must be used 
with caution, especially in this particular case. 

Turning first to the latter cause of danger, we found by 
preliminary experiments that for this purpose both hard 
glass and platinum are unsuitable — each being attacked 
sufficiently to endanger the purity of the product. On 
the other hand, repeated experiments proved that fused 
quartz is entirely resistant to ammonium chloride, ammonia, 
and hydrochloric acid at the temperatures needed in the 
present work, and accordingly it alone was used wherever 
ammonium chloride came in contact with the containing 
vessel. (We take this opportunity for thanking the firm 
of Heraeus in Hanau for their kindness in furnishing some 
of the quartz apparatus with great promptness at one crisis 
in the experimentation). 

The best method of avoiding the former cause of 
uncertainty and inexactness seemed to be the following : — 
Every sample of ammonium chloride was sublimed twice, 
once in a current of ammonia gas in order to prevent the 
possibility of the existence of free acid, and again in a 
Sprengel vacuum in order to insure the elimination of the 
extra ammonia. 

The three quartz tubes used for the double sublimation 
were shaped in such a way that the first yielded its product 
into the second, and the second yielded its product into i\\^ 



66 



A tomic Weights of Nitrogen and Stiver. 



I Chemical News, 
1 Feb. 5, 1909 



third, which in turn could be used directly for the weighing 
of the preparation. 

The difference in treatment involved different apparatus 
in the two cases. For sublimation in a current of ammonia 
the apparatus shown in Fig. i was employed. In a was 
placed a concentrated solution of calcium chloride saturated 
with the purest ammonia gas. By heating this solution a 
continuous stream of fairly dry ammonia gas may be 
obtained. This was further dried by means of purest lime 
in towers f^ and f^ . Cotton-wool in the upper stopper of 
the second tower served to hold back powdered lime which 
might have been swept along, and at p was a glass tube 
containing a porous porcelain diaphragm filter — according 
to Stock (Ber., 1907, xl., 4956). The complete absence of 
dust was found to be necessary in order to prevent con- 
tamination of the product. Hence these special pre- 
cautions were taken, and, moreover, the complete elimina- 
tion of rubber connections was effected by fusing or 
grinding the tubes together. 

The substance to be sublimed was placed in a small tube, 
d (shown also on a larger scale on the right-hand side of 
the figure), and upon this tube was placed a somewhat 
larger glass tube b which was heated by means of a suitable 
magnesia tube wound with resistance wire. The excess of 
ammonia which flowed through ths apparatus during the 
sublimation escaped from the small hole at the top of ^. 



ports this value, and it is worth while now to describe the 
apparatus by which the conclusion was tested. This 
apparatus was a modification of the familiar bottling 
apparatus which has served for so many researches in 
Harvard University. In the present case the apparatus 
was modified for use in a vacuum, and the details are 
sketched in Fig. 3. The projectile-shaped boat or 
receptacle 2, filled with ammonium chloride in the manner 
just described, was placed in a hard glass tube, x. This in 
turn was ground into a tube similar to the familiar 
bottling apparatus except that its side excrescence was 
elongated so as to contain a small glass hammer as well as 
the cap-stopper of the weighing tube r. After the air had 
been wholly removed, the apparatus was disconnected from 
the pump and tilted. Thus the ammonium chloride with 
its container, z, was allowed to glide into the weighing 
bottle, r, and the cap, already carefully provided inside 
with a thin film of lubricant, was allowed to fall into place. 
The weighing bottle was finally securely closed by means 
of gentle blows of the small glass hammer h. It was cus- 
tomary to heat the ammonium chloride almost to sublima- 
tion before disconnecting the pump. When the weighing 
bottle was effectually sealed, dry air was admitted to the 
apparatus, and the weighing bottle removed to the desic- 
cator and weighed at leisure. Afterwards dry air was 
admitted and the tube was weighed again later ; when the 




Fig. 

It was easily possible to regulate the sublimation so that 
most of the solid material deposited within the quartz tube 
e, for the condensation occurs in the zone just beyond the 
hotter part of the tube, as the preliminary experiments had 
demonstrated. 

The final purification by sublimation in a vacuum took 
place immediately after this by fitting into the tube (e), 
after it had been removed from the apparatus just described, 
a third quartz tube, named z in Fig. 2. This was of a 
projectile-like shape, oped at both ends, and small enough 
to fit into the weighing bottle, which formed its final 
resting place. 

The arrangement of the apparatus for the second sub- 
limation is shown in Fig. 2, its form having been devised 
by degrees with the help of many unsuccessful attempts. 
The tubes containing the ammonium chloride, e and z, 
were placed in a larger tube, y, made of the hardest Jena 
glass. This larger tube was closed above with a ground 
glass cup, provided with a glass stopcock for connecting 
with a mercury air-pump. After the complete exhaustion 
of the tubes, the sublimation was conducted with the help 
of the electric heater. A lead tube with running water 
cooled the sublimate, so that a sufficient amount of it was 
deposited on the inner wall of z. Prepared in this way 
ammonium chloride deposits itself in beautiful diamond- 
like crystals, which become clouded only upon cooling, and 
are then pure white. No residue was left in the tube e. 
All the material used in the analyses was sublimed twice 
in this way. 

Stas has shown that ammonium chloride gains more 
weight when it is weighed in a vacuum than would be 
expected from its weight in air and its specific gravity. He 
found that i grm. of ammonium chloride under ordinary 
atmospheric conditions weighs -f 000080 more in a vacuiim 
than in air (Stas, " Untersuchungen," Aronstein's trans- 
lation, 1867, p. 56). The present experience entirely sup- 



ammonium chloride had been dissolved away, the weighing 
bottle and quartz container were exhausted in a similar 
way and once more weighed, both evacuated and filled 
with air, using the same closed counterpoise in each case. 
Thus the weight of ammonium chloride in vacuum was 
determined directly, and the vacuum correction could 
be easily calculated. After Stas's vacuum correction had 
been verified, time was saved for many of the analyses by 
simply weighing the ammonium chloride in air by means 
of the usual bottling apparatus without the additional 
heating and confining in a vacuum. 

(To be continued). 



Royal Institution.— A General Monthly Meeting of 
the Members of the Royal Institution was held on the 
ist instant, Sir James Crichtrn-Browne, M.D., F.R.S., 
Treasurer and Vice-President, in the Chair. Mr. W. E. 
Lake, Dr. A. Liversidge, Dr. K. C. E. von Martius, and 
Mr. F. J. Sharpe were elected Members. The Treasurer 
announced that the sum of ^10,000 had been anonymously 
and unconditionally placed at the disposal of the Managers 
for the purposes of the Institution by a lady ; and the 
Members passed a resolution expressing their most grateful 
appreciation of her munificence and discernment, accepting 
the gift as a timely and noble recognition of the good 
public woiks the Institution has done in the past, and is 
still doing, in the acquisition and diffusion of scientific 
knowledge, and as an mcitement to maintain and extend 
its usefulness in the unique position which it has for more 
than a century occupied. The Honorary Secretary re- 
ported the decease of Dr. Francis Elgar, F.R.S., a late 
Manager, and a Resolution of Condolence with the family 
was passed. 



Chemical News, ) 
Feb. 5, 1909 ) 



International Committee on Atomic Weights. 



67 



PROCEEDINGS OF SOCIETIES 

CHEMICAL SOCIETY. 
Ordinary Meeting, January 21st, 1909. 

Sir William Ramsay, K.C.B., F.R.S., President, 
in the Chair. 

The minutes of the previous meeting having been read 
and confirmed, Dr. Divers made the following inquiries : 
— Whether one of the objects of the resolution adopted by 
the Council " to remove some of the disabilities experienced 
by women chemists " were not, as it appeared to be, to let 
duly qualified women be " accepted " to enjoy privileges in 
the Society which men, similarly qualified, were not to be 
permitted to enjoy on the same terms, and, that being so, 
whether that object was a just and lawful one ? Whether 
the Council, in taking upon itself to "enact a regulation" 
(Charter, p. 6) indistinguishable in form and substance 
from a by-law, had avoided exceeding its powers merely by 
not proceeding to call the regulation a by-law ? In what did 
the resolution concerning Subscribers of the Society differ 
from the existing by-law for Associates, except in that an 
Associate must have passed a ballot of the Fellows ? Was 
it not clear from the Charter that any action by the Council 
on the resolution would be invalid until the vote of a 
General Meeting should have made the resolution into a 
by-law ? Whether the Council must not be exceeding its 
powers in legislating for women in any way whatever, if it 
were indeed the case that it would be going beyond its 
powers were it to accept women as candidates for the 
Fellowship, they being, it was said, outside the considera- 
tion of the Charter ? Would not even a General Meeting 
be exceeding its much greater powers were it to attempt 
to frame quasi-by-laws for those to whom the Charter did 
not apply? Did the Council in its words "disabilities 
experienced by women " refer to its assumption that 
the Charter really imposed upon it disability to receive 
the candidature of women for the Fellowship ? If so, did 
it need to be pointed out that disabilities, like any other 
ordinances, were not " experienced " by anyone, but were 
imposed, and that a Charter did not attempt to limit the 
powers of any man or woman who was not enjoying the 
privileges which it bestowed ? In speaking of " removing 
disabilities" did the Council maintain that it could itself 
escape from or could relieve others of a disability laid upon 
it or upon them by the Charter ? Lastly, was it to be 
understood that the Council believed, what its words im- 
plied, that it would be removing disabilities by granting 
privileges, supposing that it really could do either of these 
things ? 

Messrs. N. C. Akers, J. Brown, R. F. Easton, C. 
Everitt, A. F. Girvan, C. L. Norman, G. E. Pearson, 
W. B. Shaw, W. G. Winterson, and F. P. Worley were 
formally admitted Fellows of the Society. 

The President announced a proposal by the Institution 
of Gas Engineers to perpetuate the memory of the late Sir 
George Livesey by establishing a Livesey Professorship in 
Gas Engineering and Fuel at the Leeds University ; con- 
tributions to the Fund should be addressed to the Secretary 
of the Institution of Gas Engineers, 39, Victoria Street, 
Westminster. 

Certificates were read for the first time in favour of 
Messrs. Alfred Bertram Coles, M.A., 42, Broadwater 
Road, Tottenham, N. ; John Thomas Fox, Glen Burn, 
Stollard Street, Clay Cross, near Chesterfield ; John 
Thomas Furnell, 32, Grosvenor Park Road, Walthamstow ; 
Alfred George Cooper Gwyer, Ph.D., B.Sc, Keate House, 
Durdham Down, Bristol ; Robert Main Harland, 296, 
Willesden Lane, Willesden Green, N.W. ; Henry 
Humphreys Jones, 18, Colquit Street, Liverpool ; Horace- 
Keeble, Wereham, Stoke Ferry, Norfolk ; Joseph 
Leedham, 176, Bromford Lane, West Bromwich ; William 



George Martin, B.Sc, Royal School, Armagh ; Robert 
Robinson, M.Sc, Field House, Chesterfield ; Herbert 
Rogers, Stenning House, Cobwell Road, Retford, Notts ; 
J. H. Charles Schulten, Ph.D., 4, Pollock Street, Calcutta; 
Guy Ransom Warwick, B.A., 5 and 6, Fowkes Buildings, 
Great Tower Street, E.C. ; Percy Ch-rles Henry West, 
40, The Green, Norton, Co. Durham ; Thomas Jabez 
Wild, Scott's Laboratories, Southall, Middlesex. 

The Council has ordered the following letter and report 
to be printed in the yournal and Proceedings of the 
Society : — 

Government Laboratory, 

Clement's Inn Passage, Strand, London, W.C., 

October 29th, 1908, 

Gentlemen, — I beg to forward you, for presentation 
to the Council of the Chemical Society, the Report of the 
International Committee on Atomic Weights, 1909, to 
which I have affixed, as desired by them, the signatures 
of Professors Ostwald and Urbain. 

The general revision of the values of the atomic weights 
of the elements, based on the fundamental values for 
hydrogen, nitrogen, the halogens, silver, &c., as ascertained 
by the laborious and accurate determinations which have 
been made in various laboratories during recent years, and 
to which reference was made in preceding Reports, has 
now been completed and the Table submitted with the 
present Report embodies the results of the re-calculations. 
A number of atomic weights are shown to be slightly 
influenced by the adoption of the new values, but the 
changes thus introduced are, it must be admitted, less pro- 
found than was generally anticipated. Certain of the 
values still remain affected by errors far larger than those 
introduced by the selection of a particular fundamental 
value of the element with which comparison is made. — I 
am, Gentlemen, your obedient Servant, 

T. E. Thorpe. 

The Hon. Secretaries, The Chemical Society, 
Burlington House, London, W. 

Report of the International Committee on Atomic Weights, 
1909. 

Since the publication of our last Report, several im- 
portant memoirs upon atomic weights have appeared con- 
taining data of fundamental significance. They may be 
summarised as follows : — 

Hydrogen. — W. A. Noyes {yourn. Am. Chem. Soc, 

1907, xxix., 1718) has made complete syntheses of water 
in five series of determinations. The first series, however, 
was defective, and is therefore not published by the author. 
In mean, the four successful series give H = i"00787, as 
compared with Morley's figure, 100762. The general 
mean of these values, combined with all other trustworthy 
determinations, is i 00779. The rounded-off value, lOoS, 
is therefore retained in the table. 

Chlorine. — Noyes and Weber {jfoHrn. Am. Chem. Soc, 

1908, XXX., 13) have effected the synthesis of hydrochloric 
acid, weighing the hydrogen in palladium, the chlorine in 
potassium chloroplatinate, and also the hydrochloric acid 
produced by the union of the two elements. From the 
ratio H:C1, Cl = 35-458, when H = i"oo779. From the 
ratio H:HC1, Cl = 35-457. 

The same ratios have also been measured by Edgar 
(Proc. Roy. Soc, 1908, Ixxxi., A, 216), but by a different 
method. The hydrogen, as in former determinations, was 
weighed in palladium, but the chlorine was prepared by 
the electrolysis of fused silver chloride, and weighed in the 
liquid form. The hydrogen chloride was weighed directly 
in three experiments, and in two others after absorption in 
water. From the ratio H:C1, CI = 35'468. From the ratio 
H:HC1, Cl = 35-467. With Morley's value for H, the 
results are nearer CI - 35 46. Taking all the data together, 
the value CI = 35 46 seems to be as near the truth as can 
be positively asserted now. This includes the former work 
of Dixon and Edgar, and the density determinations by 
Guye and Gazarian. 



68 



International Committee on A tomic Weights 



Chemical News, 
Feb. 5, igog 



Sulphur (private communication from Prof. P. A. Guye). 
— From eighteen determinations of the density of hydrogen 
sulphide, Baume and Perrot deduce the value 8 = 32070. 
In an earlier investigation by Baume (Journ. Chim. Phys., 
1908, vi., 1), who determined the density of sulphur 
dioxide, he found lower values for S. (Baume also deter- 
mined the densities of methyl oxide and methyl chloride). 
The figure sa-o^, however, is in close agreement with the 
value obtained by Richards and Jones, when Ag = 107-88, 
and is doubtless very nearly true. 

L«a^.— Atomic weight determined by Baxter and Wilson 
[Proc. Amer. Acad., xliii., 365) from analyses of the 
chloride. WithAg = io7-93, Pb = 207-ig. With Ag - 107-88, 
Pb =207-10. This value is still much higher than that 
previously accepted. 

Cadmium. — Blum (Thesis, University of Pennsylvania, 
1908) has attempted to determine the atomic weight of 
cadmium by conversion of the oxide into the sulphide. 
The values obtained range from 112-50 to 112-88, and are 
admittedly of slight significance. 

Tellurium. — In an elaborate memoir upon the atomic 
weight of tellurium, Baker and Bennett (Trans., 1907, 
xci., 1849) give determinations by two new methods. By 
heating tellurium dioxide with sulphur in such a way that 
only sulphur dioxide could escape, the ratio TeOz to SO2 
was determined. From the mean of twenty-five deter- 
minations, Te = 127-609. By direction conversion of 
tellurium into the tetrabromide, the mean of eighteen 
determinations was Te = 127-601, when Br = 79-96. Re- 
ferred to Br = 7992, this becomes 127-54. Several 
analyses of tellurium tetrachloride, for which the details 
are not published, gave values for Te between 127-58 and 
127-64. On the basis of the modern values for Ag, CI, 
and Br, and with due regard to the earlier work of Pellini, 
Gutbier, Koethner, Norris, Scott Staudenmaier, and others, 
the rounded-off figure, Te = x27-5, seems to be fairly 
acceptable. 

Marckwald {Ber., 1907, xl., 4730), however, by careful 
dehydration of telluric acid, found values for Te ranging 
from 126-65 to 126-94. (For a criticism of Marckwald, see 
Baker, Chemical News, 1908, xcvii., 209). Six experi- 
ments were made, the mean of five, rejecting the lowest of 
all, being Te = 126-85. This falls below the atomic weight 
of iodine, and is therefore in harmony with the periodic 
classification. In view of the general agreement between 
other investigators in favour of a higher figure, Marckwald's 
work cannot be accepted without confirmation. The con- 
troversy over tellurium is evidently not ended. 

Rhodium. — Huttlinger {Diss., Erlangen, 1907), working 
in Gutbier's laboratory, made three reductions in hydrogen 
of rhodium pentamine chloride. His results, which seem 
to be preliminary in character, are practically identical 
with those obtained by Seubert and Kobbe, whose value 
for rhodium has been accepted since 1890. No change in 
this atomic weight is needed. 

Palladium. — Woernle (Sitzungsber. Phys. Med. Soz. 
Erlangen, xxxviii., 296) made seven analyses of pallados- 
amine chloride ; two by reductions in hydrogen, three 
electrolytically. Themean value obtained was Pd = 106-708, 
presumably computed with the old figures for N and CI. 

Haas {Diss., Erlangen, 1908), from similar reductions 
of palladosamine bromide, found Pd = 106-75, calculated 
with N = 14-037 and Br = 79-953. These determinations, 
like those of Krell, were made under the direction of Prof. 
Gutbier. The results obtained by Krell, Woernle, and 
Haas agree well together, and also with Amberg's deter- 
minations, and are probably quite accurate. Re-computed, 
with modern values for N and CI, Pd = 106-7 very nearly, 
with an uncertainty of not over 0-05. 

Lower values were found by Kemmerer (Thesis, Uni- 
versity of Pennsylvania, 1908), working under Prof. Edgar 
F. Smith. By reduction in hydrogen, palladosamine 
chloride gave Pd = 106-399 and 106-442 as the means of 
two series of observations. From palladosamine cyanide 
the value Pd = 106-458 was obtained. The mean of fifteen 
determinations, taken as one series, gave Pd = 106-434. 



The more concordant values cited above seem to be more 
trustworthy, at least so far as present evidence permits us 
to judge. Kemmerer's computations were made with 
N = 14-01 and CI = 35-473. 

Europium. — From analyses of the octahydrated sul- 
phate, Jantsch (Comptes Rendus, 1908, cxlvi., 473) finds 
Eu = 15203, when 8 = 32-06 and H = i*oo8. The round 
number 152 is retained in the table. This is probably the 
nearest significant figure. 

Erbium. — By repeated fractionation of erbium compounds 
Hofmann and Berger {Ber., 1908, xli., 308) have isolated 
an oxide of slightly higher molecular weight than that of the 
old erbia. To the new metal thus indicated they assign 
the name " neo-erbium," and by synthesis of the sulphate 
they find its probable atomic weight to be 167-43. The 
rounded-off figure 167-4 '^ given provisionally in the table, 
to stand until more complete data have been obtained. 

Ytterbium. — That the old ytterbium is a mixture of two 
elements has been proved by Urbain {Comptes Rendus, 
1907, cxlv., 759, November 4, 1907; see also Comptes 
Rendus, 1908, cxlvi., 406, and Chem. Zeit., 1908, xxxii., 
730), in Paris, and Auer von Welsbach, in Vienna 
(Monatsh., Feb., 1908, xxix., 181 ; read before the Vienna 
Academy, Dec, 1907), working almost simultaneously and 
independently. In his earlier paper, Urbain names the 
two elements " neoytterbium " and "lutecium," with approxi- 
mate atomic weights of 170 and 174 respectively. In his 
second memoir, Urbain gives atomic weights for a series 
of ytterbium fractionations, ranging from 170-6 to 174-02. 
Welsbach, whose work appeared later than Urbain's, 
names the two elements "aldebaranium," atomic weight 
172-90, and " cassiopeium," atomic weight I74-23. Since 
Urbain has clear priority, his nomenclature should be pre- 
ferred, but the atomic weights need to be more sharply 
determined. Incidentally, Urbain notes that the atomic 
weight of thulium is lower than 168-5. 

Columbium. — A concordant series of determinations 
made under the direction of Edgar F. Smith give columbium 
an atomic weight of 93-5 (Private communication ; the 
details are shortly to be published). This is lower than the 
value hitherto accepted. 

Radium. — Thorpe (Proc. Roy. Soc, 1908, Ixxx., A, 
298) has re-determined the atomic weight of radium by 
analyses of the chloride. In mean his determinations, 
calculated with Ag= 107-88 and CI =35-46, give Ra = 226-64. 
Thorpe, however, gives preference to the determinations 
by Mdme. Curie, who worked with larger quantities of 
material, regarding his own work as confirmatory. The 
re-calculated value is 226-4. 

In their Report for 1908, this Committee recognised the 
fact that a general revision of the atomic weight table was 
desirable, and such a revision has now been made. 
Modern investigations have shown that the fundamental 
values required modification, and through them many 
other atomic weights are affected, although the changes 
thus brought about are less important than they were 
generally supposed to be. Many atomic weights remain 
practically unaltered, and in few instances are the changes 
large, as a comparison of the new tnble with its pre- 
decessors will show. A careful scrutiny of all the evidence 
was, however, none the less necessary, and the table now 
offered gives the results thus obtained. 

The fundamental atomic weights, the standards of 
reference employed in the calculations, are as follows ; 
when O = 16 : — 



H .. 


I -008 


Br .. 


.. 79-916 


C .. 


1200 


Ag.. 


.. 107-880 


N ,. 


14-007 


K .. 


• • 39095 


CI .. 


.. 35-460 


S .. 


32 070 



The value for silver is possibly a trifle too low, by from 
three to five units in the third decimal place. A com- 
bination of the best measurements gives Ag = 107-883. In 
this case, and in others as well, the second place of 
decimals is given in the table, the third place being 



Chemical News, i 
Feb. 5, 1909 



Organic Derivatives of Silicon. 



69 



uncertain. Thus we have K, 39TO ; N, 14-01 ; Br, yg'ga ; 
&c. Only with hydrogen is the third place retained. 

In adjusting the other atomic weights, the determina- 
tions by Richards and his colleagues have generally been 
given preference. (An excellent summary of the Harvard 
work is given by Richards in yourn. Cliim. Phys., 1908, 
vi., 92). They are certainly entitled to the highest weight, 
but probably not to exclusive consideration. The work of 
Guye and his associates at Geneva, and the recent direct 
measurements of the chlorine-hydrogen ratio are also of very 
great importance. It is to work of this order that we must 
look for ultimate precision. Important investigations upon 
atomic weights are now being carried out in several 
laboratories, and our knowledge of these constants will 
doubtless become much more exact within the near future. 



(Signed) 



F. W. Clarke, 

W. OSTWALD, 

T. E. Thorpe, 

G. Urbain. 

International Atomic Weights, (1909). 
(O = 16). 

Aluminium Al 27*1 

Antimony Sb I20"i 

Argon A 39*9 

Arsenic As 75-0 

Barium Ba 137'37 

Bismuth Bi 208-0 

Boron B ii-o 

Bromine Br 79'92 

Cadmium Cd 112*40 

Caesium Cs i32-8i 

Calcium Ca 40-09 

Carbon C 12-00 

Cerium Ce 140-25 

Chlorine CI 35*46 

Chromium Cr 52- 1 

Cobalt Co 58-97 

Columbium Cb 93-5 

Copper Cu 63-57 

Dysprosium Dy 162-5 

Erbium Er 167-4 

Europium Eu 152-0 

Fluorine F 19-0 

Gadolinium Gd I57'3 

Gallium Ga 69-9 

Germanium Ge 72-5 

Glucinum Gl g-t 

Gold Au 197-2 

Helium He 4-0 

Hydrogen H 1-008 

Indium In 114-8 

Iodine I 126-92 

Iridium Ir 193-1 

Iron Fe 55-85 

Krypton Kr 81 -8 

Lanthanum La i39'o 

Lead Pb 207-10 

Lithium Li 7-00 

Lutecium Lu 174 

Magnesium Mg 24-32 

Manganese Mn 54'93 

Mercury Hg 200-0 

Molybdenum Mo 96-0 

Neodymium Nd i44'3 

Neon Ne 20 

Nickel Ni 58-68 

Nitrogen N 14-01 

Osmium Os 190-9 

Oxygen O i6-oo 

Palladium Pd 106-7 

Phosphorus P 31-0 

Platinum Pt i95'o 

Potassium K 39''° 

Praseodymium Pr l.to-6 



Radium Ra 

Rhodium Rh 

Rubidium Rb 

Ruthenium Ru 

Samarium Sa 

Scandium Sc 

Selenium Se 

Silicon Si 

Silver Ag 

Sodium Na 

Strontium Sr 

Sulphur S 

Tantalum Ta 

Tellurium Tc 

Terbium Tb 

Thallium Tl 

Thorium* Th 

Thulium Tm 

Tin Sn 

Titanium Ti 

Tungsten W 

Uranium . . , . , . . . U 

Vanadium V 

Xenon Xe 

Ytterbium (Neoytterbium) Yb 

Yttrium Y 

Zinc Zn 

Zirconium Zr 



226-4 
102-9 

85-45 
101-7 
150-4 
44-1 
79-1 
28-3 
107-88 
23-0* 
87-62 
32-07 
1810 
127-5 

304-0 
232-42 
168-5 
119-0 
48- ( 
184-0 

51-2 

128 

172 

89-0 

65*37 
90-6 



Of the following papers those marked * were read : — 

*i. "Organic Derivatives of Silicon. Part IX. Experi- 
ments on the Resolution of A\-Benzylethylpropy\sobutyl- 
silicanesulphonic Acid." By Frederic Stanley Kipping 
and Harold Davies. 

A\-Benzylethylpropyl\sobutyhilicane — 
SiEtPr(C4H9)-CH2Ph, 
a liquid boiling at 282 — 283°, has been prepared by treating 
benzylethylpropylsilicyl chloride (Kipping, Trans., 1907, 
xci., 717) with magnesium zsobufyl bromide ; when treated 
with chlorosulphonic acid, it gives a monosulphonic deriva- 
tive, which is isolated in the form of its /-menthylamine 
salt. 

\-Menthylamine d\-benzylethylpropyl'isobutylsilicanesnl- 
phonate, SiEtPr(C4H9)-CH2-C6H4-S03H,CioH2,N,2H20, 
separates from moist light petroleum in lustrous leaflets, 
and, when dehydrated, melts at 127 — 128°; it is very 
similar in its properties to the corresponding salts of 
benzylmethylethylpropylsilicanesulphonic acid (loc. cit.) 
and of benzylethyldipropylsilicanesulphonic acid (Marsden 
and Kipping, Trans., 1908, xciii., 205), although the latter 
is not a rfZ-compound. 

The strychnine, brucine, cinchonidine, quinine, and 
cinchonine salts of the dl-acid and the corresponding 
hydrogen alkaloidal salts of the last-named three bases 
have been prepared ; these eight compounds were 
systematically crystallised under various conditions, but 
in all cases, except in that of the cinchonine hydrogen 
salt, the melting- or decomposing-points and the specific 
rotations of the extreme fractions of a given salt were 
identical. The cinchonine hydrogen salt gave fractions 
having the same decomposing-points, but differing widely 
in specific rotation ; whether this difference is due to a 
resolution of the acid or not is still an open question. 

*2. " The Crystallisation of Externally Compensated 
Mixtures." By Frederic Stanley Kipping and William 
Jackson Pope. 

The recent publication of Ostromisslensky's paper {Ber., 
igoS, xli., 3035) on this subject affords an occasion for 
briefly recording the results of some work commenced in 
1898, but which has not been brought to a definite issue. 

On crystallising <//-sodium ammonium tartrate (prepared 
from purified racemic acid) from aqueous solutions of 
dextrose, and then re-crystallising the deposit, the product 
consisted, in nearly all cases, of the ff -tartrate, almost or 
entirely free from the /-salt (Proc, 1898, xiv., 113). 



70 



Women and the Chemical Society. 



I Crbhical News, 
I Feb. 5, 1909 



It is now shown that similar results are obtained in 
absence of dextrose even when the racemic acid, used in 
the preparation of the sodium ammonium salt, has been 
repeatedly crystallised from water. This preferential 
deposition of the rf-tartrate may be due to the seeding of 
the solutions by laboratory dust, or to the presence of a 
minute excess of the d-2ic\A in the racemic acid employed ; 
the results obtained on fractionally crystallising commercial 
racemic acid itself seem to show that the complete re- 
moval of extremely small quantities of dextrorotatory 
impurity is a very difficult matter. 

*3. " Formation of cyclohexanone Derivatives from 
Olefinic Compounds." By Siegfried Ruhemann. 

Although the esters of acetylenic acids form additive 
products with phenols, olefinic monocarboxylic esters or 
olefinic monoketones do not unite with sodium phenoxide. 
Condensation, however, takes place if the number of 
electronegative groups in an olefinic compound is in- 
creased. The additive compound of ethyl benzylidene- 
acetoacetate with sodium phenoxide at once condenses, 
thus — 

2CHPh(OPh)CHAc-C02Et = C26H2806 + 2C6H5-OH, 
yielding a compound, C26H28O6, which has twice the 
molecular formula of ethyl benzylideneacetoacetate. The 
substance is regarded as a c^c/ohexanone derivative, 

C02Et.CAc<^2phi^^?cS^>^0' ^^^ ^^'s constitu- 
tion is supported by a number of facts which the closer 
study of the reaction has furnished. 

Similar cjc/ohexanone derivatives have been obtained 
by the action of sodium phenoxide on benzylideneacetyl- 
acetone, CHPh:CAc2, and ethyl ethylideneacetoacetate, 
CHMeiCAc-COzEt. 

On the other hand, but in harmony with the above view 
of the formation of these c^cZohexanone compounds, neither 
ethyl benzylidenemalonate, CHPh:C(C02Et)2, nor ethyl 
benzylidenebenzoylacetate, CHPh:CBz-C02Et, condenses 
to cyclic compounds, although uniting with sodium phen- 
oxide. 

(To be continued). 



NOTICES OF BOOKS. 



Guide Pratique du Chimiste Metallurgiste et de VEssayeur. 
(" Practical Guide for the Metallurgical Chemist and 
Assayer "). By L. Campredon. Second Edition. 
Paris: Ch. Beranger. 1909. 
This work contains detailed descriptions of various 
methods of analysis employed in metallurgy and assaying, 
together with in most cases sufficient information on their 
applicability to enable the chemist to come to a judicious 
decision as to which one to adopt in particular cases. 
The number of methods desciibed, however, for a given 
constituent is often large, and occasionally a little more 
definite statements with regard to which one is most usually 
or satisfactorily employed might have been an advantage. 
The rare earths are included, and particular care has been 
taken to overlook no essential details of manipulation and 
to make the book a thoroughly practical laboratory guide ; 
indeed, in some respects the author has carried his en- 
deavours after completeness rather far, and there is some 
matter dealing with quite elementary processes and ap- 
paratus which might have been omitted without in any 
way diminishing the usefulness of the book. 



Feste Losungen und Isomorphismus. (" Solid Solutions 

and Isomorphism "). By Dr. Giuseppi Bruni. Leipzig: 

Akademische Verlagsgesellschaft. 1908. 

One of the easiest ways of getting a general idea of a 

branch of any scientific subject is to read a good lecture in 



which in nearly all cases the matter is stated more simply 
and also more graphically than in an article. The truth 
of this general statement is well illustrated by this book, 
which is a reproduction with some extensions of a lecture 
delivered by Prof. Bruni before the Chemical Society at 
Breslau. The text is divided into numerous very short 
chapters, each one discussing some single point ; many 
summaries are given, and as little mathematics as possible 
is introduced. The text is thus easy to follow, and, more- 
over, it gives a survey of the whole subject, details being 
avoided as far as possible. The lecture was divided into 
two parts, the first dealing with the nature of solid solu- 
tions, their methods of formation and most important 
properties, and the second giving a discussion of the 
disputed question of isomorphism in the light of recent 
advances. The relation between crystalline form and 
chemical constitution is well treated, and an ingenious 
table shows at a glance the behaviour of the elements, 
especially the metals, when they separate from mixed 
binary melts. 



CORRESPONDENCE. 



WOMEN AND THE FELLOWSHIP OF THE 
CHEMICAL SOCIETY. 

To the Editor of the Chemical News. 

Sir, — It has come to our notice that a report has been 
widely circulated and credited to the effect that the move- 
ment in favour of the admission of women to the Fellowship 
of the Chemical Society is directly connected with the 
present agitation for the political enfranchisement of women. 
We, the undersigned women (actively engaged in chemical 
teaching and research), beg to ask for the hospitality of 
your columns in order to deny any such connection. The 
following facts, we venture to think, should prove the in- 
dependence of the two movements : — 

1. Five years ago when some of us petitioned the 
Council of the Chemical Society to admit us to the Fellow- 
ship, the agitation in favour of "Woman Suffrage " was 
not prominently before the public. 

2. The petition recently presented to the Council 
originated within the Chemical Society itself, and was 
signed exclusively by Fellows of the Society. 

Moreover, we, as a body, have no knowledge of the 
political opinions and aspirations held by individual 
members ; any such knowledge we should consider to be 
quite irrelevant, since the only link which unites us is a 
common interest in the science of chemistry. We are 
glad to take this opportunity of recording our thanks to 
those Fellows of the Chemical Society who have expressed 
themselves in favour of admitting women to the Fellowship 
of the Society. — We are, &c., 

(Signed) 

Heather H. Beveridge, B.Sc, Carnegie Research 

Scholar, Univ. of Edinburgh. 
Mary Boyle, B.Sc, Lecturer and Demonstrator in 

Chemistry, Royal HoUoway College. 
K. A. Burke, B.Sc, Assistant in Department of 

Chemistry, University College, London. 
Frances Chick, B.Sc. 
Louisa Cleaverley. 
Margaret D. Dougal, Indexerof the Publications of 

the Chemical Society. 
C. DE B. Evans. D.Sc, Lecturer in Chemistry, London 

School of Medicine for Women. 
E. Eleanor Field, M.A., Senior Staff Lecturer in 

Chemistry, Royal Holloway College. 
Emily L. B. Forster, Private Assistant to Prof. 

Huntington, King's College, London. 



Chemical News, I 
Feb. 5, igog i 



Chemical Notices from Foreign Sources, 



71 



Ida Freund, Natural Science Tripos, Cambridge, 
Staff Lecturer in Chemistry, Newnham College. 

Maud Gazdar, Demonstrator in Department of 
Chemistry, University College, London. 

Hilda J. Hartle, B.Sc, Lecturer in Chemistry, 
Homerton Training College, Cambridge. 

E. M. HiCKMANS, M.Sc. 

Annie Homer, B.A., Fellow and Associate of 
Newnham College, Cambridge. 

Ida F. Homfray, B.Sc. 

E. S. Hooper, B.Sc, F.I.C, Assistant Lecturer and 
Demonstrator, Portsmouth Municipal College. 

Edith Humphrey, B.Sc, Ph.D., Chemist to A. 
Sanderson and Sons. 

Zelda Kahan, B.Sc. 

NoRAH E. Laycock, B.Sc, Demonstrator in Chemistry, 
London School of Medicine for Women. 

Elison a. Macadam, F.I.C, Private Assistant to 
Prof. Huntington, King's College, London. 

Effie G. Marsden. 

Margaret Mckillop, M.A., Lecturer in Chemistry, 
King's College, Women's Department. 

Agnes M. Moodie, M.A., B.Sc. 

Nora Renouf, late Salter's Research Fellow, School 
of Pharmacy. 

Ida Smedley, D.Sc, Assistant Lecturer and Demon- 
strator in Chemistry, Victoria University, Man- 
chester. 

Alice E. Smith, B.Sc, Assistant Lecturer and Senior 
Demonstrator in Chemistry, University College of 
North Wales, Bangor. 

MiLLicENT Taylor, B.Sc, Lecturer in Chemistry, 
Ladies' College, Cheltenham. 

M. Beatrice Thomas, M.A., Lecturer in Chemistry, 
Girton College, Cambridge. 

M. A. Whiteley, D.Sc, A.R.C.S., Demonstrator in 
Organic Chemistry, Royal College of Science, 
London. 

Sibyl T. Widdows, B.Sc, Head of Practical 
Chemistry Department, London School of Medi- 
cine for Women. 

Katharine I. Williams. 



Since the above was written the following letter has 
been sent to the signatories of the original petition : — 

London, January 30, igog. 

Dear Sir, — At a meeting of representative women 
chemists held on the 8th inst., a hearty vote of thanks was 
accorded to the 312 Fellows of the Chemical Society who 
presented the petition to the Council praying for the 
admission of women to the Fellowship. At the same 
meeting it was unanimously decided that it is not advisable 
for women to take advantage of the new regulation adopted 
by the Council whereby women are permitted to become 
" Subscribers." In conveying to you, as one of the signa- 
tories of the petition, our thanks for your efforts to obtain 
for us recognition of our claim to be admitted to the 
Fellowship, we wish to state that the above decision was 
reached only after careful consideration of its bearing on 
the fundamental question on which the petition and 
referendum were based. We are of opinion that by be- 
coming Subscribers to the Chemical Society we should 
prejudice unfavourably the case for granting to women the 
Fellowship of the Society. — We are, &c., 

(Signed as above). 



Impersonation. — A Warning. — Consulting and ana- 
lytical chemists and others are again warned against 
receiving a tall seedy-looking man, who, on the plea of 
ill-health, solicits pecuniary or other assistance by im- 
personating a certain Fellow of the Institute of Chemistry 
in practice at Warrington. 



CHEMICAL NOTICES FROM 
SOURCES. 



FOREIGN 



^^OTB. — All degrees of temperature are Centigrade anleti otherwiaa 
expressitd. 

Comptes Rendus Hebdomadaires des Seances de VAcademie 

des Sciences. Vol. cxlvii., No. 26, December 28, 1908. 

Law of the Optimum of Cathode Phosphorescence 
of Binary Systems. — G. Urbain. — The following are the 
general results of the author's experimental work on 
cathode phosphorescence : — i. As Lecoq de Boisbaudran 
has maintained, pure substances exhibit no appreciable 
phosphorescence ; bright phosphorescence is always due 
to the mixture of at least two substances. 2. In a phos- 
phorescent binary system the optimum of phosphorescence 
always corresponds to small quantities of phosphorogen. 
3. The optimum law is general, applying to ordinary sub- 
stances and to the rare earths. 4. The coloration of the 
phosphorescence and its spectrum may vary with the 
degree of dilution of the phosphorogen. 5. With prepara- 
tions made from pure substances all the spectral variations 
observed in the intermediate mixtures which the fractiona- 
tion of the rare earths gives can be reproduced. Thus 
these variations do not prove that the fractionation has 
split a simple substance into several constituents. The 
optimum law may be enunciated as follows : — In every 
phosphorescent binary system in which the relative pro- 
portions of phosphorogen and diluent are varied each band 
of phosphorescence passes through an optimum, and the 
optima of different bands do not necessarily coincide, 
although they always correspond to relatively feeble pro- 
portions of phosphorogen. 

Reduction of Uranyl Chloride. — Oechsnerde Coninck. 
— Uranyl chloride is readily reduced at an incipient red 
heat by hydrogen, UO2CI2+2H = U02 + 2HC1. This 
process the author has applied to determine the atomic 
weight of chlorine, but the results obtained did not agree 
very well ; the mean value was 3536. Uranyl chloride, 
moreover, has a tendency to dissociate into chlorine and a 
subchloride, and it reacts very readily with the water 
vapour of the air, giving hydrochloric acid and uranium 
trioxide, UO2CI2 . H2O = U03-I-2HC1. 

Preparation of Ether Salts of the Cyclic Series.— 
A. Behal. — When a mixture of benzyl chloride and acetic 
acid is heated, hydrochloric acid is set free and an ether 
salt of the cyclic radicle is formed. The author has shown 
that the hydrogen of the acid OH group is eliminated with 
the chlorine of the molecule of benzyl chloride, and benzyl 
acetate is thus formed. Many halogen salts of the metals 
or compounds of the metals which are decomposed by the 
hydracids (oxides, carbonates, organic salts) promote the 
course of the reaction. Some of these substances induce 
condensation and some do not. 

Preparation and Properties ot e-Gluco-heptite. — 
L. H. Philippe. — By reducing /i-gluco-heptonic lactone 
with sodium amalgam at - 2° and eliminating the sodium 
sulphate formed by means of alcohol, a colourless syrup is 
obtained containing j8-heptose and sodium heptonate. 
This syrup the author dissolved in water and treated again 
with sodium amalgam, shaking thoroughly. After sepa- 
rating the sodium sulphate and concentrating the solution 
the heptite may be isolated by dissolving in alcohol at 95°, 
in which sodium heptonate is insoluble. The composition 
of ^-gluco-heptite corresponds to the formula C7H16O7, 
the constitutional formula being — 



CH2(0H)- 



OH OH H OH H 



.C C — C— C— C— CH2(0H) 

H H OH H OH. 

It crystallises in little rectangular tablets which are hard 
and not hygrometric. Its solubility in cold water is 50 per 



1^ 



Meetings for the Week. 



I Chemical News, 
t Feb. 5, 1909 



cent and increases rapidly with the temperature. It is 
nearly insoluble in cold alcohol. It iuses at 130° to 131" 
like its a-isomer, but differs from the latter in optical 
activity, being feebly dextrorotatory in aqueous solution. 
It becomes laevo-rotatory in presence of borax. 

Vol. cxlviii., No. i, January 4, igog. 

Density of Methane. Atomic Weight of Carbon. 
— Georges Baume and F. Louis Perrot. — Accurate deter- 
minations of the density of methane show that the mean 
value of the weight of a normal litre is 07168 grm. From 
the molecular weight thus obtained the value of the atomic 
weight of carbon can be calculated. The mean value is 
found to be 12004. Methane solidifies easily in liquid 
air. It fuses at - 184° to a colourless mobile liquid, the 
density of which varies from 0477 to 0406. 

Hydrogen Silicides. — P. Lebeau. — The author has 
treated a large quantity of magnesium silicide with hydro- 
chloric acid and condensed the hydrogen silicides formed 
in liquid air. When the solidified products are allowed to 
assume the temperature of the air a gaseous product is 
obtained and a colourless liquid is left behind. By cooling 
the gaseous product in liquid air and slowly fractionating, 
SiaHe is obtained and the liquid residue appears to be 
Si2H4, which is very inflammable in oxygen. 



MISCELLANEOUS. 

Reduction of Salicylic Acid to Salicylic Aldehyde. 
— Hugo Weil. — Sodium salicylate is very readily reduced 
by sodium amalgam in aqueous solution at the ordinary 
temperature, if boric acid is also present, the product of 
the reaction being salicylic aldehyde. The yield is greater 
if an aromatic amine (especially />-toluidine) is added to the 
liquid. A difficultly soluble Schiff's base is thus formed, 
and up to 60 per cent of the theoretical yield of aldehyde 
can be obtained. The residue is a paste, probably a con- 
densation product of salicylic alcohol. — Ber., xli.. No. 17. 



MEETINGS FOR THE WEEK. 

Tuesday, gth. — Royal Institution, 3. "Architectural and Sculptural 
Antiquities of India," by Prof. A. A. Macdonell. 

Faraday Society, 8. " Applications of Electrolytic 

Chlorine to Sewage Purification and Deodorisation 
by the ' Oxychlorides ' Process," by S. Rideal. " New 
Electrical Hardening Furnace," by E. Sabersky. 
Wednesday, loth. — Royal Society of Arts, 8. "Bosnia and Herze- 
govina," by A. R. Colquhoun. 
Thursday, ixth. — Royal Institution, 3. "Revival of Modern Drama," 

by William Archer, M.A. 
Friday, i2th. — Royal Institution, g. "The Electrical Properties of 
Hame," by Prof. H. A. Wilson, F.R.S., &c. 

Physical, 8, (Annual General Meeting). 

Saturday, 13th. -Royal Institution, 3. " Mendelssohn," Sir Alexander 
C. Mackenzie. (With the kind assistance of the 
Hans Wessely Quartette). 



PRICE ONE SHILLING Net. Post free, Is. Id. 

DIAMONDS. 

A Lecture delivered before the British Associatioa 
at Kimberley. 

By SIR WILLIAM CROOKES, 

Hon. D.Sc. (Oxford, Dublin, and Oape of Good Hope), F.R.S. 

CHEMICAL NEWS OFFICE, 
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ON 

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FOURTH EDITION, ENTIRELY RE-WRITTEN AND 
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CHEMICAL TECHNOLOGY 

ANALYSIS OF OILS, FATS, AND WAXES. 

BY 

Dr. J. LEWKOWITSCH, M.A., F.LC, F.C.S., 

Consulting and Analytical Chemist and Chemical Engineer ; 
Examiner in Soap Manufacture and in Fats and Oils, including 
Candle Manufacture, to the City and Guilds of London Insti- 
tute. With 88 Illustrations and numerous Tables. In Three 
Volumes. Medium 8vo, gilt tops. [/« the Pie.s. 

NATUHE. — "The standard English book of reference on the 

subject." 

Laboratory Companion to 

Fats and Oils Industries. By J. 

LEWKOWITSCH, M.A., F.LC. 8vo. 65. net. 

A Dictionary of Chemical 

Solubilities, Inorganic. By A. M. 
COMEY, Ph.D. Demy 8vo. 15s. net. 

An Experimental Study 

of Gases. By Prof. M. W. TRAYERS. 

8vo. 105. net. 

Practical Chemistry. By 

R. ABEGG and W. HERZ. Translated by H. T. 
CALVERT, B-.Sc. Crown 8vo. 65. 

A System of Volumetric 

Analysis. ByDr.EMIL FLEISCHER. Trans- 
lated, with additions, by M. M. P. MUIR, 
F.R.S. E. Crown 8vo. 7s. 6d. 

Practical Methods of Or- 
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MANN, Ph.D. Translated by W. B. SHOBER. 
Crown 8vo. 8s. 6d. 

Blowpipe Analysis. By 

FREDERICK HUTTON GETMAN. Globe 8vo. 
2S. 6d. net. 

Methods of Gas Analysis. 

By Dr. WALTHER HEMPEL. Translated by 
L. M. DENNIS. Crown 8vo. 10s. net. 

Blowpipe Analysis. By 

J. LANDAUER. Third Edition. Translated by 
J. TAYLOR. Globe 8vo. 4s. 6d. 



MACMILLAN & CO., Ltd., LONDON. 



Chemical' News, 
Feb. 12 1909 ' 



Action of Permdni^anate on Ferrous Salts. 



73 



THE CHE IVIICAL NEWS. 



Vol XCIX., No. 2568. 



THE ACTION OF PERMANGANATE 

ON FERROUS SALTS IN PRESENCE OF 

HYDROCHLORIC ACID. 

By W. COLET BIRCH, B.A., A.I.C. 

(Concluded from p. 63). 

III. 

The gas evolved during the progress of some of the 
titrations resembled, as has been noted above, chlorine 
monoxide rather than chlorine. 

In the event of the discrepancies being due to the 
irregular reaction of either of these two gases with ferrous 
salts, it was thought well to test their reaction under 
conditions similar to those which occur when a titration 
with permanganate is being carried out. 

A solution of chlorine in water was prepared of such a 
strength that 22'5i cc. were equivalent in their iodine 
liberating power to i cc. of permanganate. 

Twenty cc. of a ferrous solution were mixed with a little 
dilute sulphuric acid, 10 cc. of chlorine water were added, 
and the solution made up to 100 cc. For the completion 
of the oxidation i3"04 cc. permanganate were required. 

The amount of permanganate for the complete oxidation 
of 20 cc. ferrous solution was i3'40 cc. 

The actual difference found is o'36cc.,that calculated 
is o'44 cc. 

In another titration in which 50 cc. of chlorine water 
were used, 11-22 cc. permanganate were required for com- 
pletion of the oxidation. 

The difference is 2- 18 cc, and the calculated difference 
2'22 cc. 

Similar titrations were carried out with freshly prepared 
and standardised hypochlorous acid solution. 

Twenty cc. of the ferrous solution, when mixed with 
5 cc. hypochlorous acid, required 8-91, 8-89, 8-91 cc. per- 
manganate ; mean, 8'90 cc. 

The amount of permanganate to oxidise 20 cc. ferrous 
solution was i2'2o cc. 

The difference is 3"30 cc, and the calculated difference 
3-39 cc. 

The reaction therefore between ferrous sulphate and 
both chlorine and hypochlorous acid is regular. 

If the discrepancies in the process are due merely to the 
liberation of chlorine, the amount of chlorine evolved 
should be equivalent in oxidising power to the excess of 
permanganate required in the first titration. To ascertain 
if such is the case, a titration was carried out in a closed 
flask through the cork of which the nozzle of the burette 
passed. 

The permanganate required for 20 cc. of solution was 
13-19 cc, the true value being 13-11 cc. The burette was 
replaced by a tube dipping into the liquid in the flask, and 
the flask attached to two U-tubes containing KI solution. 

A current of air was aspirated through the apparatus 
for two hours, and the liberated iodine was titrated with 
thiosulphate ; 2-67 cc. were required. 

If all the available oxygen contained in the excess of 
permanganate had been used to oxidise the hydrochloric 
acid with the consequent liberation of iodine, 7-43 cc. of 
the thiosulphate solution would have been required instead 
of the 2-67 cc. found. 

This points to the occurrence of another action besides 
that by whiph chlorine is liberated. This other action is 
probably responsible for the brown compound which is apt 
to obscure the end-point. 

The brown solution obtained looks very like that pro. 



duced when Mn02, Mn203, or Mn304 is dissolved in con- 
concentrated hydrochloric acid and the solution kept cold. 

Pickering (yourn. Chem. Soc, 1879, i.,654) showed that 
this solution contains MnCl3, which, however, he did not 
isolate. 

To investigate the reaction between HCl and KMnO^ 
solution, both alone and when mixed with other salts, the 
following experiments were carried out : — 

Mixtures of permanganate and hydrochloric acid were 
made, and air was then aspirated through the solution, the 
evolved gases being led into two U-tubes containing 
potassium iodide. The liberated iodine was titrated with 
thiosulphate solution. 

Table VI. contains the results obtained. By comparing 
rows I., III., and IV. of Column 6 it is evident that MgS04 
and Na2S04 have no effect on the reaction, while in 
row II,, in which MnS04 was present, there was an 
almost complete suppression of the chlorine. 

In the case of row V. when ammonium sulphate was 
present the reaction seems to be quite anomalous, chlorine 
capable of liberating iodine, and also probably of oxidising 
feirous salts, disappearing. 

The addition of this salt before titrating would conse- 
quently be expected to have a distinctly bad effect. Such 
an effect is indeed noticeable, as will be seen on referring 
to Table IV. 

Supposing that the brown solution contains the com- 
pound MnClj investigated by Pickering, the reaction could 
be represented as follows : — 

Mn207 + i4HCl = 2MnCl3 f 7H20-f-4Cl2. 

If this action takes place one-fifth of the total available 
chlorine would be left behind as MnCl3, and four-fifths 
carried over into the potassium iodide. 

The numbers in Column 7 of Series III. and IV should, 
if this view is correct, be one-fifth of the numbers in 
Column 6. In row III. this is approximately the case, 
while in row IV. multiplication by six gives a better result. 

The agreement is perhaps as near as can be expected 
when the unstable nature of MnCl3, and the possible 
existence of a less stable MnCl4 (Nickles, Ann. Chitn. 
Phys., [4], v., 161), is taken into account. 

IV. 

Rice {jfourn. Chem. Soc, 1898) obtained crystalline 
double salts of KCl and NH4CI with MnCl3 by adding 
saturated solutions of these salts to the cooled brown solu- 
tion obtained by the action of hydrochloric acid on any of 
the higher oxides of manganese. It seemed advisable to 
try and obtain similar salts from the brown solution pro- 
duced by the action of permanganate on hydrochloric acid. 
Dry hydrochloric acid was passed into a saturated solution 
of potassium permanganate and potassium chloride cooled 
in a freezing mixture of ice and salt. 

Very little chlorine was evolved, the mixture turned 
deep brown, and at first a large quantity of potassium 
chloride was precipitated. This was separated, and the 
solution re-saturated with hydrochloric acid ; a black pre- 
cipitate was formed, which was filtered off, washed with 
concentrated hydrochloric acid, and dried in a calcium 
chloride dessicator containing some solid potash. 

A black crystalline powder resulted which was decom- 
posed by water, giving a copious precipitate of hydrated 
oxides of manganese and a smell of chlorine. It dissolved 
in strong hydrochloric acid, giving a deep reddish brown 
solution capable of liberating iodine from potassium 
iodide, and generally behaving in the same way as the 
brown solutions met with in the course of the above 
titrations. 

The salt gave on analysis 16-09 per cent Mn, 25-78 per 
cent K, and 10-33 P^'' *^^"' ^'« capable of liberating iodine. 

The theoretical numbers for MnCl3.2KCl.H2O are : — Mn, 
16-74 ; K, 23-75 ; available CI, 10-80. 

The excess of potassium found is 2-03 per cent, and this 
calculated as KCl, probably present as impurity, is 3-87 
per cent. 



74 



Osmotic Pressure of Concentrated Solutions, 



Chemical News, 
1 Feb. 12, 1909 











Table VI. 












I. 


2. 


3- 


4- 


5- 


6. 


7- 


8. 


9- 




HCl 


KMn04 








Thio. for 


Thio. for iodine 




Thio. for 




solution 


solution 




Water 


Time for 


iodine 


liberated on 


Sum of 


iodine liberated 




(293-9 grms. 


(4'072 grms. 


Salt added. 


added. 


which air 


liberated in 


adding KI to 


6 and 7. 


by 10 cc. 




per litre). 


per litre). 






was passed. 


U -tubes. 


solution in flask. 




KMn04. 




Cc. 


Cc. 




Cc. 


Hours. 


Cc. 


Cc. 




Cc. 


I. 


25 


10 


— 


65 


2 


38-13 


— 


— 


46-32 


II. 


25 


10 


25 CC. MnS04 
(150 grms. per litre) 


40 


2i 


0-49 


— 


— 


46-32 


III. 


25 


10 


25 cc. MgS04 
(246 grms. per litre) 


40 


2 


38-14 


7-80 


45-94 


46-32 


IV. 


25 


10 


25 cc. Na2S04 
(142 grms. per litre) 


40 


2 


38-85 


6-13 


44-98 


46-32 


V. 


25 


10 


25 cc. (NH4)2S04 
(132 grms. per litre) 


40 


2 


2-14 


i-i6 


3-30 


46-32 



On re-calculating the percentages, allowing for the 
presence of 387 per cent of KCl, there are obtained : — 
Mn, 16-74 ; and CI, 10-74. The salt analysed was therefore 
the same as that obtained by Rice mixed with some 
potassium chloride. 

Conclusions. 

It seems obvious from the above that the brown solu- 
tions repeatedly met with are due to the presence of the 
compound MnCl3. This accounts for the irregularities 
attendant on Marguerite's process when applied in presence 
of hydrochloric acid. 

Since the brown colour is discharged on adding a ferrous 
salt, and since chlorine reacts regularly with the same, it is 
to be concluded that the irregular numbers of Table I. are 
due to the loss of a varying amount of chlorine from the 
solution, combined with the greater or less degree to which 
the action between HCl and permanganate has progressed. 

The suppression of the chlorine evolution by the addition 
of excess of manganous salt is also explained, since Rice 
{yonrn. Chetn. Soc, 1898) has shown that MnCla and free 
chlorine when sealed up in a tube react slowly to give 
MnCl3, and, further, Pickering {jfourn. Chetn. Soc, 1879, 
XXXV., [i] , 654) showed that the amount of manganic salt 
produced when MnOa dissolves in HCl is increased by the 
presence of MnCb, the increase being presumably due to 
the combination of the extra atom of chlorine with the 
MnCU present. 

This fact further explains the fair agreement of the 
numbers in Table V. 

Erratum. — P. 61, Table, col. 8, line 3 from bottom, 
for " - o-og " read " + 0-09." 
King's College, Cambridge. 



THE OSMOTIC PRESSURE OF 

CONCENTRATED SOLUTIONS, AND THE LAWS 

OF THE PERFECT SOLUTION.* 

By GILBERT NEWTON LEWIS. 
(Concluded from p. 64). 

Note I. 
If a solution and the pure solvent are separated by a 
semipermeable membrane the solvent will flow through 
the membrane into the solution, where its escaping ten- 
dency is less. The only way of preventing this flow is to 
make the escaping tendency of the solvent the same on 
both sides of the membrane. There are two simple ways 
of accomplishing this, (i) to increase the pressure on the 
solution until the escaping tendency of the solvent in the 
solution is raised to equal that of the solvent in the pure 
state ; {2) to diminish the pressure on the pure solvent 
* From the Journal of the American Chemical Society, xxx., No. 5. 



until its escaping tendency is lowered to equal that of the 
solvent in the solution. 

The osmotic pressure may therefore be defined in two 
ways, (i) as usually defined it is the increase in the pres- 
sure on the solution necessary to bring the latter into 
equilibrium with the solvent ; (2) Noyes {Zeit. Phys. 
Chetn., 1900, XXXV., 707), however, prefers to define the 
osmotic pressure as the diminution in the pressure on the 
solvent necessary to bring it into equilibrium with the 
solution. Neither of these definitions is entirely free from 
objections, but since the second one permits a much 
simpler mathematical treatment than the first, it has been 
adopted throughout this paper. The osmotic pressures 
defined in these two ways differ only when there is a total 
change of volume when a small quantity of solvent is 
added to a solution. There is no such volume change in 
the case of sugar and glucose as shown by the experiments 
of Morse and Frazer and of Ewan. We have been justified, 
therefore, in applying our equations, which involve the 
osmotic pressure according to the second definition, to the 
results of Morse and Frazer, who worked with the osmotic 
pressure of the first definition. 

Note 2. 
The exact equation connecting osmotic pressure and 
freezing-point may be found as follows : — Let us consider 
an aqueous solution in equilibrium with ice at the tem 
perature T and the pressure p, and also in equilibrium 
with these, through a semipermeable membrane, pure 
water at the same temperature and at the pressure p —Tl, 
n obviously being the osmotic pressure. Now if the tem- 
perature changes by dT and the pressure on the solut/on 
and ice remains equal to P, that on the water must be 
changed in order to maintain equilibrium. The necessary 
change in pressure we will call dXl. Since the water and 
ice are in equilibrium at the beginning, the activity | of 
the water and the activity |' of the ice must be equal, and 
these, moreover, must remain constant as the temperature 
changes. Hence — 

1 = 1' 
and — 

di = d^' 
or — 

dln^ = dlni;. 

Now the change in the activity of the ice is due only to 
the change of temperature, that is — 



dlni'^(^^J)dT, 



but the activity of the water is changed both by the change 
in temperature and the change in pressure, that is — 



.,„=(|^).T.(8-i).„. 



Chemical News, 
Feb. 12, 1909 ( 



Osmotic Pressure of Concentrated Solutions. 



Equating the last members of these two equations, we 
have — 

Now, substituting for the partial differentials their values 
from the fundamental thermodynamic equations (Lewis, 
loc. cit., Equations V. and VIII. ; it is, of course, to be 
noted that, by definition, n is a negative pressure), and 
combining the first two terms gives — 

dn ^ -L . 
dT vT ' 

where L is the heat absorbed in the fusion of i grm. of 
ice and v is the volume of i grm. of water. Foi T we 
may substitute 273-1 -A, where A is the lowering of the 
freezing-point below the centigrade zero, whence — 

dn L 

dA w(273'i — A) 

In order to integrate this equation, L and v must be 
known as functions of A. According to a well-known 
principle the change of L with A is given by the equation — 

L = Lo - CA ; 

where Lo is the heat of fusion at 0° C. and C is the 
difference between the specific heats of water and ice. 
According to the best available data, C is about 0-5 if our 
unit of energy is the calorie, or 21 if our unit of energy is 
the cc.-atmos. The value of Lo obtained in the very 
accurate experiments of Smith was 334'2 joules {Phys. 
Rev., 1903, xvii., 231), assuming the electromotive force 
of the Clark cell to be i'434 V at 15^. Since this value 
entered twice into the calculation of Smith, if we adopt 
for the Clark cell the value now accepted of 1*433 V, the 
value of Lo must be lowered by 2 parts in 1434 and be- 
comes 333-7 joules, or 3294 cc.-atmos. (Guttman, yo2<m. 
Phys. Chetn., 1907, xi., 279, has made a similar re-calcu- 
lation of Smith's value, but applied only one-half of the 
correction applied above). 

We may therefore write — 

L = 32g4 — 21A. 
Strictly speaking, L is a function of the pressure also, but 
the pressure effect may easily be shown to be too small to 
be considered in the present calculation. 

The volume of a grm. of water also depends upon both 
temperature and pressure. We shall see that i degree 
lowering of the freezing-point corresponds to about 12 
atmos. change in the osmotic pressure. Hence from the 
known coefficients of thermal expansion and compressi- 
bility we find that the value of v may be expressed very 
closely by the linear equation, — 

v = i -000 + 0-0008 A. 

Substituting now in the above equation the values of L 
and V, and performing the multiplications and divisions 

indicated, we obtain _ as a series function of A, namely, — 



75 



IdA 



dA 
= 1206 0-0414 A -0-00009 A '^ + 



Except for very high values of A and A* term and all the 
higher terms are negligible. Dropping these terms, there- 
fore, and integrating, we have — 

n 1206 A - 0-2I A*. 

By this equation the osmotic pressure corresponding to 
any freezing-point lowering may be calculated immediately, 
and, if the experimental data used are as accurate as they 
appear, the error of the calculation can hardly exceed a 
few tenths of a per cent even at osmotic pressures of 
several hundred atmospheres. 

Ncfe 3. 
The connection between the osmotic pressure and the 
vapour pressure of the solvent from a given solution is 
obtained as follows : — From the fundamental thernrjo ■ 



dynamic equation for the change of the activity of a 
substance with the pressure (Lewis, loc. cit., Equation V.), 
we have — 

din ^ -V . 

dn RT • 

where V is the molecular volume and | is the activity of 
the pure solvent. When the vapour of the solvent behaves 
like a perfect gas whose pressure is p we may write — 

dln^ = dlnp. 
Hence, in such a case, — 

dlnp ^ -V 

dn ~rY" 

V may be regarded as constant for small values of n but 
at high pressures we must consider the compressibility of 
the solvent. If the coefficient of compressibility of the 
solvent is denoted by a, and the volume when the osmotic 
pressure is zero by Vo — 

V = Vo(i-on). 
Substituting this value of V in the above equation and 
integrating, we have — 

n-i«n^ = ^1 inh.; 
2 Vo ^ ' 

where {>o is the vapour pressure of the pure solvent, p that 
of the solvent in the solution of osmotic pressure n. This 
equation is derived for the case that the vapour of the 
solvent obeys Boyle's law. In any other case a more 
complicated formula must be used. 

Summary. 

The simple laws of the infinitely dilute solution become 
mutually incompatible in solutions of finite concentration. 
It is therefore necessary to choose one law to serve as a 
criterion of the perfect solution. The only law of dilute 
solutions which ever holds in concentrated solutions is 
the law of Raoult. This law is stated in a slightly modified 
form, and a perfect solution is defined as one which obeys 
this law. A number of solutions are mentioned which 
behave as perfect solutions over the whole range of con- 
centrations, from o per cent to 100 per cent solute. 

The indirect methods of determining osmotic pressure 
are discussed and an exact relation between the osmotic 
pressure and the freezing-point lowering of an aqueous 
solution is obtained. It is also pointed out that the 
osmotic pressure at one temperature may be obtained from 
that at any other when the heat of dilution is known. 

Adopting Raoult's law in its modified form as the 
characteristic law of the perfect solution, it is possible 
with the aid of thermodynamics alone to obtain an equation 
connecting the osmotic pressure and concentration of a 
perfect solution. The equation thus obtained permits the 
exact calculation of osmotic pressures in perfect solutions, 
up to 1000 atmos. In comparatively dilute solutions the 
pressures thus obtained are substantially identical with 
those given by the equation of van 't Hoff, as modified by 
Morse and Frazer, but at high concentrations the divergence 
between the two equations is very great. 

An exact form is obtained for the mass law in concen- 
trated perfect solutions. 



Society of Public Analysts. — At the Annual General 
Meeting of the Society on February 3rd, the following 
Officers and Council were elected to serve during the year 
1909 : — President — R. R. Tatlock. Past-Presidents (limited 
by the Society's Articles of Association to eight in number) 
— M. A. Adams, Edward J. Bevan, Bernard Dyer, Thomas 
Fairley, W. W. Fisher, Otto Hehner, J. Augustus Voelcker. 
Vice-Presidents — Bertram Blount, Cecil H. Cribb, H. 
Droop Richmond. Hon. Treasurer — E. W. Voelcker. 
Hon. Secretaries — Alfred Chaston Chapman, P. A. Ellis 
Richards. Other Members of Council — W. J. A. Butter- 
field, H. C. H. Candy, Harold G. Colman, Arthur E. 
Ekins, John Golding, A. R. Ling, L. Myddelton Nash, 
James Nimmo, Frederic W. Richardson, F. G. Ruddock, 
G- E. Scott-Smith, Clarence A. Seyler. 



76 



A tomic Weights of Nitrogen and Silver, 



(Chemical News, 
Feb. 12, 1909 



SOME PROPERTIES OF THE RADIUM 

EMANATION. 

By E. RUTHERFORD, F.R.S. 

In 1906 [Nature, Oct. 25), I drew attention to the fact 
that the emanation of radium, thorium, and actinium were 
completely absorbed by cocoanut charcoal at ordinary 
temperatures. I have had occasion recently to repeat 
these experiments with much larger quantities of radium 
emanation, and have found that the actual volume of 
emanation capable of absorption by charcoal at room 
temperature is very small. For example, several grms. of 
cocoanut charcoal are required to absorb completely the 
emanation from 200 mgrms. of radium at ordinary tem 
perature although the volume of the gas is only one-tenth 
of a cubic mm. As was to be expected, the absorptive 
power of charcoal for the emanation increases rapidly with 
lowering of the temperature. This was investigated as 
follows : — A quantity o-8 grm. of cocoanut charcoal, which 
absorbed about 4 cc. of air at the temperature of 
liquid air, was connected with a pump, and the air com- 
pletely removed by heating the charcoal. The charcoal 
was then surrounded by a pentane bath at — 150° C, and 
the purified emanation from 83 mgrms. of radium (about 
0-05 cubic mm.) absorbed in it. As the temperature of the 
bath slowly rose, the unabsorbed emanation was allowed 
to expand into an exhausted receiver of about 50 cc. 
capacity. This was pumped out at different temperatures 
of the charcoal, and the emanation collected and after- 
wards measured by the y-ray method. At - 50° C. the 
amount of unabsorbed emanation was less than one-tenth 
per cent of the total. Above -40" C, the emanation 
commenced to escape rapidly, and half had been pumped 
off at a temperature of 10° C. About 19 per cent remained 
in the charcoal at loo*^ C, but practically all was released 
at a temperature of the softening of glass. It is seen from 
these results, that at 10° C. the charcoal absorbs about 
0-03 cubic mm. of emanation per grm., and at — 40°C. 
about 006 cubic mm. per grm. 

An experiment was shown to illustrate the rapidity of 
condensation of pure emanation contained in an exhausted 
vessel when one point was cooled to the temperature of 
liquid air. — Memoirs and Proceedings of the Manchester 
Literary and Philosophical Society, vol. liii., Part I. 



FURTHER INVESTIGATION OF THE 
TOMIC WEIGHTS OF NITROGEN AND SILVER.* 

By THEODORE WILLIAM RICHARDS, PAUL KOTHNER, 
and ERICH TIEDE. 

(Concluded from p. 66). 

Analysis of the Ammonium Chloride. — In the present re- 
search the amount of chlorine present was determined by 
precipitating the halogen as silver chloride and weighing 
this substance. A further check upon the method, obtained 
by finding the silver necessary for precipitation, was not 
completed for lack of time, but this further step is now 
being taken in the Chemical Laboratory of Harvard 
College. The method of analysis is so similar to that 
used in the case of sodium and potassium chlorides that 
few words need be spent upon the description (Publications 
Nos. 28 and 69 Carnegie Inst, of Washington). In the 
first place exactly the equivalent amount of silver was 
added to effect the precipitation, and then after much 
shaking and long standing, a slight excess of about 005 
grm. per litre of silver nitrate was added. Filtration was 
effected by means of the Gooch-Munroe-Neubauer crucible 
with the help of the water-pump The first two washings 
were made with water containing a trace of silver nitrate, 
then three further washings with about 0-2 litre of pure 



* Journal of the American Chemical Society, xxxi., No. i. 



water each were used, and then 3 to 5 washings with small 
volumes of water containing nitric acid. Afterwards the 
precipitate was conveyed with the greatest care by means 
of a jet of water driven by hydrostatic pressure into the 
crucible, and finally the flask was rinsed with ammonia, 
and the solution tested in the nephelometer in ord^r to 
be sure that every trace of silver chloride had been 
collected. The further drying and fusing of the silver 
chloride happened precisely in the usual way, and the pro- 
duct was as pure and white in appearance as could have 
been desired. Concentrated ammonia was used to remove 
traces of silver chloride from the perforated crucible in 
order to prepare it for further work. 

The determination of the silver chloride dissolved by the 
wash waters, one of the most important parts of the whole 
proceeding, occurred in the usual way with a nephelometer, 
proceeding as has already been described by Richards and 
Staehler. The weighing was conducted entirely by 
methods of substitution as usual, and all the weights were 
corrected to the vacuum standard. In view of the fact 
that the details are essentially like the previous work of 
the kind, further particulars are unnecessary, and the final 
table of results may be given at once. This table contains 
only those analyses which were believed to be free from 
error. Two preliminary determinations, vitiated by inex- 
perience, were rejected. Four other experiments also, 
Nos. 5, 6, 8, and 10, were likewise rejected, because of the 
small amount of material used, averaging less than a grm. 
in these cases. One of these four, No. 6, was known to 
be in error for other reasons. The three of these which 
might possibly have been included, namely, Nos. 5, 8, and 

10. would have made very little difference in the final 
result, but it was thought safer to exclude them, because 
the method is too complicated to yield satisfactory results 
with 80 small a quantity of substance. 

Ratio of Argentic to Ammonic Chloride 

(Final Results). 

Ag= 107-881; 01 = 35-4574; H = 1-0076. 

Atomic weight 
of nitrogen. 
NH4CI AgCl AgCl:NH4Cl Ag = io7-88i. 

No. Sample, (inv.icuo). {in vacuo). =ioo:;tr. Cl=- 35'4574- 

x= H= 1-0076. 

Grms. Grms. N = 

3. C 2-02087 5-41469 37-3220 14-009 

4. A' 2-23894 5*99903 37'32i7 i4'Oo8 
7. B i'55284 4-16076 37-3211 14008 
9. A 1-36579 3"65959 37-3209 14-007 

11. B 1-61939 4'339i4 37*3205 14007 

12. D 1-93795 5'i92i9 37"3243 14012 
13- D 2-89057 774498 37'32i9 14-009 

14. B i'3i405 3-52082 37-3223 14-009 

15. B 1-82091 4-87921 37-3198 14-006 



Average 37'32i7 14-0085 

Probable error i 0-0004 

(The analyses tabulated in this list were all made in 
Berlin by E. Tiede, with the immediate collabora- 
tion of P. Kothner, after T. W. Richards had been 
obliged by his duties in Harvard University to 
return to America). 

Discussion of the Results. — From these figures it is clear 
that the atomic weight of nitrogen cannot be far from 
14-008 if silver is taken as 107-88. The results agree with 
one another as well as could reasombly be expected. The 
maximum deviation from the mean is 4 in the third decimal 
place, and in no other case does the deviation exceed 2. 
The average deviation from the mean is only about i in 
the third decimal place, and the probable error calculated 
according to the theory of least squares is ^00004. This 
probable error of course gives no clue to any constant 
error which may possibly have escaped detection, but its 
small value shows at least that further repetition of the 
process by this method is not necessary. 



Chemical News, ) 
Feb. 12, 1909 I 



Tantalum and Niobium in Australia. 



77 



It is interesting to compare the results from the four dif- 
ferent samples of ammonium chloride. Sample A and A' 
were made from ammonia prepared from ammonium sul- 
phate oxidised by nitric acid, and by sulphuric acid with 
permanganate. The preparation of the salt occurred in 
the case of A in quartz dishes, in A' in platinum dishes. 
The results of these two are essentially identical, giving an 
average of i4-oo75. Sample B was made from ammonia 
prepared by the electrolytic reduction of nitric acid, 
neutralised with pure hydrochloric acid in quartz vessels 
alone. The four analyses of this substance gave exactly 
the same result, on the average, 14-0075. Samples C and 
D, which were made, the one in Germany and the other 
in America, by the action of nitric acid on ammonium 
chloride gave a slightly higher value, the average of the 
three being i4"oio. It is probable that the method of pre- 
paration in these cases was not so effectual as in the 
others ; small quantities of carbon compounds may have 
still remained in the material. The number of analyses is, 
however, too small to make certain of this difference, 
which is at worst very slight ; and accordingly the results 
may be averaged in with the others without causing 
serious error. 

The relation of these results to other atomic weights is 
very far-reaching and important. Clearly, they connect the 
atomic weight of nitrogen with that of hydrogen, silver, and 
chlorine, and therefore with the help of other well-known 
relations affect the atomic weight of each of these elements 
in relation to the other. The calculation is very simply 
carried out as follows : — 

Let— 

Agci ^ „ 

Ag 



I, 



NH4CI 
AgCl 



= b 



2, 



AgN03 = , 3. 

Ag 
The three atomic weights supposed to be unknown may 
be designated as follows: — Ag^x,C\=y, N=jj. From 
the work of Morley hydrogen may be taken as 1-0076, if 
oxygen = 16 {Am. Chem. yourn., xvii., 267 ; Zeit. Phys. 
Chem., 1895, xvii., 87). Substituting these values in 
Equations i, 2, and 3, we obtain the following : — 



X + y = ax . . 
z + y i- 4'034 = b(x + y) 
X + z + 48-000 = ex . 



Substituting in Equation 5 the value of z as found from 
Equation 6, we have — 

(i c) x~bx + (i -b)y = 43-9696, 

but according to Equation 4 j = (a-i) x ; hence — 

^ ^ 43'9696 

I -c — b + (i b)(a - i) 

The values a, b, and c are all known, a (the quantity of 
silver chloride obtained from i grm. of silver) was found by 
Richards and Wells to be 1-32867 {Publication No. 28 
Carnegie Inst. ; yourn. Am. Chem. Soc, xxvii., 526) ; c 
(the quantity of silver nitrate obtained from the same 
quantity of silver) was found by Richards and Forbes to be 
1-57479 {Publication No. 69 Carnegie Inst. ; yourn. Am. 
Chem. Soc, xxix., 826). The present investigation gives 
the value of b as 0373217, the average of the fifth column in 
the preceding table. Substituting these values in the 
Equation 7, we obtain x, the atomic weight of silver, 
= 107-881. Substituting this value in Equation 4, we 
obtain y, the atomic weight of chlorine, - 35 '4574' ^nd 
substituting these values in Equation 5 or 6, we obtain z, 
the atomic weight of nitrogen, = 14-0085. These three 
values for the atomic weights of silver, chlorine, and 
nitrogen are entirely independent of any but the most 
recent work, and rest directly, through silver nitrate 



and water, upon the international standard of atomic 
weights, = 16000. It may be noted that if hydrogen is 
taken as 1-0078 with Noyes (yourn. Am. Chem. Soc, 1908, 
XXX., 4), the values of the atomic weights are altered but 
slightly. Silver becomes 107-879, chlorine 35-456, nitrogen 
14-008, The present work thus completes a connected 
chain of data, and furnishes striking evidence in favour of 
the low values for silver and nitrogen which have recently 
found support in so many other different ways. 

It is not without interest also to note that if one chooses 
the value for silver, 107-93, and for chlorine, 35*473, the 
present work makes nitrogen 14-017 — a value inconsistent 
with the value 14037 calculated from silver nitrate, if 
silver is assumed as 107-93. Thus the present results are 
incompatible with the work of Stas, both as regards silver 
and as regards nitrogen. 

Summary. 

In the present paper is described a series of analyses of 
ammonium chloride. These analyses were superior to any 
other that have ever been made in respect, first, to the 
purity of the material ; second to the choice of conditions 
for subliming the salt; and third, to the accuracy of the 
analyses. The ammonium salt was prepared in such a way 
as to render the presence of amines very unlikely ; the sub- 
limation was conducted first in a current of ammonia, and 
then the same substance was re-sublimed in a vacuum ; 
the analysis was carried out with all the care used in the 
recent work in Harvard University, taking due account of 
the solubility of silver chloride. As a result, it was found 
that if oxygen is taken as 16-000 and hydrogen as 1-0076, the 
three following values result: — Ag= 107-881, Cl = 35-457, 
and N = 14-008. 



TANTALUM AND NIOBIUM IN AUSTRALIA. 

By EDWARD S. SIMPSON, B.E., F.C.S., 
of the Geological Survey of Western Australia. 

(Concluded from p. 52. 

The mineral which occurs most frequently at Wodgina, 
and constitutes almost the whole bulk of the ore exported, 
is manganotantalite. A typical fragment from a large 
specimen of detrital ore from miscellaneous lease 86 was 
analysed with the results given in Column A. Those in 
Column B were obtained from a single rhombic prism 
weighing 8 grms. 

^ A. B. 

Tantalum pentoxide 68-65 69-95 

Niobium pentoxide 15-11 I4'47 

Titanium dioxide 0-40 — 

Tin dioxide 0-48 0-36 

Tungsten trioxide Trace — 

Water combined 0-07 — 

Iron protoxide i'63 268 

Manganese protoxide i4'i5 (12-54) 

Nickel protoxide Trace — 

Lime Trace — 

Magnesia 0-15 — 

Cerium and yttrium oxides . . . . Nil Nil 



Total . . . . 
Specific gravity 



100-64 
7 '03 



loo-oo 
7-og 



This mineral is black on a fresh fracture with a metallic 
lustre. Weathered surfaces are a rusty-brown colour, due 
largely to a thin adhering film of ferruginous clay. The 
masses, whether of lode or detrital ore, frequently consist 
of an intergrown mass of parallel prismatic crystals, in 
which the faces a, b, and c are freely represented, and, less 
commonly, u (133). These primatic masses are inclined 
at times to be wedge-shaped, and, rarely, small masses are 
seen to be part of a spherical " rosette " or radiated crystal 
group. The faces are frequently indented by actual 
tabular crystals of albite, or by hollows from which albite 



78 



Tantalum and Niobium in Australia. 



Chem cal New 
Feb. 12, 1909 



has evidently been weathered out. Twinning about the 
plane e has been obseived in several instances. The 
macropinacoid a is often vertically striated, and at times 
has a very brilliant lustre. In size the masses vary from 
many pounds in weight down to a few grains only, and in 
the alluvial are often associated with tin ore, though so 
far cassiterite has not been recorded from the veins which 
carry tantalite. 

No normal iron tantalite has been observed at Wodgina, 
the whole of the tantalite there being of the manganese 
variety. It is usually of very uniform grade, containing 
from 65 per cent to 70 per cent of tantalic oxide. Man- 
ganocolumbite has, however, recently been obtained at 
Wodgina. This is identical with the richer ore, in all 
physical features, with the exception of specific gravity, 
which, as one would expect, is correspondingly lower. 
Specimens of this mineral, and of an ore of intermediate 
composition, gave the following results. 

Tantalic oxide. Niobic oxide .Sp.gr. 
Manganocolumbite .. .. 22-90 54"83 yjz 

Low-grade manganotantalite 48-21 30-52 634 

In "Dana's Mineralogy" there is a list of analyses of 
tantalitecolumbite from the Etta Mine in the Black Hills 
of South Dakota, which show to what a large extent the 
ore in a single mine may vary in grade owing to the 
mutual replacement of tantalum by niobium, and vice 
versa. As has already been stated, this is not characteristic 
of most of the Wodgina deposits. The exception that 
proves the rule, however, is a small parcel of crystalline 
stream ore, individual fragments of which gave the following 
specific gravities: — 5-98, 6-io, 6-55, 6-92, 7-03, 7-75, 8-03. 
These figures show that this ore ranges from nearly pure 
niobate of manganese to a nearly pure tantalate of iron. 

Tin oxide appears to exist as an essential constituent of 
all tantalates and niobates. The amount thus present 
seldom exceeds i per cent, and, not being recoverable by 
any simple process, is of no importance to the miner. A 
mechanical mixture, however, of cassiterite and tantalite or 
columbite is readily separated by an electro-magnet, so 
that the cassiterite which thus occurs with almost all 
Wodgina stream ores is not to be overlooked. The fol- 
lowing figures give an idea as to the extent to which the 
tin thus occurs : — 

Sample. Tantalic oxide. 

Per cent. 
A .. .. 45 
B .. .. 5o 
C .... 17-3 
D .. .. 89 

Microlite (pyrotantalate of lime) occurs in association 
with manganotantalite in a stream ore received from 
Wodgina. The exact locality from which this ore was 
derived has so far not been disclosed, but, judging from the 
associated minerals, it is from the immediate vicinity of 
Wodgina itself. The mineral, constituting about 2 per 
cent of the whole parcel, is in irregular water-worn frag- 
ments up to I in. in diameter. By the courtesy of Mr. 
A. O. Watkins I have been supplied recently with about an 
ounce in weight of this mineral, and a preliminary physical 
and chemical examination of it has been made. 

The specific gravity of five fragments was respectively 
5'37> 5'76. 5'6i, 5-42, 573, evidencing a somewhat small 
variation in tantalum contents (probably about 15 per cent). 
No evidence of crystallisation is apparent, the fragments 
being roughly rounded and water-worn. Parts of the sur- 
face are covered with a very thin black coating, which 
sends out what one may call small rootlets into the mass 
of the mineral. This coating, as well as more or less 
numerous minute black inclusions in the centre of the 
pebbles, appears to consist of tantalate of manganese. 
Wiiere not covered with this black coat the microlite 
pebbles are grey or light pinkish brown. On fresh fractures 
the mineral is opaque and usually light pinkish grey, some- 
tinjes a little darker, and inclined to liver-colour. The 



Niobic oxide. 


Metallic tin 


Per cent. 


Per cent. 


32 


3-12 


16 


6-74 


3'5 


50-35 


1-6 


60-90 



internal structure as seen in a thin slice under a microscop e 
is very interesting, being reminiscent of olivine largely 
altered to serpentine. It consists of numerous cores of 
clear unaltered isotropic microlite enclosed in a mesh- 
work of the same mineral, more or less cloudy, and 
evidently altered somewhat — probably, judging from the 
analysis, by absorption of water. Throughout the section 
are tiny pin-points of black manganotantalite. 

A fragment of a pale pinkish colour, which on sectioning 
was found to be practically free from included tantalite, 
was chosen for analysis. It has, unfortunately, not been 
found possible so far to complete this analysis, but the 
following are the results obtained up to the present : — 

Tantalum pentoxide I 

Niobium pentoxide | 77 i" 

Lime 13*46 

Magnesia 0-42 

Iron protoxide 3-64 

Manganese protoxide o-6o 

Potash 0-20 

Soda 1-66 

Water on ignition i-o6 

Water at 100° . . 0-22 



98-42 
Specific gravity 5'422 

The analysis proves this mineral to be essentially a pyro- 
tantalate of lime of the form Ca2Ta207, part of the lime 
being replaced by alkalis, iron oxide, &c. Like most 
tantalum minerals, it probably carries a little tin oxide, 
which has not been estimated. 

Of interest in this connection are a few small pebbles 
received on another occasion from Wodgina. One consists 
of a large core of a dark coloured tantalate, completely 
surrounding which is a layer about 5 millimetres thick of 
pale microlite similar to that described above, covered in 
its turn again by a very thin coating of black tantalite. A 
second pebble is similar, whilst two others are wholly 
composed of a greyish black opaque and apparently 
homogeneous mineral. One of these latter pebbles, 
weighing 18 grms., was broken in half, and one half 
analysed with the following result : — 

Tantalum pentoxide 73*82 

Niobium pentoxide 6-44 

Tin dioxide 0-72 

Titanium dioxide 0-54 

Iron protoxide 8-42 

Manganese protoxide 1*39 

Lime 7-78 

Magnesia 062 

Cerium and yttrium oxides Nil 



^ .. . 9973 

Specific gravity 6 04 

Without further investigation it is impossible to say 
whether this is only a very intimate intergrowth of 
microlite and tantalite, or, as I am inclined to think, a new 
sub-species of tantalite, in which lime to a large extent 
replaces iron oxide. If the latter be the true explanation 
of the observed facts, the name calciotantalite naturally 
suggests itself as descriptive. 

Mount Francisco. — This locality is about 15 miles south- 
west of Wodgina, and has only recently been discovered. 
According to accounts of the field received in Perth, the 
ore occurs under similar conditions to those which obtain 
at Wodgina. The mineral, however, contains much less 
tantalum, being a manganocolumbite with specific gravity 
5-73, equal to 23 per cent of tantalic oxide. The pegmatite 
in which the ore occurs is composed mainly of albite, 
orthoclase, and quartz, with more or less muscovite and 
garnet. The columbite is in irregular masses, in which 
parallel groups of crystals are often well defined. The 
faces most commonly developed are a (striated), b, and Ji. 
Twinning on e was observed in one case. Small parallel 



Chemical News, 
Feb. 12, igog 



Tantalum and Niobium in Australia. 



crystals are developed in great numbers at times on the 
macropinacoid a. 

A little detrital ore has been obtained from this locality. 
It is thickly coated with ferruginous clay, which is suffi- 
ciently adherent to give a rusty-black colour to the ore, 
even after hard scrubbing with water. The actual ore 
itself does not apparently weather readily, as careful 
cleaning reveals bright black faces. The ore has not 
travelled far, as excellent crystals with sharp edges occur 
amongst it. 

Greenbushes. — The last locality to be described was 
almost the first in which tantalum and niobium were 
recognised in Australia. It is interesting also as being the 
scene of the first mining for tantalum or in the Common- 
wealth, a lease having been secured and worked in 1902 to 
provide tantalite for the Foote Mineral Company of the 
United States. 

Greenbushes is situated in the Blackwood Ranges. The 
prevailing rock on the surface is a laterite composed largely 
of bauxite, and completely concealing the underlying 
primary rocks from view except in a few isolated areas 
adjacent to streams. The country appears to be mainly 
granite, traversed by dykes of diorite and pegmatite, all 
foliated more or less strongly in places. Considerable 
quantities of tin ore have been recovered from the streams 
and older gravels and cements, smaller quantities from the 
pegmatite dykes and foliated bands of greisen. 

In 1893 Mr. J. J. East, of the Adelaide School of Mines, 
in examining some alluvial tin ore from Greenbushes, 
turned his attention to a mineral present in it, which had 
been looked upon by the miners as " resin tin," or in some 
cases as scheelite. A few blowpipe tests revealed the fact 
that this mineral was a new compound of antimony. It 
was therefore submitted for analysis to Mr. G. A. Goyder, 
who established the fact that it was a tantalate and 
niobate of antimony. This new mineral species was sub- 
sequently named stibiotantalite. 

Although only present in the ores from the southern part 
of the field, and even then in quantities not exceeding 
I per cent or 2 per cent, stibiotantalite threatened at one 
time to become a serious trouble to the tin miners, as the 
antimony from it found its way into all the smelted tin, 
and reduced its value by about £10 per ton. It would 
appear to have almost disappeared from the ores raised in 
recent years, only occasional very small fragments being 
seen in the concentrates. 

In 1900, at the time when the author was examining 
some of the antimonial tin ores with a view to suggesting 
a method of treatment, trouble was again experienced at 
Greenbushes with a second class of concentrates. Some 
apparently clean tin concentrates from alluvial ground 
refused to yield up any tin either in the assay pot or in 
the smelting furnace. Several samples of this mysterious 
ore were forwarded to the author, and proved to be tantalite 
of the normal iron variety. No other tantalum minerals 
have so far been detected at Greenbushes, except a doubtful 
new species, a hydrated tantalate of antimony, which will 
be described later. 

Very little lode mining has been done at Greenbushes, 
either for tin or tantalum ; the total tantalum ore ex- 
ported — 2j tons — having been obtained almost exclusively 
from alluvial workings. The principal lode workings are 
at the head of Bunbury Gully, on mining lease 369 
(Enterprise), where there is an ore body 18 inches wide, 
consisting of a crushed rock composed almost wholly of 
pale-green mica with accessory quartz, tourmaline, cas- 
siterite, and tantalite in fragments from the size of sand up 
to an inch in diameter. Overlying the lode is 12 feet of 
alluvial, carrying fine and coarse tinstone and tantalite. 

On mining lease 379 (Galtee More), one mile further 
south, a decomposed lode of apparently similar character 
carries tin and tantalite. Some lode tin concentrates from 
mining lease 56 (Amanda), lying between these two, was 
found to yield on assay 5*5 per cent of mixed tantalic and 
niobic oxides. This ore is described as coming from a 
weathered tourmaline bearing dyke. 



79 



The alluvial tantalite at Greenbushes occurs principally 
in Bunbury and Floyd's gullies, in fragments from the 
size of sand grains up to lumps 13 lbs. in weight. Its 
composition is not very variable, and, as shown by the 
following analysis of a typical fragment, it is a high-grade 
ore, occurring, unfortunately, in very limited quantities. 

Tantalum pentoxide 8o-6i 

Niobium pentoxide 2-50 

Tin dioxide I'^i 

Titanium dioxide 071 

Tungsten trioxide 0-13 

Water combined 0-14 

Iron protoxide io"8q 

Manganese protoxide 378 

Nickel protoxide 0-02 

Lime Nil 

Magnesia o-ig 

Cerium and yttrium oxides Nil 



100-48 
Specific gravity . . . . . . 7-74 

This specimen, like all others from Greenbushes, showed 
no traces of crystal faces but exhibits an ill-defined cleavage. 
Dr. G. F. Kunz reports that its radio-activity is less than 
002 times that of uranium. The mineral is of a brownish- 
black colour, and on a fresh fracture has a bright metallic 
lustre. Some fragments are wholly or partially coated 
with a smooth, hard, and strongly adherent coating of 
ferruginous bauxite, as much as 3 or 4 millimetres thick 
in places. This peculiarity extends to the tin ore also. 
Other fragments have no decided coating, but a slightly 
rusty tinge, which enables them to be readily picked out 
from the associated tin ore. Quartz, weathered felspar, 
and stibio-tantalite are found adherent to it, whilst 
associated with it in the gravels are cassiterite, tourmaline, 
quartz, mica, cyanite, and other minerals. 

The most interesting mineral found at Greenbushes is 
the previously mentioned stibiotantalite. This has not 
yet been located in lode material ; but in some parts of 
the southern part of the field was at one time somewhat 
plentiful in the stream deposits. It was never shown to 
exist in amounts which would justify its being put on the 
market as a tantalum ore, and as time goes on it appears 
to become more and more rare. Greenbushes was, up till 
recently, the only known locality for this mineral, but 
quite recently well-defined orthorhombic crystals have been 
found at Mesa Grande, California, in a pegmatite vein, 
with tourmaline, beryl, &c. 

The chemical composition of the Greenbushes mineral 
is shown by the following two analyses by Mr. G. A. 
Goyder : — 

A. 

Tantalum pentoxide 5113 

Niobium pentoxide 7-56 

Silica — 

Combined water — 

Antimony trioxide 4023 

Bismuth trioxide 0-82 

Iron peroxide Trace 

Manganese protoxide — 

Nickel protoxide 08 

Copper oxide — 

9982 



B. 

51-95 
449 
3 H 
o 61 

3804 

079 

039 

Trace 

Trace 

0-20 

99-61 



Specific gravity 737 6-47 

Its ormula is Sb(TaNb)04, or more probably, according 
to Penfield and Ford, (SbO)2(TaNb)206. which would 
explain the resemblance of its crystals to those of colunihite. 
Two well-marked features of the Greenbushes ore are of 
great interest, as indicating the probable origin of the 
mineral. In the fiist place stibiotantalite is often seen 
filling minute veins and occupying small vughs in masses 
of tantalite. Secondly, a very large number of the water- 
worn pebbles contain a central core of tantalite, the 
boundaries of which are very irregular, and which pene- 



8o 



Chemical Examination of Eriodictyon. 



i Chemical News, 
I Feb. 12, 1909 



trates often in thin tongues out into the surrounding stibio- 
tantalite. It would appear that the original mineral has 
been tantalite, and that this has been more or less replaced 
by pseudomorphs of stibiotantalite on the infiltration at a 
later stage of antimonial solutions into the lodes. 

Greenbushes stibiotantalite exhibits only occasional 
traces of an external crystalline form : the only faces 
recognised with any certainty are a and b, with possibly 
m and u. A very distinct cleavage parallel to the macro- 
pinacoid is almost invariably noticed, and at times traces 
of a second cleavage have been seen. In colour and 
transparency it varies very largely. Many sniall fragments 
are perfectly transparent, and of a pale lemon-yellow or 
amber colour ; the greater part of the ore is, however, 
more or less opaque, and varies in colour from light yellow 
or grey to brown or even dull black. Some of the more 
opaque mineral is cellular in structure, shows no cleavage, 
has a dull rough surface, and breaks with an uneven frac- 
ture. This may be an alteration product of true stibio- 
tantalite, one such specimen yielding an amount of water 
of combination expressed by the formula (SbO)2Ta206 7 H2O. 
Such a fragment had a specific gravity of only 477. In 
the unaltered stibiotantalite Goyder found a range in 
specific gravity from 647 to 7"37. The author has made 
the following specific gravity determinations, amongst 
others: — 6-41, dark yellow pebble; 6-75, grey pebble; 
7'i8, grey pebble, with yellow veins, strong cleavage ; 
7*43, pale lemon-yellow, indistinct crystal ; 7'48, dark 
yellow crystalline ; 7'50, pale greyish yellow, indistinct 
crystal. The bulk sample from which most of these 
pieces were taken assayed tantalic oxide, 5057 per cent ; 
niobic oxide, i2"58 per cent A second bulk sample 
assayed tantalic oxide, 5i'i3 per cent; niobic oxide, 
7-56 per cent. 

The stibiotantalite occurs in fragments from the size 
of a pin's head up to about i inch in diameter. A single 
exceptionally large crystalline mass, about 2i inches in 
diameter, is in the possession of the Foote Mineral 
Company. 

This mineral has been examined for radio-activity, with 
negative results, by Messrs. Mawson and Laby. 

Conclusion. 
In conclusion I desire to express my indebtedness to 
several gentlemen for the material information obtained 
from their letters or published papers. Amongst others, I 
am specially indebted to Messrs. A. Gibb Maitland, C. W. 
Marsh, G. A. Goyder, D. Mawson, and J. C. H. Mingaye. 



PROCEEDINGS OF SOCIETIES 

CHEMICAL SOCIETY. 
Ordinarv Meeting, yamiary 2is^ igog. 

Sir William Ramsay, K.C.B., F.R.S., President, 
in the Chair. 

(Concluded from p. 70). 
*4. " Synthesis of Para-urazine from Carbamide." By 
Frederick Daniel Chattaway. 

By means of dichlorocarbamide, NHCl-CO-NHCl, 
recently described by the author {Proc. Roy. Soc, 1908, 
Ixxxi., A, 381), carbamide can be very simply converted 
into ^-urazine, which has hitherto only been obtained by 
the employment of hydrazine. All that is necessary is to 
add an aqueous solution of dichlorocarbamide to a strong 
solution of ammonia, when />-urazine, which is very 
sparingly soluble in water, separates as a white, crystalline 
precipitate. 

In the reaction, one of the chlorine atoms of the dichloro- 
carbamide is probably replaced by hydrogen, two molecules 
of the resulting monochlorocarbamide then condensing 
under the influence of the ammonia, thus ;— 



PP.^NHH , CIHN^^,. , ,,„ 
^0<NHC1 + HHN>C^ + 2NH3 = 

= co<j5h;nh>co^-2NH4C1. 

^-Urazine is readily hydrolysed when heated with concen- 
trated sulphuric acid, carbon dioxide and hydrazine sulphate 
being produced, thus : — 

C2H4O2N4 f 2H2O ^2H2S04 = 2C02 + 2NH2-NH2,H2S04. 
This reaction furnishes a very simple method for the 
preparation of small quantities of hydrazine. 

Discussion. 
Dr. Hewitt called attention to the analogy between 
Dr. Chattaway's process for obtaining hydrazine and the 
method devised by Raschig, namely, the direct action of 
hypochlorites on ammonia. 

*5. '^Chlorine Derivatives of Substituted Carbamides." 
By Frederick Daniel Chattaway and Donald 
Frederick Sandys Wunsch. 

The action of chlorine on carbamide should give rise to 
a monochloro-, a symmetrical and an unsymmetrical 
dichloro-, a trichloro-, and a tetrachloro-carbamide. Of 
these, only the s-dichloro-derivative has so far been iso- 
lated. The action of chlorine on a number of substituted 
carbamides has been studied, and it has been shown that 
in such compounds it is possible to replace by chlorine all 
the hydrogen attached to nitrogen, atom by atom. 

Compounds of the types NHRCONHCl, 
NCIRCO-NHCI, NC1R-C0NC12, NCIRCONCIR, and 
NR2'C0-NCl2 have been obtained, R being an acyl or an 
alkyl group. 

The monochloroacylcarbamides are beautifully crystal- 
line solids, which are among the most stable of the 
nitrogen chlorides known. The acyl compounds con- 
taining more chlorine, and most of those containing an 
alkyl group, are liquids which decompose easily on 
heating. 

Nearly all of the possible chlorine derivatives of acetyl-, 
benzoyl-, methyl-, s- and as-dimethyl, ethyl, 5-diethyl-, 
and benzyl-carbamide have been prepared. 

It is thus proved that in carbamides the replacement of 
one hydrogen atom by chlorine does not prevent in any 
way the replacement of the second hydrogen atom attached 
to the same nitrogen. 

There is every reason, therefore, to believe that the 
action of chlorine on carbamide itself gives rise to the 
other theoretically possible chlorocarbamides, and that 
these will be obtained when the conditions under which 
they can exist are ascertained, and when the difficulties 
attending their isolation have been overcome. 

*6. " Chemical Examination of Eriodictyon." Part II. 
By Frank Tutin and Hubert William Bentley 
Clewer. 

Eriodictyon leaves were shown by Power and Tutin 
[Proc. Am. Pharm. Assoc, 1906, liv., 352) to contain, in 
addition to other compounds, three new crystalline sub- 
stances of a phenolic nature, namely, eriodictyol, C15H12O6 
(m. p. 267°), homoeriodictyol, C16H14O6 (m. p. 223°), and 
a third substance, possessing the formula C16H12O6, which 
occurred only in very small amount. 

The present authors have employed a larger amount of 
the extract of eriodictyon leaves, and, after a prolonged 
process of separation, have isolated a larger amount of 
the last-mentioned compound, together with two new 
substances. 

Chrysoeriol, C16H12O6, the substance previously isolated 
in small amount, forms golden-yellow leaflets, and does 
not melt at 337°. It contains three hydroxyl groups, and 
yields]triacetylchrysoeriol, Ci6H906(CO-CH3)3, which melts 
at 211 — 212". 

Xanthoeridol, Ci8Hi407, crystallises in yellow 
needles melting at 258°. Triacetylxanthoeridol, 
Ci8Hii07(C0-CH3)3, melts at 175—176°. 

Eriodonol, C19H18O7, separates from dilute alcohol in 
pale yellow needles, which contain one molecule of water 



Chemical News, I 
Feb. 12, igog J 



Nitrogen Chloride. 



8i 



of crystallisation and melt at 199° ; the anhydrous sub- 
stance melts at 209°. It yields a tetra-acetyl derivative 
melting at 131°. 

"7. " The Hydration of Precipitates." By Spencer U. 
Pickering. 

Many substances which are precipitated from aqueous 
solution are capable of emulsifying oils, and, by adjusting 
the amount of oil in the emulsion, the latter may be 
obtained of the same density as the liquid. By deter- 
mining the density of this liquid, the density of the oil, 
and that of the precipitate in the anhydrous conditions, 
and by ascertaining the vi'eight of oil required to float a 
given weight of precipitate in two liquids of different 
densities, the weight of water combined with the anhydrous 
precipitate may be determined. The precipitate selected 
was the compound ioCuO,S03,CaS04,Na2S04, which is 
of uniform composition when thrown down by adding 
lime-water to copper sulphate in the presence of varying 
quantities of sodium sulphate. The amount of water com- 
bined with it was found to be about 42H2O. It was also 
ascertained that the water possessed the same specific 
gravity of ice, as in the case of the water of crystallisation 
of most hydrated salts. 

Discussion. 

The President called attention to the fact that Dr. 
Chichester Bell had, more than ten years ago, made ex- 
periments on the velocity of sound in melted ice at -f-o'5°, 
and in cooled water at the same temperature. The 
velocities appeared to differ. Experiments by Dr. Wils- 
more, unpublished, on the density of melted ice, and of 
cooled water, were indecisive, owing to the lapse of time 
before an accurate density could be determined. 

He also reminded Mr. Pickering that Playfair and Joule 
had concluded from their experiments that " water of 
crystallisation " has the same molecular volume as ice. 

*8. " Studies of Dynamic Isomerism. Part VIII. The 
Relationship between Absorption Spectra and Isomeric 
Change. Absorption Spectra of Halogen, Nitro-, and 
Methyl Derivatives of Camphor." By Thomas Martin 
LowRY and Cecil Henry Desch. 

The band noted by Baly and by Hartley in the ultra- 
violet absorption spectrum of camphor at a concentration 
of N/io appears also in the spectrum of /8-bromocamphor ; 
in both cases the band is weakened by diluting to N/ioo, 
but is restored by the addition of alkali. A similar band 
of rather greater intensity is seen in the spectrum of 
a-bromocamphor at a concentration of N/ioo ; as this 
band is developed by neutral solutions in which the 
o-bromo-compound is stable, and is only slightly in- 
tensified when a condition of equilibrium between iso- 
merides is set up by the addition of alkali, its appearance 
cannot well be associated with the occurrence of reversible 
isomeric change. 

No marked change is seen in the absorption spectrum of 
a-bromo-camphor when a halogen is introduced into the 
l3- or ir-position, but the band is no longer developed when 
the second a-hydrogen atom is displaced by a halogen or 
by a nitro-group ; it may therefore be associated with the 
presence of a displaceable hydrogen atom in the group 
— CHX-CO — , although not dependent on any actual 
transference of the atom ; a'-bromo-a-methykamphor 
appears, however, to produce a shallow band. 

The weak band of nitrocamphor is greatly intensified by 
alkalis, but does not appear in the spectrum of the an- 
hydride derived from the pseudo-form ; it is therefore 
dependent on the presence of a displaceable hydrogen 
atom rather than on the occurrence of a pseudo-nitro- 
structure. The 3- and ir-bromo-derivatives behave like 
nitrocamphor, but the o-halogen derivatives, which do not 
undergo isomeric change in solution, produce no absorp- 
tion band. Nitrocamphane does not give rise to a band 
either alone or in presence of alkali. 

9. "The Relationship between the Constitution and the 
Absorption Spectra of Pyridine and various Derivatives." 
By John Edward Purvis. 



The absorption bands of 3 : sdichloropyridine, two 
isomeric trichloropyridines, two isomeric tetrachloroamino- 
pyridines, a-picoline and several of its derivatives, 2:4:6- 
trimethylpyridine and several of its derivatives, and chloro- 
lutidine have been investigated. 

The results showed that :— (i) The general effect of 
introducing atoms or groups of atoms into the nucleus is 
to increase the persistence of the absorption band as well 
as to shift it towards the red end of the spectrum, whilst 
when they are introduced into the side-chains they generally 
decrease the persistence. (2) The weighting of the nucleus 
does not, however, always mean that the absorption band 
is shifted towards the red end. The type and the spatial 
position of the introduced atoms or groups are factors in 
determining the absorption. (3) In isomeric substances, 
the spatial positions of the substituting atoms in the 
nucleus are of considerable importance in influencing the 
position and the persistence of the absorbed rays. (4) The 
substitution of atoms in the side-chains does not exert the 
same marked influence as when they are substituted in the 
nucleus. (5) The addition of hydrochloric acid to 2 : 4 : 6- 
trimethylpyridine and a-picoline (as well as to pyridine and 
lutidine) exerts a marked influence on the vibrations of the 
nucleus, and the effect is very similar to that produced 
when chlorine atoms are introduced into the nucleus. 

Considerations on the influence of the changing valency 
of the nitrogen atom and other conditions in explanation 
of these facts were discussed. 

10. " The Action of Mustard Oils on the Ethyl Esters 
of Malonic and Cyanoacetic Acids." Part II. By Siegfried 
Ruhemann. 
The author showed that each of the cylic compounds : — 



/CH2- 



-CO 



\ 



(C:NPh)-C(CN)-C02Et 
I. 



< 



CHa 



-CO 



C(:NPh)-C{C02Et)2' 
II. 



which he described recently (Trans., 1908, xciii., 621) as 
existing in two modifications, namely, a yellow and a 
colourless one, only occur in one form. He was led to 
this result in the course of a comparative study of these 
substances, and the similarly constituted compound : — 

XH2-C0 
S<f I . Like the latter, the yellow cyclic com- 

\C0— NPh 
pound (I.) (and also II.) condenses with aldehydes with 
the formation of compounds of the general formula 



;/ 



C(:CHR)-CO 



It was found that the same 



\C(:NPh)-C(CN)-C02Et 
products were formed from the colourless compound, and 
this fact led to the view that both specimens of I. were 
identical. The author was able to verify this conclusion. 

11. "The Interaction of Hydrogen and Chlorine." By 
David Leonard Chapman and Patrick Sarsfield 
MacMahon. 

The authors have shown that the statement of Bunsen 
and Roscoe, that the rate of photochemical action between 
chlorine and hydrogen in a mixture containing equivalent 
amounts of these gases is reduced by the addition of a 
small volume either of hydrogen or chlorine, cannot be 
substantiated. Hydrogen and chlorine prepared by the 
electrolysis of concentrated hydrochloric acid do not possess 
the alleged inhibitive influence if sufficient precautions are 
taken to exclude air. It is considered likely that the 
hydrogen used by Bunsen and Roscoe contained oxygen. 
This is the more probable, as the gas employed by them 
was prepared by the electrolysis of dilute sulphuric acid. 

12. " Nitrogen Chloride." By David Leonard Chapman 
and Leonard Vodden. 

The authors have shown by a direct analysis that the 
amount of hydrogen contained in the vapour of nitrogen 
chloride prepared by the action of chlorine on a neutral 
solution of ammonium chloride is inappreciable. In har- 
mony with this result, the ratio of nitrogen to chlorine is 



82 



Condensation of Oxymethylene Camphor. 



I Chemical News, 
I Feb. 12, 1909 



found to agree very closely with the formula NCI3. 
Gattermann's conclusion that the freshly-prepared chloride 
contains hydrogen which can only be replaced by the 
continued action of chlorine is therefore called in question. 
A method by which the ammonium chloride resulting 
from the hydrolysis of nitrogen chloride with hydrochloric 
acid can be isolated without the aid of a reducing agent 
was described. The method affords the first entirely 
satisfactory demonstration of the reversibility of the change 
expressed by the equation NH4CI + 3Cl2 = NCl3 -I-4HCI. 

13. " The Atmospheric Oxidation of ^-Methylhydrin- 
done." By Arthur Henry Salway and Frederic 
Stanley Kipping. 

/3-Methylhydrindone, C6H4<^Q*>CHMe (Kippingand 

Clarke, Trans., 1903, Ixxxiii., 913), is slowly oxidised on 
exposure to the air, giving a mixture of compounds from 
which acetic, phthalic, and benzylmethylketone-o-car- 
boxylic acid, CH3-CO-CH2-C6H4-C02H, may be isolated ; 
a small amount of a neutral compound, melting at 211°, is 
also present in the crude oxidation product. 

It is suggested that the ketonic form of methylhydrin- 
done (compare Kipping, Proc., 1902, xviii., 34) first 
undergoes change to the enolic modification, which then 
combines directly with a molecule of oxygen in much the 
same way as unsaturated compounds combine with a 
molecule of ozone ; this additive product is then decom- 
posed by water, giving benzylmethylketone-o-carboxylic 
acid, and by similar processes the latter is oxidised to 
phthalic and acetic acids. 

14. " A Glucoside from Tephrosia purpurea." (Preliminary 
Note). By George Clarke, jun., and S. C. Banerjee. 

Tephrosia purpurea, Pers. (nat. ord. leguminosce), a 
small woody annual, grows luxuriantly during the monsoon 
in many waste tracts of the United Provinces of Agra and 
Oudh. The leaves yield a crystalline glucoside on ex- 
traction with either ethyl alcohol or acetone, and subse- 
quently treating the evaporated extract with water and 
light petroleum to separate tar. The yield from one ex- 
traction is approximately 2 per cent on the dried leaves. 
The glucoside melts and decomposes at 180 — 185° (uncorr.) , 
and on hydrolysis with dilute sulphuric acid yields quercetin 
and dextrose. It appears, therefore, to be identical with 
osyritrin (A. G. Perkin, Trans., 1897, Ixxi., 1134). 

15. " Note on the Constitution of the Carhoxyl Group." 
By Ida Smedley. 

From a consideration of the physical and chemical pro- 

//^ 
perties of the carboxylic acids, the constitution .C/ II 

\0H 

is suggested for the carhoxyl group as better representing 

its physical and chemical behaviour. 

16. " The Relation between the Chemical Constitution 
and Optical Properties of the Aromatic o- and'y-Diketones." 
By Ida Smedley. 

Yellow j-dibenzoylethylene (m. p. in°) was prepared 
by condensing benzoylformaldehyde with acetophenone in 
the presence of acetic anhydride. This compound is 
identical with that obtained by Paal and Schulz (Ber., 
1900, xxxiii., 3784) by the action of heat on dibenzoylmalic 
acid. From a consideration of the solubility, melting- 
point, refractive power, and colour of the cis- and trans- 
isomerides, the yellow form, which has the greater 
solubility, lower melting-point, and greater refraction, is 
regarded as the cts-isomeride, and not the transioim as 
suggested by Paal and Schulze. These two forms furnish 
the first instance described of a marked difference in the 
refraction of cis- and fra/js-isomerides. The molecular 
refractions of the following compounds were measured : — 
Phenyl methyl diketone (Ma = 4I-32), benzoylformalde- 
hyde (Ma = 3699), Cii-dibenzoylethylene (m. p. 111°; 
Ma = 73'96), <;'a«s-dibenzoylethylene (m. p. 134° ; 
Mo = 7i'84), cij-dibenzoylphenylethylene (Ma = 99'57), 
ftj-dibenzoyldiphenylethylene(Mu t= 12276), fra«5-diben- 



zoyldiphenylethylene (Ma = 123-71). The evidence from 
a consideration of their refractive power is applied to 
determine the constitution of the a diketones and s-diacyl- 
ethylenes. Marked similarities are shown in the behaviour 
of these two classes of compounds. 

17. " The Transformation of Aliphatic Nitriles into 
Alicyclic I.mino-compounds." (Preliminary Note). By 
JocELYN Field Thorpe. 

For some time past experiments have been in progress 
having for their object the study of the conditions under 
which aliphatic dinitriles having the nitrile groups separated 
by two, three, four, &c., carbon atoms pass into the 
corresponding alicyclic imino-compounds. 

Preliminary experiments indicate that there is a greater 
tendency to form a three-carbon ring in this manner than 
a ring of four carbon atoms, but that the cjj'c/opentane ring 
is produced with most remarkable ease. 

Thus, during some experiments on the formation of the 
c/c/opropane ring by the interaction of ethyl sodiocyano- 
acetate and ethylene dibromide, Carpenter and Perkin 
{Trans., 1899, Ixxv., 921) isolated, as a by-product, a 
substance which melted at 119-5°, ^""^ ^° which they 
assigned the formula CNCH2-CH2-CH2-CH(CN)-C02Et 
(ethyl o5-dicyanovalerate), owing to the fact that it yielded 
adipic acid on hydrolysis with alkaline hydrolysing agents. 

It is now found that this substance is ethyl 2-imino-3- 
cyanocjc/opentane-i-carboxylate (I)., and that it is imme- 
diately converted by the action of cold concentrated 
hydrochloric acid into ethyl 3-cyanocjc/opentane-2-one-i- 
carboxylate (II). : — 



NH:C/ 



CH(C02Et)-CH2 

I 
CH(CN) CH2 

I. 



CO 



.CH(C02Et)-CH2 

XH(CN) CH2 

II. 



Ethyl 2-imino-ycyanocyc\opentane-i-carboxylate can be 
produced in almost theoretical yield by the interaction of 
ethyl sodiocyanoacetate and ethyl i-cyanocjc/opropane-i- 
carboxylate in alcoholic solution, the sole products of the 
reaction being the sodium compound of the imino-com- 
pound and ethyl carbonate ; the equation representing the 
initial and final products of the reaction is therefore as 
follows : — 

CH 
CN-CHNa-C02Et-|-C02EfC(CN)/ | %EtOH -> 

\CH2 

/CH(C02Et)-CH2 
-^ NH:C< I +C0(0Et)2. 

\CNa(CN) — CH2 

A similar condensation product is obtained when ethyl 
sodiomalonate is substituted for ethyl sodiocyanoacetate 
in the above equation. The investigation of the properties 
of these cyclic ketones is in progress. 

18. "Action of Alcohols on Metallic Calcium." By 
Frederick Mollwo Perkin and Lionel Pratt. 

When calcium is added to alcohols reaction ensues and 
the alkyloxide, Ca(0Alk)2, is produced (Proc, 1909, xxiii., 
304). The reaction, however, is generally slow, but is 
greatly facilitated by heat. Calcium hydride reacts more 
readily than metallic calcium, but the product is less pure 
than when the metal is employed, owing to impurities in 
the calcium hydride. Calcium ethoxide is soluble in 
ethyl alcohol, and crystallises with two molecules of 
alcohol of crystallisation. Other alkyloxides are not so 
readily prepared, owing to their insolubility in the alcohols. 
Calcium ethoxide has been employed satisfactorily for 
organic condensations in place of sodium ethoxide. 

19. " The Condensation of Oxymethylenecamphor with 
Primary and Secondary Amino-compounds." By William 
Jackson Pope and John Read. 

On condensing externally compensated o-phenylethyl- 
amine with rf-oxymethylenecamphor, two stereoisomeric 
products are obtained, one from each of the optically 



Chbmical News, ' 
Feb. 12, 1909 



Transport of Ions, 



83 



active components of the primary base ; a method is thus 
indicated for ascertaining whether a particular primary 
amino-compound is or is not externally compensated. The 
two products exhibit marked mutarotation, and this is 
attributed to their conversion in solution into isodynamic 
mixtures. 

d-Oxymethylenecamphor itself and its condensation 
products with aniline, />-toluidine, and i8-naphthylamine 
exhibit mutarotation in various solutions, and this is again 
attributed to isodynamic change. 

20. " Note on the Variation in the Catalytic Activity of 
Mineral Acids with Changes in their Concentration." By 
Arthur Lapworth. 

Several recent investigations (Senter., Trans., 1908, 
xci., 467; Stieglitz, Am. Chem. jfourn., 1908, xxxix., 29 
et seq. ; Acree and others, Ber., 1908, xli., 3214 et seq.) 
suggest that during certain changes, in which electrolytes 
are concerned, not only simple and complex ions are 
directly concerned, but that intramolecular changes in, 
and interactions between, non-ionised substances may 
occur, and sometimes even to the extent of being a 
necessary part of the process. 

The author recently referred to such a possibility in the 
case of esterification as accelerated by an acid (Trans., 
1908, xciii., 2196, 2197), inferring that the disproportionate 
increase in the velocity with increase in the amount of 
mineral acid may possibly be due to a secondary reaction 
of this nature. It is necessary to state that the discussion 
applied only to those cases where no relatively powerful 
base is present in such small quantity that this decreases 
rapidly on addition of mineral acid, as might conceivably 
be the condition in alcohol containing only a very little 
water ; the general case, however, comes under the dis- 
cussion mentioned, and, as has long been recognised, is 
doubtless intimately connected with neutral salt action. 

Attention must also be drawn to the fact that the ex- 
pression for \ * '— (not — y — '- ; loc. cit., p. 2107), 

which indicates the direction of change in relative quantity 
of non-ionised compounds with alteration in the amount of 
catalyst, is always positive, this not being limited even by 
the condition suggested. 

21. " The Condensation 0/ Dimethyldihydroresorcin with 
Ethylamine." By Paul Haas. 

By the action of nitrous acid on the condensation product 
of ethylamine with dimethyldihydroresorcin, a compound 

of the constitution CMe2<c[]' ' ^^ ' ^ CQ-^^ ' ^'^^ '^ 
produced. 

This substance crystallises from water with two molecules 
of the solvent, and has a very intense carmine colour ; 
when dried in a vacuum it becomes anhydrous, and is then 
dark blue. 



SOCIETY OF CHEMICAL INDUSTRY. 

(London Section). 
Ordinary Meeting, February ist, 1909. 

Dr. J. Lewkowitsch in the Chair. 

" Gun-cotton and its Manufacture." By Colonel Sir 
Frederic L. Nathan, R.A. 

Gun-cotton was discovered by Schonbein in 1846. Its 
manufacture was worked out by Von Lenk and improved 
by Abel. The raw material is cotton-waste ; this is im- 
mersed in small quantities for a few minutes in a mixture 
of nitric and sulphuric acid, the excess acid squeezed out, 
and nitration completed in earthenware pots. The acid is 
removed by centrifugalising, the gun-cotton drowned in 
water, and purified by boiling, pulping, and washing. 

The nitration process has been modified of late. In one 
case the nitration is completed in the original dipping-pan, 
in another it takes place in the centrifugal itself. A third 
process, th Thomson displacement process, was introduced 



recently at Waltham Abbey. The nitration is effected in 
shallow circular earthenware pans ; when it is finished, 
water is run slowly into earthenware plates placed on top 
of the cotton, and a cock at the bottom of the pan is 
opened for the waste acid to run out at the same rate as 
the water runs on. The water removes the acid from the 
gun-cotton which is ready for boiling. This process has 
many advantages over the others. The paper describes 
fully all the operations in the manufacture of gun-cotton. 



THE RONTGEN SOCIETY. 

At the February meeting of this Society Dr. A. H. Pirie 
initiated a Discussion upon the question of the Transport 
of Ions. He said that the first to use ionic medication in 
this country was Benjamin Ward Richardson, but that it 
was only within the last ten years that the method had 
become popular in the treatment of certain diseases. The 
possible modes of conduction of electricity had been divided 
by Sir Oliver Lodge into the birdseed method, the bullet 
method, and the fire-bucket method. In the case of the 
introduction of ions into the human tissues, the first of 
these methods was the one which had to be considered. 
As a bird carried a seed with it and only dropped it when 
it had reached its destination, so an ion carried its electric 
charge — the smallest known portion of electricity — and 
dropped it when it reached an electrode. Chemical, toxic, 
antiseptic, and medicinal actions of electrolytic substances 
were almost exclusively ionic in nature. Toxic and 
pharmacological actions depended essentially on ionic 
groups, and it was much more important therapeutically 
to consider the ionic group than the atomic or molecular. 
As an example, he took phosphides and phosphates. The 
first were toxic, the second were not. Phosphides, though 
united to cations which had different actions, all possessed 
the same toxic and therapeutic effects. The phosphorus 
ion was all important in the phosphides. The phosphate 
molecule contained phosphorus in the same proportion 
as did the phosphide, but the phosphorus in the phosphate 
was locked up in the complex ion, P04 = , the properties of 
which were quite different from the phosphorous ion of the 
phosphides. The same could be said of sulphates and 
sulphides, and, in general, of all ions. When a current 
passed through the human body there was an exchange of 
ions between the surfaces of contact of dissimilar chemical 
compounds. The anions in the depth of the tissues moved 
towards the positive pole, and the cations moved towards 
the negative pole, and there was thus a change in the 
chemical composition of the deep tissues of the body. 
After demonstrating the manner in which different ions 
entered the skin. Dr. Pirie said that the chief disadvantage 
OS using ions in medicine was the fact that it was only 
possible for the patient to bear a comparatively small 
current with any degree of comfort. Usually this amounted 
to about I milliampere per square centimetre. 

In the subsequent discussion Dr. Lewis Jones read a 
letter he had recently received from Professor Leduc, of 
Nantes, the pioneer of recent ionic medication, in which 
the French investigator pointed out a curious effect he had 
lately obtained on applying an electrode of metal to a 
surface of gelatin. A film of gelatin, impregnated with 
ferrocyanide of potassium, is taken upon glass, and 
metallic electrodes, which may be of copper, iron, or zinc, 
are laid down side by side at convenient distances from 
this conducting film. A migration of ions then takes 
place, forming a precipitate of ferrocyanide of copper or 
iron or zinc, as the case may be. But, strangely enough, 
the current does not pass evenly, but shows a tendency to 
concentrate around the edges of the electrode. Thus the 
gelatin surface immediately under the electrode does not 
receive the same share of current as the portions corre- 
sponding to the edges. The ferrocyanide of copper marks 
the distance that the copper ions move during the experi 
ment, and several slides were shown in which a greenish 



84 



Meetings for the Week. 



\ Chemical News, 
; Feb. 12, 1909 



patch in the gelatin was seen to be surrounded by a ring 
of brown, due to the ferrocyanide. The gelatin immediately 
under the electrode remained green, while the parts near 
the periphery of the electrode became coloured brown. 



NOTICES OF BOOKS. 



Quantitative Experiments in General Chemistry. By John 
Tappan Stoddard. New York, London, Bombay, and 
Calcutta : Longmans, Green, and Co. 1908. 
There is a good deal to be said for the contention of the 
author of this book, that the average student of chemistry 
will get a better grasp of the principles of the science if his 
experimental work is made as quantitative as possible, and 
if, moreover, insteading of performing a very few refined 
and perfectly accurate determinations he aims rather at 
carrying out a comparatively large number of estimations 
by methods which are above all rapid, even if rough. 
Acting upon this view the author gives a rather unusual 
course of practical work, and describes a number of deter- 
minations very briefly. In addition the gas laws are 
studied, methods of determining the densities of gases are 
described, and the composition of water and air are treated. 
Some volumetric work is also included, and a specific heat 
determination. When it is mentioned that all this material 
occupies only a hundred small pages, it will be seen that 
brevity and conciseness must have been made special 
features of the descriptions, and the reviewer's attention 
would naturally be directed towards the detection of cases 
in which accuracy has been sacrificed or important details 
have been omitted. Such failings, however, are not 
apparent, and the course of practical work given in the 
book should make the student quite familiar with all the 
ordinary operations of practical chemistry and with the 
usual forms of apparatus, and at the same time lead him 
to obtain numerical data upon which to base the laws of 
chemical combination. 



Metallic Alloys; their Structure and Constitution. By 
G. H. Gulliver, B.Sc, F.R.S.E., A.M.LMech.E. 
London : Charles Griffin and Co., Ltd. 1908. 
In this book, which is based upon the lectures on alloys 
delivered in the Engineering Department of the University 
of Edinburgh, the theory of alloys is treated systematically. 
Methods of investigating them with the microscope, <S:c., 
are first described in an introductory chapter, which is of 
a more practical character than the rest of the book. The 
theory of solutions and chemical equilibrium are then 
taken up, and the case of binary alloys is considered in 
comparatively full detail. Although, of course, it has been 
found quite impossible to include accounts of all the work 
upon the formation of definite compounds in alloys which 
is issuing with such rapidity, especially from French 
laboratories, the author has done the best he can in this 
respect, choosing the brasses and bronzes for fullest treat- 
ment. The iron-carbon alloys and steels are purposely 
considered somewhat briefly, because books dealing ex- 
clusively with them are easily procurable. The phase rule 
also is treated rather shortly, no attempt being made to 
discuss the thermo-dynamical basis of the rule, for which 
the student is recommended to refer to special treatises on 
the subject. 



Text-book of Botany and Pharmacognosy . By Henry 
Kraemer, Ph.B., Ph.D. Third Edition, Philadelphia 
and London : J. B. Lippincott Company. 

In the third edition of this book many alterations have been 
made in the illustrations, the half-tone photographs being 
replaced by line drawings, in which not only the external 
morphological characters but also the internal structures 
of the specimens are made clear. Some new illustrations 



for instance, those of solanaceous drugs, have also been 
added. The third part of the book on Reagents and 
Microtechnique has been extended, and a few further 
additions have been made. The best proof of the value 
of the work for students of botany and for drug analysts 
is to be found in the fact that it has been necessary to pro- 
duce a third edition within a very short time after the 
appearance of the second, which again followed quickly on 
the first. 



MISCELLANEOUS. 

Anniversary Dinner. — It has been decided by the 
Council to arrange for a Dinner of the Fellows of the 
Chemical Society and their friends, to be held at the 
Whitehall Rooms on Thursday, March 25th, 1909, this 
being the day fixed for the Annual General Meeting. 
Further particulars will be announced shortly. 

Royal Institution. — On Thursday next, February 18, 
at 3 o'clock. Dr. Hans Gadow will begin a course of three 
lectures at the Royal Institution on " Problems of Geo- 
graphical Distribution in Mexico." The Friday Evening 
Discourse on February 19 will be delivered by Sir Henry 
Cunynghame on " Recent Advances in Means of Saving 
Life in Coal Mines." 



MEETINGS FOR THE WEEK. 

Monday, ijth.— Royal Society of Arts, 8. (Cantor Lecture). "Modern 

Methods of Artificial Illumination," by Leon Gaster. 

Tuesday, i6th.— Royal Institution, 3. " Architectural and Sculptural 

Antiquities of India," by Prof. A. A. Macdonell. 
Wednesday, 17th. — Royal Society of Arts, 8. " The Commercial Re- 
lations of France and Great Britain," by Mons. 
Yves Guyot. 

Microscopical, 8. "On a German Silver Powell 

Portable Microscope made in 1^50," by 

A. A. C. E. Merlin. "The ' Red Snow' Plant, 

Sphaereila nivalis," by G. S. West. 

Thursday, i8th.— Royal Institution, 3. " Problems of Geographical 

Distribution in Mexico," by Hans Gadow, F.R.S. 

Chemical, 8.30. " A Study of some Asymmetric 

Compounds," by F. S. Kipping. " Decomposition 
and Sublimation of Ammonium Nitrite under 
Heat," by P. C. Ray. " Estimation of Hydroxyl 
Derivatives in Mixtures of Organic Compounds" 
and " Simple Method for Determining the Chemi- 
cal Affinity of Organic Substances," by H. Hib- 
bert. " Isolation of the Aromatic Sulphinic Acids," 
by J. Thomas. "Analytical Investigation of Zir- 
conium Metal" and "Chlorine Generated by 
Potassium Permanganate, its Preparation and 
Purity," by E. Wedekind and S. Judd Lewis. 
Friday, 19th. — Royal Institution, g. " Recent Advances in Means of 
Saving Life in Coal Mines," by Sir Henry Cunyng- 
hame, K.C.B. 
Saturday, 20th. -Royal Institution, 3. "Chamber Music," Sir 
Alexander C. Mackenzie. (With the kind assist- 
ance of the Hans Wessely Quartette). 



METROPOLITAN BOROUGH of DEPTFORD. 



APPOINTMENT OF PUBLIC ANALYST. 
'"Phe Council of the above Borough invites 

-^ applications for the position of PUBLIC ANALYST for the 
Borough from gentlemen possessing the necessary qualifications and 
able to furnish such proof of competency as may from time to time be 
required by the Local Government Board. 

The appointment will be for twelve months from March 31st, igog, 
and will be subiect to the approval of the Local Government Board. 

The fee to be paid for each analysis will be at the rate of Ten 
Shillings per sample, which is to include the provision of the necessary 
laboratory, apparatus, and appliances. 

Not less than 300 samples will be submitted during the year. 

Applications, accompanied by copies of not more than three recent 
testimonials, and giving particulars of Certificates and Diplomas 
possessed by the applicant, must be made upon forms to be obtained 
at the Town Hall, New Cross Road, S.E., and must be returned to the 
undersigned not later than Saturday, FtuRUARV 27th, 1909. 

Canvassing members of the Council, either directly or indirectly, 
will disqualify candidates. 

(Signed) VIVIAN ORCHARD, Town Clerk. 

Town Hall, New Cross Road, S.E., 
Febriiary nth, 1909. 



Chemical News, 
Feb. 19, 1909 



Scandium. 



THE CHEMICAL NEWS 



Vol XCIX., No. 2569. 



SCANDIUM.* 

Part I. — The Separation of Scandium from 
Wolframite from Zinnwald. 

By R. J. MEYER. 

Historical. 
In the year 1879 Nilson {Ber., xii., 550, 554, March 22, 
1879), who was preparing pure ytterbium, discovered by 
Marignac, by the fractional melting of the nitrates of the 
earths from gadolinite and euxenite, discovered a new 
earth which was present in small quantities in the ytterbium 
fractions. It was distinguished from the ytterbium earths 
by the readiness with which its nitrate decomposed on 
being heated — it was thus more electro-negative than they 
—and by its very low molecular weight. Thalen's examina- 
tion of the spark spectrum in the optical region showed 
that a new element was present. Nilson named it 
scandium. However, he only succeeded in obtaining 
about 0-3 grm. of a product in which ytterbium still pre- 
ponderated ; its atomic weight was about go. Some weeks 
later, Cleve (Bull. Soc. Chim., [2|,xxxi., 486, May 13, 
1879) announced that he also had succeeded in isolating 
scandium, both from gadolinite and from yttrotitanite 
(keilhauite). The yields first given by him of 0-02 to 0-04 
per cent relate, however, to an oxide, which Nilson after- 
wards calculated to contain only about 30 per cent of 
scandium earth, while the actual amount present in the 
minerals worked up by Cleve was estimated to be about 
0-002 to 0-003 per cent. Subsequently, Cleve, working 
with richer raw material, succeeded in obtaining a rather 
larger amount of the earth in an approximately pure state ; 
he determined its atomic weight with some degree of 
accuracy, and by preparing some of its compounds he 
was able to give some description, if incomplete, of the 
properties of the element. In two determinations he 
obtainedfor the atomic weight Sc = 44-9i and 45'i2. This 
discovery was regarded as the more striking because 
Mendeleeff {Lieb. Ann., Suppl., viii., 133) had foretold the 
existence and the properties of a new element of atomic 
weight 44, ekaboron, basing the prophecy on his law of 
periodicity, and by the fulfilment of the prediction by the 
experimental discovery the position of scandium in the 
Periodic Table was settled once for all. In i88o Nilson 
published what were for the time being the final statements 
on the subject [Ber., xiii., 1439, June 12, 1880; Ofvers af 
K. Svenska Vet. Akad. Forhandl., 1880, No. VI.). He 
had succeeded in isolating from 10 kilogrms. of euxenite 
some grms. of scandium oxide of a high degree of purity ; 
he had also acquired further knowledge of its chemical 
properties, and had finally established its atomic weight by 
four determinations which gave the values 4399, 44*07, 
44"05, and 44*02. (By studying the arc spectrum Exner 
and Haschek showed that Nilson's preparations contained 
small amounts of ytterbium). The spark spectrum of this 
pure material was measured by Thal^n (Comptes Rendus, 
xci., 45). 

The investigation of scandium was then compulsorily 
abandoned for a time, and hardly any mention is made of 
it in literature during the period from 18S0 to 1907. Two 
explanations may be given for this neglect of a substance 
which had been shown by its discoverers to be highly 
interesting ; owing to its extreme rarity investigators 
could hardly hope to be rewarded by appreciably increased 
yields for the considerable outlay of time, trouble, and 

♦ Zeitschri/t Jiir Anorganische Chemie,\\., 134, November 17, 1908. 



85 

money required for the preparation even of small quantities, 
and, secondly, because searches had often been made for 
scandium without success. Thus, Urbain mentions that 
he had never come across scandium in the course of his 
successful studies, extending over years, of the yttrium 
earths of various origins (yourn. Chim. Pkys. Geneve 
1906, IV 31). In the current year Sir William Crookes 
published a preliminary communication on the occurrence 
of scandium and on the composition of a series of its com- 
pounds (Proc. Roy. Soc, Ixxx., A, p. 516, June 10, 1908). 
By the spectrographic examination of fifty-three minerals 
which almost all contained the rare earths as the basic 
chief constituent, he showed that ten of them contained 
scandium, but that only one, namely, wiikite, a Finnish 
mineral never before described, contained the surprisingly 
large proportion of 1 per cent scandium oxide, while the 
other nine contained less then ooi per cent. According 
to the provisional analysis given by Sir William Crookes, 
the composition of wiikite is very complicated. The 
negative constituents it contains are titanic, tantalic, 
niobic, and silicic acids, and the positive constituents are 
iron, yttrium earths, cerium earths, thorium, uranium, and 
1-17 per cent scandium oxide. The mineral must thus be 
allied to the members of similar composition of the group 
to which fergusonite, yttrotantalite, samarskite, polycrase, 
euxenite, &c., belong. For the present no information is 
given relating to the difficult process of isolating pure 
scandium from this mineral, nor to its distribution, but, on 
the other hand, a large number of scandium salts are 
classified according to their composition. 

Quite recently, G. Eberhard published a much more 
comprehensive account of the occurrence of scandium 
(Sitzicngsber. Kgl. Preuss.Akad. Wissensch., 1908, xxxviii., 
851). Starting from the fact that the strongest lines of 
the scandium spectrum are observed in the spectra of stars 
in the most different stages of development, he concluded 
that scandium must be universally distributed on the earth 
(the same reasoning foretells the occurrence of helium on 
the earth), and by investigating the arc spectrum of 366 
minerals and rocks he obtained the remarkable result that 
scandium in small quantities is actually one of the most 
widely distributed of the elements on the earth, and that 
by spectral methods it may be detected in almost all the 
rocks which form the earth's crust. He further showed 
that it is most frequently met with in zirconium minerals, 
beryls, titanates, niobates, and titan-niobates of the rare 
earths, in micas, and finally — and this is the most important 
result from a chemical point of view— that wolframite and 
tinstone from some places in the mountain ranges of 
Saxony and Bohemia contain scandium in such amounts 
that the extraction of the earth from these minerals would 
be profitable. Undoubtedly the disadvantage of the 
always small absolute amount of rare earths which these 
minerals contain, and which has hitherto quite escaped 
detection by chemical analysis, is outweighed by the fact 
that scandium forms the predominant constituent of the 
rare earths generally present in them, while the minerals 
worked up by Nilson and Cleve contained only traces of 
scandium distributed throughout an enormous excess of 
other earths. 

So if starting from our fundamental cosmogenetic 
theories we arrive at a practical result, it may also be fore- 
seen from purely chemical considerations that scandium is 
not to be searched for specially in the places where it has 
hitherto been supposed to exist exclusively, namely, in the 
typical minerals of the rare earths, for the chemical 
character of the element, so far as it is known at present, 
deviates considerably from the typical nature of the rare 
earths in the narrower sense. Such a difference may be 
confidently expected owing to the low atomic weight; i.e., 
the position it occupies in the Periodic System, Whereas 
in the case of the cerium and yttrium earths we are dealing 
with comparatively strongly positive elements, as we pass 
from the ytterbium earths, the most negative members of 
the yttrium earths, to scandium, we observe an unusually 
decided decrease of basicity. This is shown both by the 



86 



Scandium. 



I C»Eii<icAL News, 
I Feb. 19, 1909 



ready solubility of the hydroxide and the salts in soda, 
and by the strongly developed tendency, connected with 
it, of undergoing hydrolysis and forming complexes. In 
this respect, scandium is much more like tetravalent 
thorium, aluminium, or beryllium than the rare earths. 
Moreover, in other respects, scandium differs from the 
series of the cerite and yttrium earths. While in the latter 
the solubility of the oxalates in acids increases with the 
increasing positive character, the solubility of scandium 
oxalate far exceeds that of the oxalates of the other earths. 
Scandium is also distinguished from the other rare earths 
by the fact that the sulphate crystallises with six molecules 
of water, a type which is otherwise hardly known amongst 
the sulphates of the rare earths, and that it is easily soluble 
in water. 

(Note. — Brauner appropriately calls scandium " an 
extrapolation " in the series of the elements of the rare 
earths (Abegg, "Handb. d. Anorg. Chem.," III., i., p. 340). 
If it is included amongst the cerium earths because of the 
difficulty with which its potassium double sulphate dis- 
solves, then it occupies the same isolated position in this 
sub-group as yttrium in the group of the yttrium earths). 

The results obtained by Eberhard do not enable us to 
detect an evident connection between the chemical nature 
of scandium and its occurrence on account of its very wide 
distribution, but it is clear that the occurrence of the element 
is not restricted to the typical minerals of the rare earths. 
As regards the occurrence in wolframite and tinstone from 
the Ore Mountains, this localisation in a small region 
shows that specific geological causes are responsible for 
the concentration of the element in this place. 

For the investigation now to be described of the quanti- 
tative isolation of scandium from wolframite, it seemed 
desirable to acquire a knowledge of the most important 
reactions of the element from personal observation. I owe 
hearty thanks to Prof. Dr. W. Nernst, who enabled me to 
do so by sending me one of Cleve's original preparations. 
I should not have been able to carry through this task with 
any hope of success if the best procedure had not been 
pointed out by the spectrographic examination of almost 
all the precipitates and filtrates which were obtained in the 
numerous attempts to find the most advantageous method. 
These tedious examinations were very kindly performed 
by Prof. Dr. G. Eberhard, of the Astrophysical Observatory, 
in Potsdam. He used for the purpose a grating spectro- 
graph belonging to the observatory {cf, G. Eberhard, loc. 
cit.). I wish to express to him also my hearty thanks for 
this valuable aid, which was indispensable for the success 
of the work. 

Preliminary Experiments. 

For the preliminary experiments I obtained from the 
Department for the sale of minerals of the Kgl. Sachs. 
Bergakademie, in Freiberg, wolframite from Zinnwald, 
near Attenberg, in the Saxony Ore Mountains ; it consisted 
of large pure pieces containing only very little matrix. 
The quantitative analysis of the mineral will be published 
in a later communication. It was first necessary to 
ascertain into which part the scandium would go when the 
mineral was opened up with soda. A priori it was to be 
expected that when the melt was extracted with water the 
scandium would go over into the alkaline solution with the 
tungstic acid, since it forms soluble double carbonates. 
However, when the oxides which remained undissolved on 
extraction with water were subjected to spectroscopic 
examination, it was found that they contained all the 
scandium, while the alkaline filtrate, from which the 
tungstic acid was separated in the usual way, contained 
none at all. This behaviour was explained by an observa- 
tion made later, that solutions of scandium salts in soda, 
if they are diluted with water and boiled, undergo a 
complete hydrolytic dissociation with separation of the 
carbonate. The assumption which was first made, that 
wolframite possibly contains scandium in the form of a 
fluoride insoluble in alkali, was not confirmed, for the 



examination for fluorine gave a negative result. The 
examination for fluorine was performed by K. Daniel's 
very sensitive method {Zeit. Anorg. Chem., 1904, xxxviii., 
257). Thus the working up experiments could now be 
restricted to the residue consisting chiefly of iron and 
manganese oxide. 

Raw Material. 
In the first experiments the methods of isolating the 
scandium quantitatively were worked out. For this 
purpose the above mentioned very pure wolframite was 
used ; it was finely powdered, and portions of 100 grms. 
were heated in Chamotte crucibles in a Perrot's furnace 
with 220 to 230 grms. of free soda, some potassium nitrate 
being added. The melt was washed with boiling water 
containing some alcohol, and the brown mixture of oxides 
left was dissolved in concentrated hydrochloric acid, after 
having been washed. The silica which separated was 
removed, the solution was evaporated to dryness on the 
water-bath, and the residue taken up with water. More 
recently, after the completion of the preliminary experi- 
ments, a manufactory which is engaged in the preparation 
of metallic tungsten placed at my disposal large quantities 
of oxide residues from Zinnwald wolframite. These 
residues from the manufacture of tungsten provide an 
excellent and cheap raw material for the preparation of 
scandium, but they can only be used for this purpose if 
they have been obtained from good ore (" Stuferz "), while 
the so-called " Setz " or " Schlicherz " (small ore or slick), 
which contains large quantities of gangue, gives a less 
productive oxide residue. Even the best ore often con- 
tains some matrix, and the residues yield large quantities 
of silica when they are dissolved in hydrochloric acid. It 
was usually found that 20 per cent by weight of this 
"technical wolframite oxides" is insoluble, a circumstance 
which must be taken into consideration in calculating the 
yield. I must again point out that only the wolframite 
from some places in the Saxon and Bohemian Ore 
Mountains is worth working up for scandium. Eberhard 
has proved spectrographically that specimens from other 
places only contain traces of it. I obtained the same 
result by working up the residues of an Australian 
wolframite, which gave a yield of only 0015 per cent of 
rare earths, while the normal yield of residues from 
Zinnwald wolframite amounts to 0*30 to 0*33 per cent. 

Methods of Separation. 
I will now describe the methods which lead to the 
separation and preparation in the pure state of scandium 
from the solution of wolframite oxides. The chief aim of 
these experiments was to obtain a " quantitative " isolation, 
which could only be attained if each precipitation was 
controlled by means of spectrographic examination. 

A. — Concentration by Precipitation with Oxalic Acid. 

It is well known that the group of the rare earths is 
usually totally separated from other substances, such as 
iron, manganese, calcium, &c., by precipitation with oxalic 
acid from acid solution. But it must be remembered that 
scandium oxalate, unlike the oxalates of the other rare 
earths, is very readily soluble in acids, and that it is im- 
possible to precipitate with alkali oxalates owing to the 
formation of soluble oxalate complexes. Moreover, the 
large quantities of iron which the solution contains have a 
disturbing effect on the separation. When oxalic acid is 
added to concentrated ferric solutions, the ferric ion, Fe-", 
yields a complex ferric-oxalate ion, as shown by the colour 
change to green. Thus the solution uses up oxalic acid 
until all the iron is bound in the complex. At the same 
time the concentration of the H-ions is continually raised. 
When to the neutral or feebly acid solution of the 
wolframite oxides a certain quantity of oxalic acid is 
added, at first no precipitate is formed, but when the solu- 
tion is warmed or it has stood for a long time, a precipitate 
appears owing to the formation of ferrous ions by auto- 
reduction, the latter being gradually separated as difficultly 



Chbuical News, 
Feb. ig, 1909 



Method for Determining Vapour -densities. 



soluble ferrous oxalate. The scandium is, of course, con- 
centrated in these precipitations of ferrous oxalate, as 
spectrographic examination shows, but it is not possible to 
concentrate the whole amount in one fraction by this 
method ; nor can this be effected if the iron solution is first 
reduced with sulphurous acid and the ferrous oxalate is 
then precipitated in fractions by successive additions of 
oxalic acid. An almost complete precipitation of the rare 
earths may be accomplished if to the nearly neutral ferric 
solution a sufficient excess of oxalic acid is added to bind 
all the iron in the solution in an oxalate complex ; then 
further addition of the acid precipitates scandium oxalate. 
The weight of oxalic acid necessary is nearly the same as 
the weight of oxides used. Since, owing to the solubility 
of scandium oxalate in acids, the iron solution must be as 
nearly as possible neutral before the precipitation, and the 
complete evaporation of solutions, from which large 
quantities of iron chloride separate, is accompanied by 
difficulties when considerable quantities of wolframite 
oxides had to be worked up, an approximately saturated 
solution was first prepared. For this purpose i kilogrm. of 
the oxides was boiled with 2-5 litres of crude hydrochloric 
acid (sp. gr. i*i§) until no more chlorine was evolved. The 
solution was then diluted a little, and the dark red iron 
solution was drawn off from the deposit of silica. The 
latter was boiled with water and washed, the filtrate being 
added to the first filtrate. (This insoluble residue per- 
sistently retains soluble constituents ; it should be quite 
grey after washing). This solution, the volume of which 
was about 3 litres, was neutralised by the addition of con- 
centrated ammonia (25 per cent) drop by drop, the whole 
being vigorously stirred until a permanent precipitate was 
formed. (For this purpose about 200 cc. NH3 are neces- 
sary for every kilogrm. of oxide used) . Then a hot saturated 
solution of 800 grms. of oxalic acid was added. After 
standing for twenty-four hours a greyish yellow or yellow 
precipitate containing some crystals of oxalic acid separated. 
This consisted of a mixture of manganese, calcium, lead, 
and iron oxalates, as well as the oxalates of the rare earths 
which are completely precipitated in these circumstances. 
After washing and igniting the oxalates a mixture of oxides, 
coloured black by manganese dioxide, remained, its weight 
being 4 to 5 per cent of that of the oxides used. By this 
method a very considerable concentration of the earths is 
effected. It is not practicable to prepare them in the pure 
state from this mixture, because of the impossibility of 
completely removing the manganese. The lead was 
removed with sulphuretted hydrogen, the calcium with 
ammonia, and the hydroxides were dissolved in hydrochloric 
acid. (Spectrographic examination shows that the lead 
sulphide always contains scandium). Then the neutral 
solution of the chlorides was again precipitated with an 
excess of oxalic acid. But in this process the manganese 
always follows the earths, and cannot be completely re- 
moved by repeated precipitations of oxalate from faintly 
acid solution. (I have often observed in other cases the 
pertinacity with which manganese follows the rare earths ; 
for instance, it is exceedingly difficult to remove manganese 
completely from manganese double nitrate fractions of the 
cerium earths). However, after many unsuccessful 
experiments it was found that the separation could easily 
be effected by precipitating the earths with hydrofluoric 
acid. 

(To be continued). 



87 



South-Western Polytechnic Institute, Chelsea. — 
Professor Henry A. Miers, D.Sc, F.R.S., Principal of the 
University of London, presents prizes and certificates to 
Students of Evening Classes and Day College on March 
I2th, at 8 p.m. 

Aqueous Solutions of Pyridine. — E. Baud. — Aqueous 
solutions of pyridine contain at least two hydrates, the 
one containing 2H2O and the other 6H2O to one molecule 
of pyridine. At the ordinary temperature these hydrates 
are dissociated in their solutions. The hydrate containing 
|he most water is the least stable. — C. R., cxlyiii., No. 2. 



A SIMPLE METHOD FOR DETERMINING 

VAPOUR- DENSITIES. 

By PHILIP BLACKMAN. 

The following method for obtaining the necessary formula 
for the calculation of vapour-densities will be found much 
more satisfactory than (it also differs in the latter part 
from) the incomplete one given in the Chemical News, 
1907, xcvi., 223, or the fragmentary one given in the 
Zeit. Phys. Chem., 1908, Ixiii., 49, 50, 636, especially with 
regard to the legality of considering L, Lc, /, and h as 
linear quantities (compare also jfourn. Phys. Chem., looS, 
xii., 662, 668). 

Let — 

w = Lhe weight of the substance experimented on, 
^1° = the atmospheric temperature, 
L = the length of the air-thread in the manometer 
at ti° (before sealing the bulb), 
Lc = the length of the air-thread in the manometer 
at ti"^ (after the bulb is sealed), 
/ = the length of the air-thread in the manometer 

at (2°, 
V = the volume of the bulb, 
p = the atmospheric pressure, 
d — the vapour-density required. 

<2° = the temperature to which the bulb is heated, 
H, A = the volumes of the air-thread at /i° and /a' 
respectively between the open end of the 
manometer and the mercury thread, 
a = the area of the cross-section of the capillary 
bore. 

The initial internal pressure at ti° — 

= pLalLca=\fi (i) ; 

the final total pressure at ^2° — 

= i' U (1(273 + tj) ... 

la{273fh) ^'' 

the pressure of the air only in the bulb at ^2° — - 

^ ;;/(¥+ H)(273 + /2) 

(V + h){273 + h) ' ■ ' ' 

The volume of the vapour at 0° and 760 mm. is 11 160 wjd 
(assuming that at 0° and 760 mm. pressure i grm. of 
hydrogen occupies iii6o cc.) ; at ^2° the volume is V+A ; 
consequently its pressure is — 



(3). 



1 1 160 X 760 w (273 -f- ^2) 



(4): 



273 d(V+h) 

but (2) =(3) + (4), from which, on simplification, — 
._ 31068 w the (273 + ti) 

"#L,v+»)(u-,:^) 

Generally H and h are so small compared with V that 
they may be neglected, and use be made of the far simpler 
and almost inappreciably less accurate formula — 

31068 w I Lc (273 -»- ti) 



pLW{Lc-l) 

It is interesting to observe that the less complicated 
formula may be obtained in the following simple and in- 
structive manner : — 

The vaporised substance causes the manometer air- 
thread to contract by the amount Lc — /, which corre- 
sponds to a comparative pressure (Lc - /)//, or an actual 
pressure — since the initial pressure is 1^, see (i) above, and 
the temperature has altered from ti° to /2° — 

^(U-l)(273 + t2) 
M273 + M 



88 



New Development in Gas Heating. 



Chemical News, 
Feb. 19, 1909 



which, however, must be equal to — 

III6OX76OW (273 +<2) 

273 d (VTli) 
— see (4) above. Therefore, after simplifying, — 
d= 3^068 w I Lc ^273 + ti) 
pL(Y + h)(Lc-L) 

In calculating the percentage composition of a binary 
mixture it may occasionally be found more convenient to 
use the equation — 

d2'Wi + di{ioo — Wi) = loodidsld 
than — 



d2Wi+di{ioo - Wi) 

ackney Technical Institute, 
London, N.E. 



iood'i</2/.LV(Lc - /) 
31068 w Ihc (273 + ti) 



A CONVENIENT FUNNEL SUPPORT. 
By L. D. HAVENHILL. 

It frequently happens when a chemist has to make a brge 
number of slowfiltrations that he finds himself embarrassed 
by the lack of a sufficient number of funnel supports. The 
writer recently overcame an experience of this kind by 




Fig. I. 



Fig. 2. 



mprovising a simple and inexpensive holder, vvhich has 
since proven so convenient, especially for holding small 
unnels, that he desires to bring it to the notice of his fellow 




Fig. 3. 

chemists and others who may perhaps soitietimes find use 
for it. 



For supporting funnels up to 10 cm. in diameter, take a 
piece of No. 18 copper wire about 10 cm. long and bend it 
around the stem of the funnel until it assumes the form of 
a key (Fig. i). Then open out the arms of this key and 
bend the ends downwards and inward, so that they will 
hook over the top of the beaker or other receiving vessel 
(Fig. 2). The holder rests on the top of the beaker at the 
points a a. The funnel is supported by the loop c, which 
partially encircles the stem and holds it against the inner 
side of the beaker, as shown in Fig. 3. 

A sufficient length of wire should he used in forming the 
hooks dd, so that the support cannot fall into the receiving 
vessel when the funnel is withdrawn from it. The length 
and size of the wire, as well as the size of the loop formed 
around the stem of the funnel, can be varied to suit the size 
of the funnel as well as the kind of receiving vessel used. — 
yournal oj the American Chemical Society, xxxi., No. i. 



A NEW DEVELOPMENT IN GAS HEATING. 

The Bunsen burner, though it has proved its real worth 
through many decades and is conceived along truly 
scientific lines, falls short of our ideal. 

Some few years ago a French chemical engineer, M. 
Meker, determined to design a burner which should closely 
approach the ideal, and after many systematic experiments 
and much painstaking and persevering work, his efforts 
were rewarded with success. A sectional view of the final 
type adopted is shown in Fig. i. 




Fig. I. — Ordinary Meker Burner. 

It will be seen that the gas enters at the bottom of the 
burner in the usual way, but the air inlet holes are much 
larger than usual, and the mixing chamber or chimney is 
of a special shape somewhat resembling an injector. By 
this means the gas and air are caused to thoroughly mix 
in the proportions necessary for complete combustion, and 
the mixture ascends at a great speed. The essential 
feature of the burner is, however, what M. Meker calls 
the " cloissonnage" fitted at the mouth of the burner to 
prevent " back-firing." This is a deep grid built up of 
thin strips of nickel, and is in appearance somewhat like a 
honeycomb, except that for simplicity in construction the 
cells are of square section. This nickel grid completely 



Chemical News, 
Feb. ig, 1909 



Pure Solution of Effective Principle of Suprarenal Gland. 



89 



covers the mouth of the burner, as will be seen by the 
plan in Fig. i, and each of the square channels formed 
measure 2 millimetres square and is 10 millimetres deep. 
The fact that this grid is so successful in preventing the 
flame from gaining entrance to the highly explosive mix- 
ture in the mixing chamber or chimney, is because a flame 
has great difficulty in travelling in a direction opposite to 
the movement of the gaseous mixture which gives rise to 
it, if in this inverse direction it encounters a very large 
cooling surface. Since the grid is of such an open mesh, 
it has practically no throttling action on the mixture, and 
being made of nickel it has a great power of resisting 
oxidation or chemical action, and therefore a long life. 
Also it acts to some extent as a regenerator of heat, since 
the heat which is absorbed by the upper surface in contact 
with the flame is conducted downwards and given up to 
the cold gaseous mixture as it rises up the channels. The 
grid is thus always kept at a comparatively low tempera- 
ture, so that if, accidentally, molten matter falls on it, it 
immediately solidifies without penetrating the interior and 
can be readily removed after cooling. 

The flame given by the Meker burner is quite novel in 
appearance and unique in its characteristics. At the top 



Plan of Grid B 




■■■■" ■■■lUT-'UV^ vb9 



Fig. 2. — Meker Burner for Use with an Air Blast. 



of each channel in the grid a small cone about 2 mm. high 
is visible, but above this is a solid cylinder of flame in- 
tensely hot. Experiments with a thermo-couple have 
shown that the temperature at all points in the flame is 
practically the same, and is higher than the highest tem- 
perature found in the ordinary Bunsen flame. If a thick 
copper wire be held in the flame it is quickly melted. 

Special muffle and tube furnaces have also been made, 
in which temperatures up to 1200° C. can be obtained, 
also without any air-blast. 

Such striking results at once suggest the question as to 
what may be expected of this burner when it is intended 
to use an air-blast. The burner so designed is illustrated 
in Fig. 2. 

It will be seen that the mixing chamber and " cloisson- 
nage " remain the same, but the air-blast itself enters by 
the tube marked " Air " and escapes into the mixing chamber 
through six small holes arranged concentrically around the 
gas injector. 

These burners and furnaces have up to the present been 
very little known in England, but we understand that, 



under the new Patent Act, they will in future be manu- 
factured here by the Cambridge Scientific Instrument 
Company, Ltd., of Cambridge, who have acquired the 
sole rights for Great Britain and the Colonies. 



METHOD OF PRODUCING PURE SOLUTION 

OF THE EFFECTIVE PRINCIPLE OF THE 

SUPRARENAL GLAND OR PARANEPHROS. 

By Dr. MORITZ MAX FREUND. 

This patented invention relates to a method of producing 
a pure solution of the effective substance of the suprarenel 
gland or paranephros. It is known that solutions of the 
effective substance of the suprarenal gland or paranephros, 
C9H13NO3, are very easily oxidised, with accompanying 
discoloration on coming into contact with air. This 
applies both to the solutions of the separated substance as 
well as to raw aqueous extracts of the organ. It has 
therefore been proposed already to avoid or restrict the 
oxidation by carrying out the whole operation of extraction 
under air seal ; i.e., excluding the air, or by working in an 
atmosphere of hydrogen. The effect aimed at, however, 
could only be obtained to a very imperfect degree or with 
great difficulty. 

I have found that known processes of electroljrtic 
reduction, which effect a rapid and energetic reduction, may 
be used with advantage for this purpose. I have found 
that this method or process is applicable both to solutions 
of the separated substance as well as to aqueous extracts 
of the suprarenal gland or paranephros, as in both cases 
no progressive decomposition or change in the substance 
itself takes place. 

This invention consists in preparing a pure solution of 
the effective principle of the suprarenal gland or para- 
nephros by electrolytic reduction of impure solutions of the 
substance or its salts. 

By this process solutions are obtained which remain for 
a long time undecomposed, and, further, the base when 
isolated is both white and analytically pure. 

Solutions which contain 3 to 5 per cent of the effective 
substance C9Hi3N03 are used for reduction. For example, 
an extract of one-tenth kilogrm. fresh gland is prepared, 
the bulk being preferably not greater than 500 cc. This 
solution is filtered, and then electrolytically reduced, using 
a platinum cathode, a carbon anode, and a porous cell as 
a diaphragm. The solution is rendered slightly acid, the 
duration of the action being preferably from one to two 
hours. Solutions of salts of the isolated substance may be 
similarly subjected to electrolytic reduction. 

Thus a solution of the hydrochlorate of the isolated sub- 
stance (say, 20 grms. in 600 cc.) may be subjected to an 
electrolytic reduction by cathodic hydrogen for one hour 
as in the above process. 



Nitrohydroquinonedimethylether and the Theory 
of Solutions. — Hugo Kauffmann. — Nitrohydroquinone- 
dimethylether gives colourless or yellow solutions with 
different solvents. The investigation of this phenomenon 
shows that change of fluorescence occurs usually without 
any alteration in constitution, and thus it is not correct to 
ascribe it to constitution. Even with unalterable con- 
stitution there is in the molecule an element capable of 
being altered ; this may be represented graphically by a 
" condition " formula. The constitutional formulae are ideal 
extremes which the condition formulae more or less 
approach. The conditions may be deduced from variations 
in the fluorescence band. Non-dissociating solvents are 
not indifferent, and allow an approximation to the ideal 
condition to be attained. The assumption that two modi- 
fications of nitrohydroquinonedimethylether exist is un- 
necessary, the change of colour being due to condition 
changes. — Berichte, xli., No. 18. 



go 



Determination oj Rate of Chemical Change. 



\ Chemical News, 
1 Feb. 19, igog 



PROCEEDINGS OF SOCIETIES. 

CHEMICAL SOCIETY. 
Ordinary Meeting, February ^th, 1909. 

Sir William Ramsay, K.C.B., F.R.S., President, 
in the Chair. 

Mr. F. Williams was formally admitted a Fellow of the 
Society. 

Certificates were read for the first time in favour of 
Messrs. Howard Alfred Caulkin, B.Sc, Oaklands, Solihull, 
Warwickshire; John Henry Chew, 46, Lytham Road, 
Blackpool ; George Clarke, Cawnpore, U.P., India ; 
George Stanley Cooper, Heaton House, Cleckheaton, 
Yorks. ; William Fowler, 3, Cranbrook Road, Victoria 
Docks, E. ; Egerton Hargreaves, M.Sc, " Arthog," 
Garner's Lane, Davenport; Reginald Hopkinson, B.Sc, 
Brimington House, Brimington ; Floyd J. Metzger, 
Columbia University, New York City, U.S.A. ; Oswald 
John Dalgatty Thomas, 65, Clarendon Gardens, Ilford ; 
Vernon James Tilley, " Linthorpe," Becmead Avenue, 
Streatham, S.W. ; Charles William Truelove, B.Sc, 17, 
Tylney Road, Forest Gate, E. ; Robert William Wilson, 
2, Parade, Aldersbrook Road, Manor Park, E. 

Of the following papers, those marked * were read : — 
*22. " The Mechanism of the Reduction of Nitroanilines 
and Nitrophenols." By Bernhard Flurscheim. 

Fliirscheim and Simon have shown recently that 2 : 4- 
dinitrodiphenylamine, on reduction by stannous chloride, 
only yields the amine under conditions which cause the 
azoxy-derivative to be formed in the case of all the other 
diniiro compounds examined. Similar observations in 
alkaline solutions had led Elbs to assume the following 
changes during the reduction of 0- and />-nitroaniline and 
phenols : — 

^6"'^<NH0H ^^ ^&^4=:iiu ^ *-6"4<.NH2' 
According to the views on substitution in aromatic com- 
pounds put forward by the present author, it seemed 
possible that, condensation to the azoxy-derivative being 
due to the residual affinity of the teivalent nitrogen in the 
hydroxylamine and nitroso-compounds, partial saturation 
of that residual affinity through the influence of an ortho- 
or para-amino- or hydroxy! group might prevent such 
condensation. 

To decide this question, the behaviour of 2 : 4-dinitrodi- 
phenylmelhylamine was examined intramolecular change 
being here excluded. It was found that, in this case also, 
no azoxy-compound, but only the amine, is formed. Ex- 
perimental evidence therefore favours the second of the 
above hypotheses. 

*23. " The Relation between the Strength of Acids and 
Bases and the Quantitative Distribution 0/ Affinity in the 
Molecule." By Bernard Flurscheim. 

It has been frequently observed that introduction of 
acidic or basic radicles into the molecule of an acid does 
not necessarily affect the dissociation constant in the 
expected sense, but often in the opposite direction. The 
author suggests the following hypothesis in explanation of 
this: — The dissociation constant of an acid is inversely 
proportional to the strength of the bond between the 
acidic radicle and hydrogen, and directly proportional to 
the strength of the linking between the acidic radicle and 
the negative electron. Tlie latter depends on the more or 
less negative nature of the acidic radicle ; the former, 
however, is chiefly a function of the amount of affinity 
which the atom to which hydrogen is linked can place at 
the hydrogen's disposal. This amount is variable, and its 
order of magnitude can in each particular case be foreseen 
by the application of general views previously advanced by 
the author. 

Similarly, quaternary ammonium hydroxides and I 



analogous derivatives of oxygen, sulphur, iodine, &c., 
even when negatively substituted, may be strong 
electrolytes, because quinquivalent nitrogen can only 
weakly attract the hydroxyl group. Lastly, the salts of 
amines, &c., with acids are hydrolysed more readily when 
the nitrogen is linked to unsaturated atoms which absorb 
much of its affinity. A consideration of many affinity 
constants, hitherto thought abnormal, confirms these views, 
which have also been experimentally supported by the dis- 
covery that, when the basic group -NMePh is introduced 
in the ortho-position with respect to the amino-group of 
»/-nitroaniline, the basicity of the latter is very considerably 
reduced. 

*24. " Note on the Determination of the Rate of Chemical 
Change by Measurement of the Gases Evolved." By 
Francis Edward Everard Lamplough. 

In a criticism of the author's work on this subject, J. C. 
Cain and F. Nicoll (Proc, 1908, xxiv., 282) have con- 
tended that the solutions of dlazobenzene chloride, the 
rate of decomposition of which was being determined by 
them from the rate of evolution of nitrogen, did not 
become supersaturated by the gas, and that no error was 
thereby introduced into their results. 

With regard to the statements of Cain and Nicoll, it is 
manifest that their treatment of the solution (shaking, &c.) 
before measurement could not possibly prevent super- 
saturation occurring whilst measurement was taking place. 
Secondly, the ultimate evolution of the calculated volume 
of gas from the solution is merely evidence that the con- 
dition of supersaturation is only a temporary one. This 
would be expected of a metastable state, and is fully 
shown to be the case from the author's experiments. 

A very simple direct experiment is, however, the most 
convincing proof that their reasoning is inadmissible. If a 
solution of dlazobenzene chloride, prepared in the usual 
manner and rapidly heated with or without shaking, say, 
to 50°, is allowed to stand for ten or fifteen minutes, and the 
flask then gently revolved so as to set the liquid in fairly 
rapid rotation, a copious effervescence will at once be seen 
to result. The effect is still more clearly shown if the flask 
is connected to a pneumatic trough, in which case the 
liquid may be well agitated by shaking. 

Experiments were made by the author which showed 
that under conditions of efficient stirring no acceleration of 
the reaction was produced by " colloidal " platinum. This 
is not surprising in view of the immediate precipitation of 
the metal from the colloidal state in the presence of the 
strong electrolytes contained in the solution. 

In throwing doubt on the measurement of temperature, 
Cain and Nicoll appear entirely to have overlooked the 
experiment (Proc. Canib. Phil. Soc, 1908, xiv., 590) by 
which it is proved that, throughout the time of measure- 
ment, the temperature of the reacting liquid did not differ 
more than 01° from that of the water-bath. A few words 
of a sentence from the author's paper are quoted apart 
from the context by Cain and Nicoll, so that they produce 
an entirely incorrect impression as to the actual procedure. 

Finally, no suggestion of errors in temperature measure- 
ments could possibly dispose of the obvious conclusions 
from the comparative experiments performed with and 
without stirring at the same temperature and in the presence 
of the same platinum stirrer. In the experiments with 
agitation of the solution, the gas was at first evolved 
with high velocity, and this rate gradually diminished, 
strictly following the unimolecular law. In those without 
agitation, the rate of evolution was at first slow, gradually 
increased to a maximum value, and then diminished ; if 
the stirrer was set in motion at any time in such an experi- 
ment, the immediate evolution of the large quantity of 
stored-up gas indicated a degree of supersaturation up to 
100 times the volume normally dissolved. Again, in the 
experiments with stirring, the values of the velocity con- 
stant rom first to last showed only very slight and 
irregularly-distributed differences from the mean value ; in 
the experiments without stirring, and in those of Cain ^n^ 



Chemical News, 1 
Feb. 19, 1909 I 



Constituents of the Bark of Prunus serotina 



91 



Nicoll, at best only a limited range from the middle of the 
experiment could be selected over which the calculated 
values of the " constant " (much lower than those of the 
experiments with stirring) might be plausibly uniform. 

Discussion. 

Dr. Veley remarked, with reference to the author's 
statement as to the rate of decomposition of oxalic by 
sulphuric acid, that it appeared unreasonable, if not 
romantic, to criticise work which he, the speaker, had 
never done, and conclusions at which he had never 
arrived. 

From calculations made in a number of cases in which a 
gas is evolved from a solution by a process of chemical 
change, it appeared that the author had very greatly over- 
estimated the supersaturation value as at 100, or even 
more ; it probably did not exceed 8 to 12, according to the 
nature of the gas and conditions of experiment. 

Mr. Lamplough, in reply, pointed out that Euler per- 
formed his one comparison experiment with and without 
stirring at 25°. At this temperature the velocity of the 
reaction would be 100 times less, and the solubility of 
nrtrogen only twice greater, than at the temperature of his 
(the speaker's) comparison experiment then under con- 
sideration, and a much closer agreement would therefore 
be expected. The author had hitherto confined his atten- 
tion to the benzenediazonium compounds, and these had 
been investigated at temperatures from 36'' to 67°. Mr. 
Lamplough offered apologies to Dr. Veley for the incorrect 
statement that he (Dr. Veley) had shown the decom- 
position of oxalic acid by sulphuric acid to be bimolecular. 
It should rather have been said that Dr. Veley found that 
the decomposition of formic acid by sulphuric acid was 
bimolecular, but had arrived at no conclusion from his 
experiments with oxalic acid {Phil. Trans., 1888, clxxviii,, 
280, 291). Both these actions had since been shown to be 
unimolecular, the former by the author, the latter by 
Lichty, of Heidelberg, by a titration method. He further 
pointed out that his method of determining the degree of 
supersaturation was not theoretical, but practical, and con- 
firmed his assertion as to the high degrees of super- 
saturation obtained by showing from the curves of an 
actual experiment that 37 cc. of solution at 62° held at one 
time 21 cc. of gas, which from the value o"oo6 for the 
solubility of nitrogen at 62° represented a degree of super- 
saturation of more than 90. In justification of the words 
" plausibly uniform," an example was taken from Cain and 
Nicoll's paper {Trans., 1902, Ixxxi., 1416), from which it 
was shown that over a range of 15 per cent of the reaction 
there was a continuous variation of the velocity constant 
amounting to i2"2 per cent of its mean value, and the 
other experiment at the same temperature did not show a 
much greater constancy. He had, however, no intention 
of disputing that Cain and Nicoll had been able, owing to 
the very slight solubility of nitrogen, to show that the 
decomposition of diazobenzene chloride was possibly, even 
probably, a unimolecular action, but contended that the 
temporary state of supersaturation had seriously aff^ected 
the values of their constants ; in the case of actions which 
evolved more soluble gases, even the order of the reaction 
became untrustworthy. The crucial test of the develop- 
ment of this state was experiment, such as the simple one 
described above. 

*25. "The Triazo-group. Part VII. Interaction of 
Benzhydroximic Chloride and Sodium Azide."' By Martin 
Onslow Forster. 

yN N 

5 : i-Phenylhydroxytetrazole, CeHs'Cf II, is pro- 

\N(OH)N 
duced, instead of the expected benzhydroximic azoimide, 
when sodium azide and benzhydroximic chloride interact ; 
it melts and decomposes at 124°, undergoing spontaneous 
decomposition in the course of a few days, and is resolved 
by alkalis into benzonitrile, nitrogen, and nitrous oxide. 
The benzoyl, ^-toluenesulphonic, and Q - naphthalene - 



stili>honic derivatives are stable, however, decomposing at 
127°, gi — 92°, and 101° respectively. 

*26. "The Triazo-group. Part VIII. Azoimides of the 
Monobasic Aliphatic Acids." By Martin Onslow Forster 
and Robert Muller. 

A description was given of a-triazobutyric, a-triazoiio- 
butyric, and a-triazotsovaleric acids, their amides and ethyl 
esters, with further information concerning triazoacetic and 
o-triazopropionic acids, these compounds having been 
studied with the object of determining the influence of 
environment on the stability of the triazo-group in the 
series. 

*27. " Nitro-derivatives of Ortho-xylene." By Arthur 
William Crossley and Nora Renouf. 

In continuance of the work, briefly described in a pre- 
liminary note {Proc, 1908, xxiv., 58), the action of nitrating 
agents on o-xylene has now been thoroughly investigated, 
with the result that all the theoretically possible mono-, 
di-, and tri-nitro-o-xylenes have been prepared. The 
methods adopted in establishing the constitutions of the 
various nitro-o-xylenes were discussed. 

*28. " The Divergence of the Atomic Weights of the 
Lighter Elements from Whole Numbers." By Alfred 
Charles Glyn Egerton. 

The atomic weights of the first fifteen elements have 
been calculated according to a simple formula, in which a 
constant is multiplied by a constantly increasing whole 
number in order to obtain the divergence from whole 
numbers of the atomic weights. The atomic weights 
of the next thirteen elements have been calculated according 
to a slightly modified formula. The agreement is, in 
nearly all cases, to the second place of decimals. The 
relation suggests a modification of Prout's hypothesis. 

Discussion. 
The President said that he considered this as an epoch- 
making paper. The plan brought forward differed from all 
previous attempts to introduce regularity into the irregular 
series of numbers in the periodic table, inasmuch as it was 
based on a definite physical conception : the addition or 
subtraction of groups of electrons from the atoms ; or, 
what came to much the same thing, definite amounts of 
electro-magnetic attraction which might conceivably alter 
mass. 

*29. " The Constituents of the Bark of Ftunus serotina. 
Isolation of l-Mandelonitrile Glucoside." By Frederick 
Belding Power and Charles Watson Moore. 

The material employed, consisting of the air-dried bark 
of Prunus serotina, Ehrhart, yielded on maceration with 
water an amount of hydrogen cyanide corresponding with 
about 0'075 per cent of its weight. It has been shown to 
contain /-mandelonitrile glucoside, C14H17O6N (m. p. 145 
— 147^; [ajD 29*6°), which has also been obtained in 
the form of its tetra-acetyl derivative (m. p. 136 — 137° ; 
\a]o -24-0°), and an enzyme which hydrolyses ^i-gluco- 
sides. An alcoholic extract of the bark, on distillation 
with steam, yielded small amounts of benzoic acid and an 
essential oil, but no hydrogen cyanide. The non-volatile 
constituents of the bark consisted of a green resin, in- 
soluble in either hot or cold water ; a brown resin, soluble 
in the hot aqueous liquid, but deposited on cooling; and 
material which remained dissolved in the cold aqueous 
liquid. The green resin, amounting to about one per cent 
of the weight of the bark, yielded a phytosterol, C27H46O 
(m. p. 135 — 136°; |o]d -34-0°), palmitic, stearic, oleic, 
linolic, and tiolinolenic acids, a little ipuranol, 
C23H3802(OH)2, and, after acid hydrolysis, oleic acid, 
dextrose, and i-(-methylaesculetin, CioH804. The brown 
resin, amounting to about one per cent of the weight of 
the bark, yielded, after acid hydrolysis, traces of a 
phytosterol, small amounts of oleic acid, /S-methylaesculetin, 
and dextrose, together with insoluble, red, resinous material. 
The portion of the alcoholic extract -which was soluble in 
cold water contained the /-mandelonitrile glucoside, to- 
gether with a quantity of sugar and tannin. It yielded, 



92 



Effective Resistance and Inductance of a Concentric Main. 



(Chemical News, 
1 Feb. ig, 1909 



conductor of a concentric main for high frequency currents 
is obtained : — 

R = {pml2ira){o-'jo'ji + i/awa + o'aSs/w^a* — o-35/m«o)* ; 

where p is the volume resistivity of the conductor, a its 
radius, m* = 8ir' /<//|0, fj. the permeability of the conductor, 
and / the frequency of the alternating current. This 
formula may be used in wireless telegraphy for calculating 
the resistance of a conductor when other conductors 
carrying high-frequency currents are not too close. For 
values of ma greater than 6 the maximum inaccuracy of 
the formula is less than i in 10,000. 

In obtaining the solution, exact formulae are obtained 
for the density of the current at all points on the inner and 
outer conductors. 

The case of a concentric main with a hollow inner con- 
ductor is also considered. The method of obtaining the 
complete solution is explained, and approximate lormulae 
suitable for power transmission cables are given and 
numerical examples worked out. The approximate formula 
for the effective resistance at low frequencies, the proof of 
which is very laborious, has been previously obtained by 
Oliver Heaviside, and the author's solution is an inde- 
pendent verification of its accuracy. For high frequencies 
the formulas become much simpler, and for very high 
frequencies thejordinary well-known formulae are obtained. 
The formulae given enable us to find the impedance of a 
concentric main, taking into account the variation of the 
current-density over the cross section of both conductors 
and the distributed capacity. 

Mr. W. DuDDELL congratulated the author, and re- 
marked that the results obtained in the paper would be 
most useful. It was, he said, customary in dealing with 
high-frequency currents to use several parallel insulated 
wires instead of a single wire in order to increase the 
surface and obtain greater conductivity. He asked the 
author to what extent it was advisable to do this. He 
also asked how far it was valuable to silver-plate copper 
wires for high-frequency currents. 

Mr. A. Campbell observed with regard to Dr. Russell's 
warning that inductance standards might be greatly 
dependent on frequency, that well designed single-layer 
wavemeter coils of highly stranded wire {e.g., 7/36") did 
not show according to his experiments a variation of more 
than I or 2 in 1000 in their self-inductance for frequencies 
from o up to 1,000,000 vibrations per second, the actual 
inductances being from 10 to 200 microhenries. 

Dr. W. H. EccLES remarked that in high-frequency 
work the resistance of a conductor depended on the nature 
of the surface. If a copper wire tarnished its resistance 
altered. Uniform results could be obtained by lacquering 
the wires. He congratulated the author upon the mathe- 
matical results obtained. 

Mr. B. S. Cohen said that a knowledge of the variations 
with frequency of effective resistance and inductance of 
copper conductors was of considerable importance in con- 
nexion with telephonic transmission, and it was to be 
hoped that Dr. Russell would extend his valuable investi- 
gations to conductors lying side by side. The heaviest 
gauge of conductors met with in general telephonic prac- 
tice is 285 mm. in diameter in the case of cables, and 
these conductors are separated by about 25 mm. of com- 
bined paper and air dielectric and twisted together with a 
lay of about 15 cm. 

In the case of overhead open wires, the largest conductor 
in general use is 4 mm. in diameter, although in a number 
of cases a 5"69 mm. conductor has been used. The mean 
axial distance apart of these conductors is about 35 cm. as 
they are rotated in sets of 4 in a foot square. 

Applying Lord Rayleigh's formula for effective resistance 
in these cases we get, for a frequency of 1500 vibrations, 
an increase of i per cent in effective resistance over steady 
current resistance in the case of the 2-85 mm. cable wire. 
A frequency of 1500 vibrations can quite safely be taken 
as the maximum frequency which is of any importance in 
speech articulation. The increase with the 569 mm. open 



furthermore, benzoic, trimethylgallic, and ^-cumaric acids, 
traces of a substance melting at 240 — 241°, and, after 
heating with dilute sulphuric acid, ^mandelic acid and 
/3-methylaesculetin were obtained. 

30. " Benzyl and Ethyl Derivatives of Silicon Tetra- 
chloride." By Geoffrey Martin and Frederic Stanley 
Kipping. 

The authors have made a study of certain benzyl- and 
ethyl-silicon compounds with the object of comparing 
their chemical behaviour with that of corresponding carbon 
compounds. 

Tribenzylsilicon chloride and benzylsilicon trichloride, 
prepared by an improved method of applying the 
Grignard reagent, were decomposed by water, tribenzyl- 
silicol, Si(CH2'C6H5)3"OH, and benzyhnetasilicic acid, 
CeHs'CHa'SiO'OH, respectively being obtained. The 
former when boiled with concentrated hydrochloric acid 
or with dilute aqueous potassium hydroxide is converted 
into tribenzylsilicyl oxide, [(C6H5*CH2)3Si I2O, a change 
not brought about by heating the silicol alone or with 
acetic anhydride ; acetic chloride and benzoic chloride 
convert the silicol into the corresponding chloride. Tri- 
benzylsilicyl oxide is a colourless solid, m. p. 205°, soluble 
in chloroform, but sparingly so in light petroleum or 
alcohol. 

Benzylmetasilicic acid, a resinous substance soluble in 
ether, does not exhibit properties analogous to those of a 
carboxylic acid ; although soluble in potassium hydroxide 
solution, it does not form stable salts with organic bases. 
Its ortho-tsiet, C6H5-CH2-Si(OEt)3, and the oxide, 
[C6H5-CH2'Si(OEt)2]20, were prepared by treating 
benzylsilicon trichloride with ethyl alcohol ; both are 
oils, boiling at 170 — 175°/(70 mm.) and 256 — 26o°/(75 mm.) 
respectively. Attempts to prepare derivatives of silicon 
hexachloride by heating tribenzylsilicyl chloride, benzyl- 
silicyl trichloride, and benzylethylpropylsilicyl chloride 
respectively with sodium or potassium were unsuccessful. 

Diethylsilicon dichloride was prepared from silicon tetra- 
chloride by the Grignard reaction, but the yield was very 
poor ; under certain conditions a considerable proportion 
of the tetrachloride gives non-volatile products, from which, 
after treatment with water, a yellow powder may be ob- 
tained ; this substance is soluble in alkali hydroxides with 
evolution of hydrogen, but insoluble in all other ordinary 
solvents, and seems to have the composition C2H808Si2. 

Diethylsilicon dichloride is decomposed by water, giving 
a polymerised oily silicone, {SiEt20)M ; the hydrol, 
SiEta(0H)2, apparently is not formed. 
(To be continued). 



PHYSICAL SOCIETY. 
Ordinary Meeting, jfanuary 22nd, 1906. 

Dr. C. Chree, F.R.S., President, in the Chair. 

Messrs. A. Bannister, H. Bunskill, F. P. Fuller, T. 
Harris, and N. Willings were elected Fellows of the 
Society. Messrs. G. Nelson, W. F. Higgins, and D. 
Orson-Wood were admitted as Student Members. 

A paper on the ^^ Effective Resistance and Inductance of 
a Concentric Main, and Methods of Computing the Ber 
and Bei and Allied Functions," was read by Dr. Alexander 
Russell. 

The author gives the solution of the problem in terms 
of Kelvin's ber and bei functions and of two analogous 
functions which he calls ker and kei functions. The 
formulas given previously by Maxwell, Raylcigh, Heaviside, 
Kelvin, and Sir Joseph Thomson are shown to be particular 
cases of his solution. Simple formulae for calculating the 
functions used are obtained and are employed to correct 
errors in the tables given by Kelvin and also by Mascart 
and Joubert. The following simple formula for the 
effective resistance R, per centimetre length, of the inner 



Chemical News, 
Feb. 19, igog 



Luminous Efficiency of a Black Body. 



93 



wire at this same frequency is 12 per cent, and with the 
4 mm. wire it is 355 per cent. In a table given in a well- 
known Pocket Book, a 569 mm. conductor is stated to 
increase 15 per cent in effective resistance at 1500 vibrations, 
and he noticed that this figure had been adopted by one 
writer on telephonic matters. Mr. G. M. B. Shepherd 
some time ago worked out the decrease in inductance with 
frequency for wires lying side by side by both Heaviside's 
and Rayleigh's formula;. The following percentage varia- 
tions between o and 1500 vibrations were found for 
5'69 mm. wire: — L 0-37 per cent decrease; r 0-22 per 
cent increase. This is very small, and is due to the fact 
that most of the inductance is due to the field between 
wire and wire. On the other hand, increase of resistance 
in this wire at 1500 vibrations means an increase in 
attenuation of 12 per cent. 

In the case of 5'59 mm. conductors 33 cm. apart, the 
inductance as calculated by Maxwell's form.ula amounts to 
3'2 millihenries, which would reduce the attenuation con- 
stant to one-fifth of its value at 1500 vibrations. It is 
very desirable, therefore, to know the order of decrease of 
inductance with frequency. 

Lastly, I should like to ask Dr. Russell whether he 
thinks that the presence of the adjacent conductors in a 
telephone cable or open wire route is likely to modify the 
skin efTect to any decided extent. 

Mr. Paterson expressed his interest in the paper, and 
asked if the formula given for the effective resistance of 
the core of a concentric main would be of the same form 
if the outer layer were removed. He also asked if the 
skin effect in the outer shell would be altered if the shell 
were cut parallel to its length and laid fiat. 

Prof. C. H. Lees pointed out that a change of sign in 
one of the early equations would lead to the use of the 
Bessel J function instead of the I function. 

Dr. Drysdale congratulated the author, and wished to 
make a suggestion from the point of view of facilitating 
the use of these and other calculations. Electrical measure- 
ments frequently necessitated the employment of higher 
functions, and this involved either troublesome calculations 
or the compilation of bulky tables. He had therefore been 
led to try whether graphical methods could not be em- 
ployed. The plotting of a function J{x) graphically could 
only give values to a low degree of accuracy, but if some 
simple empirical formula y ~ (p{x) were found which approxi- 
mated to the required function, it was possible to express 
the true value /(.r) in the form r<p{x) or c(>{x)-\-a, where r 
or a might be termed a correcting factor or term, which 
only varied between comparatively narrow limits. By 
employing a curve in which log r 01 a was plotted against 
X, it was frequently possible to obtain values of a function 
from a single curve correct to i in 10,000 or closer, and 
which greatly assisted interpolation. He had found this 
of great service in dealing with elliptic integrals and solid 
angles, and thought that it might perhaps also be applied 
to the ber and bei functions. 

The Author, in reply to Mr. Duddell, stated that in his 
opinion stranding and insulating the strands of the wires 
used in wireless telegraphy would not diminish the skin 
effect, if the strands were parallel to the axis of the wire. 
It would probably increase it. Silver-plating the wires 
would be beneficial. The distribution of the high-frequency 
current on the surface of the wires can sometimes be found 
by remembering that the distribution is such that no mag- 
netic induction is produced in the metal. The corre- 
sponding electrostatic problems are consequently of great 
help. Mr. Campbell's experimental results were interesting 
as they show that it is possible to make coils of low time 
constant so that frequencies even as high as a million have 
little effect on their inductance. These coils, however, 
are of little use for many experimental purposes. With 
ordinary laboratory coils a frequency of 10,000 will alter 
their inductance 2 or 3 per cent. If we have two parallel 
cylindrical wires practically touching, the inductance will 
alter from 37726 cm. per unit length to practically zero as 
the frequency is increased. 



Dr. Eccles rightly lays stress on the importance of 
keeping the surface of the wires used in wireless telegraphy 
in good condition and careful lacquering would be very 
beneficial. Mr. Cohen's data about the telephone cables 
used in long distance transmissions are most interesting. 
A piece of metal adjacent to the wire would in many cases 
modify the skin effect, but it would be difficult to deduce 
any general rule as the main current is affected in different 
ways by the induced eddy-currents in the neighbouring 
metal according to the relative positions and magnitudes 
of the metal and wire. Mr. Paterson's question was rather 
hard to answer. In the hollow tube the current-density 
was a maximum at the outer surface. When split open 
and laid out fiat, the current-density would be a maximum 
at the edges. In both cases, the uneven distribution of 
the current leads to an increase in the apparent resistance. 
But which would be the greater he could only determine 
by calculation. In reply to Professor Lees, he stated that 
he had first given the Kelvin functions in terms of Bessel's 
J function, but he had changed it to the I function as this 
made a + instead of a - in the fundamental definition. 
Dr. Drysdale's methods of calculation would be convenient 
in the case of the elliptic functions, but it would not be so 
easy to apply them to periodic functions of continuously 
increasing amplitude. 

A paper entitled " Note on the Luminous Efficiency of 
a Black Body " was read by Dr. C. V. Drysdale. 

The importance of efficient methods of light production 
renders it of interest to ascertain the possibilities of a 
black body as a light radiator at various temperatures, and 
the writer has attempted to obtain these from the radiation 
formula of Wien. The energy radiated between any two 
wave-lengths is written down and the total radiation cal- 
culated. This in conjunction with Kurlbaum's determina- 
tion of the radiation constant, and Lummer and Pringsheim's 
results give rise to the formulas given in the paper. A table 
and curves calculated from these formulae have been worked 
out by Mr. A. F. Burgess, B.Sc, and show the relation 
of the total and luminous radiation and luminous efficiency 
for various temperatures. The comparison of the luminous 
energy so calculated with the intensity of light radiation 
found by Prof. Fery leads to a mechanical equivalent of 
light of about 075 watt per candle, which is a fairly prob- 
able figure. The results show the enormous extent to 
which the luminous efficiency is dependent upon the tem- 
perature and how extremely low it is at ordinary tempera- 
tures. At 1500° C. the efficiency is only of the order of 
I per cent, or less, while at 2000° C. it is about 3 per cent. 
The highest efficiency is obtained at a temperature of 
about 6500° C, and is then only between 40 and 50 per 
cent. This strongly points to the necessity for working 
in the direction of selective radiation or luminescence. 

The Secretary asked the author if he could state 
exactly what he meant by the term " luminous efficiency." 
The ratio of luminosity to energy radiated was different in 
different parts of the spectrum. 

Dr. Russell thought that the physiological effect on 
the eye ought to be considered. If the paper had been 
entitled " The radiation efficiency, for rays contained 
within the limits of the visible spectrum, of a black body " 
it would perhaps have been described better. The sensi- 
bility of the eye to light rays varied not only with the 
wave-length but also with the intensity of the rays and the 
time during which they had been acting on the retina. If 
we only consider the objective stimulus of the luminosity, 
the author's implied definition might be, he thought, 
accepted. But if we consider, as we ought, that the 
subjective sensation produced in the normal eye has to be 
taken into account when judging luminous efficiency, 
another definition is required and the problem becomes far 
more complicated. 

The Author, in reply, said that the term "luminous 
efficiency " was not very generally understood. There 
were three modes of defining it, of which two were due to 
Prof. Nichols, of Cornell University, who distinguished 



94 



Use of the Potentiometer on Alternate Current Circuits. 



I Chemical News, 
1 Feb. ig, 1909 



between " total efficiency " and " radiant efficiency." The 
former of these quantities was the ratio of the luminous 
energy radiated between the spectral limits to the tota' 
energy consumption of the source of light, and the lattei 
the ratio of the luminous energy as above to the total 
radiation from the source. As had just been pointed out, 
however, neither of these definitions took any cognizance 
of the very different luminosities of the various spectral 
colours, and this had been realised by Dr. C. Guilleaume, 
who had proposed to correct the luminous radiation by 
multiplying each ordinate of the radiation curve by a factor 
depending on the luminosity at that ordinate, which wa' 
unity at the point of maximum effectiveness (0-54 n). The 
author had proposed (Proc. Roy. Soc, 1908) the term 
"reduced " total or radiant efficiency, for the efficiency ex- 
pressed on this basis, and this was evidently the most 
rational one. The term " radiant luminous efficiency " 
was, however, recognised and had been correctly employed 
in the paper. 

A paper on " The Use of the Potentiometer on Alternate 
Current Circuits," was read by Dr. C. V. Drysdale. 

The great difficulty in alternate current measurement 
lies in the shortness of the range of the instruments avail- 
able, and there is therefore a great need for some instru- 
ment which, like the direct potentiometer, should be 
capable of measuring P.Ds. and currents of any range 
with accuracy. Two methods of attempting to apply the 
potentiometer principle to alternate current measurements 
seem possible : — (a) The balancing of the alternate current 
P.D. against a continuous P.D. with the assistance of 
some suitable balancing device, or (b) the balancing of 
two alternate current P.Ds. against one another. Sugges- 
tions or attempts at potentiometers on the first principle 
have been made, but seem unlikely to be successful owing 
to the insensitiveness of square law instruments at low 
voltages. The second method presents difficulties in that 
the two P.Ds. to be compared must be identical in magni- 
tude, phase, and frequency, and approximately so in 
wave-form. The author's recent experiments with a 
phase-shifting transformer have led him, however, to 
attempt to use it with a potentiometer, and the measure- 
ments are then made in the same manner as with an 
ordinary direct current potentiometer, except that a 
vibration galvanometer or telephone is substituted for an 
ordinary galvanometer. By interposing an ammeter on 
the dynamometer principle in the main circuit of a potentio- 
meter and deriving the current from the secondary of a 
phase-shifting transformer, it is possible to check the 
instrument with direct current against the standard cell in 
the ordinary way, and then to reproduce the same current 
in the potentiometer circuit and to bring it into coincidence 
of phase with the P.D. to be measured. 

Experiments have been made with this device by Mr. 
A. C. JoUey and the author, first as to the accuracy of 
current measurement using an ordinary low-resistance 
standard, and have been found to give very good agree- 
ment with a Kelvin balance. Other tests have been made 
to obtain the vector difference of potential across a re- 
sistance coil and a choking-coil connected in series, and 
the triangle of voltages so formed was found to be very 
nearly closed. The tests so far made seem to indicate 
that an alternate current P.D. of o*i volt can be measured 
to an accuracy of 0-2 per cent or closer. 

The author has also designed a universal potentiometer 
on this principle which serves both for direct and alternate 
current measurements, and for testing P.D., current, phase, 
power, inductance, capacity, &c. 

Mr. A. Campbell remarked that the first method sug- 
gested by the author had already been described by Mr. J. 
Swinburne (PA^fi. Soc, Dec, 1893). It was also used with 
success at the Reichsanstalt in an improved form by Dr. 
Drewall (Zeit. Instrumentenkunde, April, 1903). Dr. 
Drysdale's phase-turning method was interesting and 
would give good results in many cases. The vibration 
galvanometer, however, was so very muQh more sensitive 



for its own frequency than for others, that it would not 
be likely to give any indication of errors due to other 
harmonics unless they were very pronounced. Hence the 
method must be used with great caution. 

Mr. W. DuDDELL expressed his interest in the paper, 
and asked if the limit of accuracy depended on the sensi- 
tiveness of the galvanometer, and if this was limited by 
the back E.M.F. of the instrument. He pointed out that 
the harmonics could be investigated by tuning up the 
galvanometer to be in unison with them. The device by 
which the phase was changed without changing the current 
was very useful. 

Mr. Ravner pointed out that the accuracy attainable 
depended on the sensitiveness of the Weston voltmeter 
employed. A vital point in the instrument was the phase- 
shifter with the sinusoidal windings. By using two gal- 
vanometers the fundamental and a harmonic could both 
be measured. 

Mr. Paterson, referring to the use of low resistances, 
said that errors might be introduced on account of their 
self-inductance. He thought that the discrepancies be- 
tween the results given by the author's instrument and a 
Kelvin balance might be due to this rather than to in- 
accuracies of the balance. 

The Author, in reply, said that he regretted that time 
had not permitted his making further investigations into 
previous work in this direction, but he had alluded to Mr. 
Swinburne's suggestions, and had claimed no credit for 
the electrostatic device. Mr. Campbell's criticisms mainly 
dealt with wave-form errors. Of course where iron cores 
at considerable saturation were employed, the distortion 
of wave-shape would be considerable, but with the single 
exception of power measurement which should then be 
made with a wattmeter, he knew of no object in such cases 
for accurate P.D. or current measurements. For ordinary 
standardisation of P.D. and current, this difficulty did not 
present itself, as there was no difficulty whatever in ob- 
taining a sufficiently closely sinusoidal wave-form, and the 
wave-forms of the measured and balancing P.Ds. were 
usually similar, being derived from the same source. The 
use of a second vibration galvanometer tuned to the third 
harmonic would be excellent if it was desired to measure 
them, but he believed that it would rarely be necessary, 
and there should be no difficulty in making measurements 
to an accuracy of o-i per cent, with the ordinary alter- 
nators and resistances. For inductance and capacity 
measurements there was of course a positive advantage 
in an instrument which disregarded the harmonics. In 
reply to Mr. Duddell, there was no doubt that the vibration 
galvanometer did give a back E.M.F., as was shown by a 
telephone connected to its terminals when the coil was set 
in motion, and this would probably increase the damping, 
but he did not know the amount of the influence on the 
sensitiveness. He was glad the importance of the sinus- 
oidal winding of the phase-shifting transformer was 
appreciated, and hoped that it would be found effective in 
preserving perfect equality of the potentiometer current as 
the phase was varied. It was true that slots or tunnels 
were employed in the stator core, but they were of con- 
siderable number, and the rotor and stator pitches were 
incommensurable. As to accuracy, it was true that this 
was limited by the dynamometer instrument, but this was 
fairly sensitive as it was always used at its best range, and 
it was to be doubted whether it was possible under any 
ordinary circumstances to make alternate current measure- 
ments to within an accuracy of a few parts in ten thousand, 
owing to variations in the alternator speed or E.M.F. 
Finally, he was certain that no ordinary low resistance 
standards would give any appreciable inductive errors. 
To produce an error in magnitude of o-i per cent would 
require a phase displacement of about 27 degrees, which 
was only slightly exceeded by helical iron wire resistances 
at 50 vibrations, and the straight strip resistances of the 
Reichsanstalt form were almost the perfection of no n- 
inductive resistances. In any case inductance would n pt 
affect the closing of the vector triangle. 



Chbmical News, i 
Feb. 19, 1909 ' 



Chemical Notices from Foreign Sources, 



95 



FARADAY SOCIETY. 

Ordinary Meeting, February gth, 1909. 

Dr. V. H. Veley, F.R.S., in the Chair. 

Dr. S. RiDEAL, F.I.C., read a paper entitled "Applica- 
tion of Electrolytic Chlorine to Sewage Purification and 
Deodorisation by the ' Oxychloride ' Process." 

This paper contains an account of an elaborate investiga- 
tion carried out by the author at Guildford on the use of 
hypochloric solutions in sewage treatment. The experi- 
ments were made on a fairly large scale on the town 
sewage at the Corporation works. This when it emerges 
from the septic tank is dark coloured, more or less fetid 
from the presence of sulphuretted hydrogen, and contains 
very large numbers of bacteria, some of which are capable 
of producing disease. By adding a small quantity of a 
chlorinous liquid the odour is removed, and any nuisance 
arising from sewage distribution is completely avoided. 
But the most important feature is that the effluent is 
rendered harmless, the disease-producing organisms being 
destroyed. After the publication of the author's first ex- 
periments in 1904, the Royal Commission on Sewage 
Disposal visited Guildford and confirmed the results, further 
finding that the chlorine treatment did not hinder the sub- 
sequent purification in the bacterial coke filters. During 
1907 and 1908 Dr. Rideal has continued the trials, and 
finds that the process actually aids the purification, first, 
by causing the filter-beds to mature more rapidly ; secondly, 
by keeping the pipes free from fungus growths ; thirdly, 
by the fact that the avoidance of clogging enables a finer 
filtering medium to be used, which gives better final 
effluents. The form of chlorine used was a hypochlorite 
solution prepared electrolytically. This method of sewage 
treatment has a great sphere of usefulness in preventing 
the pollution of rivers and in entirely removing aerial 
nuisance. 

Mr. W. Pollard Digby hoped that further information 
might be forthcoming concerning some of the more purely 
electro-chemical details of the " oxychloride " process, 
such as the construction of the diaphragms, strengths of 
solutions, salt consumption, costs, &c. He himself had 
found double diaphragms of considerable advantage. He 
emphasised the author's remarks on the importance of 
sewage sterilisation. 

Mr. Shenton pointed out that difficulties were likely to 
arise when storm waters vastly increased the volume of 
water to be sterilised, although this, of course, was only 
occasional. He thought that the prejudice many sanitary 
engineers felt against sterilisation would gradually dis- 
appear when it was realised how economical and practical 
many of the processes really were. Not sufficient was 
generally known about sterilisation. 

Mr. Martin considered the storm difficulty more 
formidable than the last speaker had thought ; to deal 
with twenty to fifty times the dry-weather flow required an 
enormous plant that must be ready to operate at any 
instant. The effect of chlorine in preventing the clogging 
of heads of pipes was an important feature in its favour. 

Mr. A. B. Thomson said it was difficult to give definite 
figures for costs, as these depended upon local charges for 
power and materials. He could not agree with Mr. Digby 
that distributing hypochlorite in carboys could not pay, 
seeing that electrolytic chlorine was a far better purifying 
and sterilising agent than chloride of lime, and, moreover, 
left no lime in solution to clog filters and otherwise give 
trouble. 

Mr. J. FiELDHOUSE said that an automatic valve re- 
gulating the flow of hypochlorite from special storage 
tanks was used to admit of the necessary amount of 
steriliser in time of storm. 

Mr. F. E. Pollard took exception to the use of the 
word " oxychloride," which gave a wrong idea as to the 
constitution of the fluid. 

Dr. S. RiDEAL, in the course of his reply, referred to the 
uncertainty surrounding the constitution of the electrolytic 



fluid. It was usually supposed to consist of hypochlorite, 
but he had recently found that chlorites were present — 
CIO2 ions. No chlorate was formed in the cold, either 
with or without a diaphragm. 



NOTICES OF BOOKS. 



Principles of Sewage Treatment. By Professor Dr. Dunbar. 

Translated by H. T. Calvert, M.Sc, Ph.D., F.I.C. 

London : Charles Griffin and Company, Ltd. 1908. 
A thorough investigation of the characteristics and treat- 
ment of sewage is put before the reader of this book, which 
has been excellently translated from the German. The 
history of river pollution is first discussed in some detail, 
the state of affairs in England being treated quite as fully 
as that in Germany, and the fact that in England there 
are specially difficult circumstances to be combated which 
are not met with on the Continent is fully recognised. The 
second part of the book, in which the present position of 
sewage treatment is considered, is mainly practical, and 
the author shows an extensive knowledge of the most 
modern methods of removing suspended matter and 
putrescibility, while his acquaintance with the procedure 
of even comparatively small sewage works in England is 
remarkably complete. The question of the utility and 
cost of the various methods of purification is discussed in 
the last chapter ; from an impartial consideration of the 
data he has collected and compared, the author has formed 
the opinion that frequently the artificial biological processes 
would be found cheaper than irrigation, especially when 
the towns in question have grown to a certain size. He 
further thinks there is no doubt about the superior efficacy 
of the biological methods, and unhesitatingly decides in 
favour of them. The book has no exact counterpart in 
English, and its translation will no doubt be justified by 
an enthusiastic reception by all interested in the problem 
of the disposal of sewage. 



CHEMICAL NOTICES FROM FOREIGN 
SOURCES. 

NoTB. — All degrees of temperature are Centigrade unless stherwiae 
expressed. 

Comptes Rendus H ebdomadaires des Seances de VAcademie 
des Sciences, Vol. cxlviii.. No. 2, January 11, 1909. 

General Method of Preparing Monoalkyl, Dialkyl, 
and Trialkyl Acetophenones. — A. Haller and Ed. Bauer. 
— The arylalkyl ketones of general formula C6H5CO R 

Rr 
in which R has the composition CH2 — R' and CH<jjjj 

(Ri and R" being both alipathic radicles), may be con- 
verted into di and trialkyl acetophenones of formula 

/Ri 
C6H5COC — R" if they are dissolved in solvents such as 

\Ri" 
ether or benzene hydrocarbons and subjected to the action 
of sodamide and alcoholic iodides. The authors have 
prepared by this method trimethyl, ethyldimethyl, methyl- 
diethyl, triethyl, methylethylpropyl, and allyldimethyl 
acetophenones. 

Laevo-campholic Acid. — Marcel Guerbet. — A yield 
of about 75 per cent of i-campholic acid can be obtained 
by heating in sealed tubes /-borneol with caustic potash 
which has been recently dehydrated by fusion. The 
equation is — 



CsH 



./ 



CHa 



"^\cHOH 



+ KOH = CsH 



■< 



CH3 
CO2K 



+ H2. 



96 



Meetings for the Week. 



I Chemical News, 
I Feb. 19, igog 



The chemical properties of the lasvo acid are similar to 
those of its dextro isomer. It is precipitated from alkaline 
solutions by carbon dioxide. Its ammonia salt dissociates 
very readily, and when the aqueous solution of this salt is 
evaporated at the ordinary temperature the ammonia 
volatilises and the acid is precipitated. Alcohols do not 
etherify it directly whatever the temperature, and to 
obtain ethers it is necessary to allow its anhydride or acid 
chloride to react with alcohols. Its ethers cannot be 
saponified by boiling with aqueous or alcoholic potash. 
Its anhydride, {CioHi70)20, may be prepared by dehy- 
drating the acid with acetic anhydride. When boiled with 
absolute alcohol it is slowly transformed into ethyl cam- 
pholate ; when boiled with aqueous potash potassium 
campholate is formed ; the reaction occurs more rapidly 
with alcoholic potash, but at the same time a little ethyl 
campholate is formed. 

Alkaline Reduction of Orthonitrodiphenyl - 
methane. — P. Carre. — Orthonitrodiphenylmethane, 
C6H4(CH2-C6H5)'(N02)'^ may be prepared by the con- 
densation of orthonitrobenzyl chloride with benzene in 
presence of aluminium chloride and distillation in a current 
of superheated steam. It is best to rectify the raw product 
by distillation in vacuo. When it is dissolved in alcohol, 
boiled, and caustic soda and zinc dust are added, ortho- 
hydrazodiphenylmethane is formed and is deposited from 
the solution on cooling. With dilute acids this sub- 
stance gives dibenzyl -2.2'- diamino -4.4'- diphenyl, 
f— C6H3(CH2— C6H5)''{NH2)'']2. By reducing orthonitro- 
diphenylmethane with zinc and hydrochloric acid ortho- 
aminodiphenylmethane can be prepared, and may be 
obtained in the crystalline state by distillation in vacuo. 



Berichte der Deutschen Chemischen Gesellschafi. 
Vol. xli., No. 18, 1908. 

Determination of Cerium and other Rare Earths in 
Rocks. — M. Dittrich. — When oxalic acid or ammonium 
oxalate is added to a solution of a cerous salt, cerous 
oxalate is precipitated quantitatively. If a solution of a 
ferrous salt is added to that of the cerium salt a precipitate 
is still formed, but it contains iron. When some cc. of a 
neutral ferric salt are present no precipitate is obtained 
with ammonium oxalate or oxalic acid until they have been 
added in excess, when the red colour of the ferric salt is 
changed to the green of the complex ferric oxalate, and 
further addition of oxalate gives a pure white precipitate of 
cerous oxalate. Conversely, the oxalate precipitate is dis- 
solved when a solution of an iron salt is added to it. 
Evidently the stronger ferric ions withdraw the oxalate 
residue from the cerous oxalate precipitate, forming complex 
ferric oxalate ions, and no precipitate can be formed until 
all the iron has been converted into the complex state, To 
separate the cerium quantitatively a very large excess must 
be used, 200 cc. of a saturated solution of ammonium 
oxalate for 02 grm. of cerous sulphate, and 15 cc. of con- 
centrated ferric salt solution. It is better to use am- 
monium oxalate rather than oxalic acid, and to precipitate 
a hot solution. A dilute ammonium oxalate solution must 
be used for washing. In dealing with rocks it is best to 
remove silica by means of hydrofluoric acid and sulphuric 
acid, and to dissolve the residue in a little hydrochloric or 
nitric acid. On the addition of oxalate all the calcium is pre- 
cipitated, and must be removed by igniting the precipitate 
obtained by adding ammonia to the residue after it has 
been dissolved in acid. 

Products of Arc and Spark Discharge in Liquid 
Argon or Nitrogen. — Franz Fischer and George Iliovici. 
— Using electrodeless tubes the authors find that at gas 
pressures above o'l mm. the red argon lines disappear in 
presence of more than 4 per cent of nitrogen. Traces of 
nitrogen do not cause the disappearance of the argon 
spectrum with the authors' apparatus. Electrodeless tubes 
with different forms of outer covering were constructed, 



and electrodeless comparison tubes with argon of density 
1994 (if the density of oxygen is taken as 16) were prepared 
with gas pressures of 3 mm., 0*3 mm., and 0-03 mm. of 
mercury. The silent electric discharge of pure hydrogen, 
argon, and a mixture of hydrogen and argon at the tem- 
perature of liquid air, in no case gave a change of volume, 
from which it could be concluded that a new molecule was 
formed. Experiments with titanium, tin, lead, antimony, 
and bismuth showed with certainty only the formation of 
nitrides ; these may be due to traces of air in the apparatus. 
The nitrides of tin, lead, antimony, and bismuth on 
ignition in vacuo give up their nitrogen as N2, and yield 
ammonium salts with acids. 

New Methods of Preparing Carbon Suboxide. — H. 
Staudinger and St. Bereza. — When oxides, for instance, 
silver oxide, act on malonyl chloride, or silver malonate or 
oxalate on malonyl chloride in the cold, the reaction takes 
place slowly, but in boiling acetic acid an energetic 
reaction takes place, and carbon suboxide is formed, but no 
ketene. The malonic acid anhydride first formed may 
split up, not into ketene and carbon dioxide, but into carbon 
suboxide and water, or, and this is the more probable sup- 
position, the oxide splits the chlorine off from the malonyl 
chloride, and the suboxide is thus formed directly, 

CH2<g°g+ Ag20 = Cggg + 2AgCl -i- H2O. 



NOTES AND QUERIES. 



*4,* Our Notes and Queries column was opened for the purpose of giving 
and obtaining information likely to be of use to our readers generally. 
We cannot underiake to let this column be the means of transmitting 
merely private information, or such trade notices as should legitimately 
come in the advertisement columns. 

Myrbane Oil — Can any reader inform me whether there is any- 
thing that may be added to myrbane oil to take away (or materially 
reduce) the very pungent smell without detracting from the property it 
possesses of removing paint stains and other marks from clothing, &c. 
-R. G. L. 



MEETINGS FOR THE WEEK. 



Monday, 22nd.— Royal Society of Arts, 8. (Cantor Lecture). " Modern 

Methods of Artificial Illumination," by Leon Gaster. 

Tuesday, 23rd.— Royal Institution, 3. "Evolution of the Brain as 

an Organ of Mind," by Prof. F. W. Mott, F.R.S. 
Wednesday, 24th. — Royal Society of Arts, 8. " Hand-made Papers of 
diiiferent Periods," by Clayton Beadle and H. P. 
Stevens. 

Society of Dyers and Colourists, 8. " Series of 

Azo-dyes derived from the Aminosulphon- 

amides," by G. T. Morgan and Frances M. G. 

Micklethwaite. 

Thursday, 25th. — Royal Institution, 3. "Problems of Geographical 

Distribution in Mexico," by Hans Gadow, F.R.S. 

Royal Society of Arts, 4.30 " The Buddhist and 

Hindu Architecture of India," by A. A. Mac- 

donell, M.A., &c. 
Friday, 26th.— Royal Institution, g. " Osmotic Phenomena, and their 
Modern Physical Interpretation," by Prof. H. L. 
Callendar, F.R.S., &c. 

Physical, 5. (At Finsbury Technical College, E.G., 

by invitation of Profs. Thompson and Coker). "A 
Laboratory Machine for applying Bending and 
Twisting Moments simultaneously," by Prof. Coker. 
" The Self-demagnetising Factor of Bar Magnets," 
by S. P. Thompson and E. W. Moss. Exhibition 
of Optical Properties of Combinations of Mica and 
Selenite Films (after Reusch and others) in con- 
vergent Polarised Light, by S. P. Thompson. Ex- 
hibition of (tt) Experiment to Illustrate the Tem- 
perature of Equal Density of Aniline and Water; 
('1) Simple Form of Thermo-electric Pyrometer for 
Students' Use ; (r) Combined Metre-bridge and 
Potentiometer, with New Tapping -key Device, 
for Pyrometric and General Laboratory Work ; 
(d) New Form of Carbon-plate Rheostat, suitable 
for Control of small Electric Furnaces, by C. R. 
Darling. 
Saturday, 27th.- Royal Institution, 3. "Properties of Matter," by 
Prof. Sir J. J. Thomson, F.R.S, 



£heMical ^^eWs, I 
Feb. 26, igog I 



Scandium. 



07 



THE CHEMICAL NEWS 

Vol XCIX., No. 2570. 



SCANDIUM.* 

Part I. — The Separation of Scandium from 

Wolframite from Zinnwald. 

By R. J. MEVER. 
(Concluded from p. 87). 

B. — Precipitation with Hydrofluoric Acid. 
Very little is known of the properties of the fluorides of 
the rare earths. It is only known that, with the exception 
of zirconium fluoride, they separate as difficultly soluble 
precipitates from neutral solutions of the salts. It has been 
shown that scandium fluoride is almost insoluble in a 
fairly strongly acid solution, a property which it shares with 
thorium fluoride, while the fluorides of the other earths are 
considerably more soluble in acids, but they can be almost 
completely precipitated if a large excess of hydrochloric 
acid is added to a solution of their salts. In order to pre- 
pare scandium in the pure state it is essential that the 
fluoride precipitate obtained from a solution rich in man- 
ganese and iron should be quite free from manganese, and 
that the accompanying cerium and yttrium earths should 
mostly remain in solution. 

The oxide obtained after the concentration process with 
oxalic acid is dissolved in hydrochloric acid, the solution 
is evaporated to dryness on the water-bath, and the residue 
is taken up with water and some hydrochloric acid. The 
solution is placed in a lead dish, and hydrofluoric acid is 
added in the cold until the precipitate, which at first dis- 
solves, remains ; the whole is then heated for some time 
on the water-bath. The slimy precipitate then settles well, 
and it is best to aspirate it on a Nutschen filter into an oiled 
filter flask, and to wash with hot water. The precipitate 
consists of calcium fluoride, lead fluoride, a little iron 
fluoride, and the fluorides of the rare earths. It is then 
decomposed by concentrated sulphuric acid in a platinum 
dish ; the solution is evaporated until a damp mass is 
obtained, and is then boiled with water. The calcium is 
removed by repeated precipitation with ammonia, and the 
hydroxides free from calcium are boiled with oxalic acid 
solution. In this way a finely crystallised oxalate is 
obtained, while the last traces of iron remain in the solu- 
tion. The oxides obtained on ignition must be perfectly 
white. In diff'erent experiments the yield from i kilogrm. 
of wolframite was i'4 to i'6 grms. of oxide, and 3*0 to 33 
grms. of oxide from i kilogrm. of technical wolframite 
oxides. 

Owing to the success of the experiments with the fluoride 
purification, it seemed feasible to give up the preliminary 
concentration with oxalic acid and to precipitate the 
original solution at once with hydrofluoric acid. This was 
found to be perfectly satisfactory as long as only small 
quantities, i.e., about a kilogrm., of wolframite oxides were 
being treated. With larger quantities it was difficult to 
get suitable vessels for the precipitation of large volumes 
of liquid with hydrofluoric acid ; moreover, a very con- 
siderable amount of hydrofluoric acid is used, because the 
greater part of the aluminium, in which the solutions obtained 
from impure material are very rich, must be precipitated as 
fluoride in order to be sure of completely precipitating the 
rare earths. For this reason it is usually best to perform 
the preliminary concentration with oxalic acid. 

By this combination of methods3o kilogrms. of wolframite 
oxides were worked up in several portions. The yield 
amounted to 75 grms. of a raw scandium containing 
always over 95 per cent of scandium oxide. As the oxides 

♦ ZtUschrift Jiir Anorganische Ckemie,lx., 134, November 17, 1908. 



on extraction with hydrochloric acid left 6 grms. of 
insoluble residue, the result corresponds to a yield of 0-25 
per cent of the raw, and 0-29 per cent of the pure material. 
(When smaller quantities were used the yield rose to 0-3 
to 033 per cent of the raw material. The losses are due 
to the difficulty of treating such large quantities in a 
scientific laboratory). 

C. — Methods with Hydro fluosilicic Acid. 
The combined oxalate and fluoride method, as we have 
seen, gives good results, but certain definite instructions 
have to be very carefully followed ; moreover, it is very 
tedious when large quantities of raw material have to be 
worked up. In addition, exceedingly large quantities of 
oxalic acid are absolutely necessary to precipitate the 
small quantities of the rare earths, and finally there are in- 
conveniences attached to the use of hydrofluoric acid, due 
to its attack upon the apparatus, and also to its bad effects 
upon the health. It therefore seemed desirable to try to 
find a more convenient, less lengthy, and at the same time 
economical method. This was accomplished by replacing 
the hydrofluoric acid by hydrofluosilicic acid or sodium 
silicofluoride. It was first observed that the different 
groups of the rare earths behave very differently towards 
hydrofluosilicic acid. In neutral solution all rare earths 
are precipitated when hydrofluosilicic acid is added and 
they are boiled ; on the other hand, in acid solution no 
precipitate is formed in solutions of the yttrium earths 
even on boiling, while with the cerium earths — cerium, 
lanthanum, praseodymium, neodymium, samarium — very 
striking differences are observed in their precipitability ; I 
shall discuss these more fully later. Scandium, even in 
strongly acid solution, is gradually completely precipitated 
on boiling, and it is thus obtained quite free from foreign 
earths. These reactions merit a more thorough study, 
especially in relation to the possibility of successfully 
separating the rare earths with their help. The scandium 
is not precipitated as silicofluoride, but as fluoride, the 
silicofluor ions, SiFe", being decomposed on boiling, 
yielding silicon fluoride and F' ions : — 

Sc2(SiF6)3 = 3SiF4-»-2ScF3. 
The yttrium earths are not precipitated under the same 
conditions, because with them the decomposition does not 
occur at any rate in acid solution. (Cerium earths are 
present only in very small quantities in wolframite ; of 
them, neodymium and samarium show a certain tendency 
to be precipitated by hydrofluosilicic acid). This reaction 
was applied to the separation of scandium from the solu- 
tion of wolframite oxides. It was found that in this case 
concentration by means of the oxalate could be omitted 
without any ill effects, for comparatively small quantities of 
hydrofluosilicic acid were sufficient to precipitate from a 
solution saturated with iron salts, the earth nearly free 
from iron and calcium and quite free from manganese and 
lead. As an acid reaction of the solution does not hinder 
the precipitation, the oxides can be dissolved in an excess 
of acid without subsequently neutralising or evaporating. 
The whole separation process is thus greatly simplified. 
Instead of aqueous hydrofluosilicic acid, commercial pure 
sodium silicofluoride may advantageously be used, the 
operation being carried out as follows : — One kilogrm. of 
the wolframite residues is dissolved in 3 litres of raw 
hydrochloric acid, the powder being introduced into the 
boiling acid. After drawing off the deposit of silica and 
boiling with dilute hydrochloric acid the filtrates are put 
together and boiled, and 40 grms. of solid sodium silico- 
fluoride are added, meanwhile stirring the whole. The 
boiling is then continued for about half-an-hour, when the 
scandium fluoride separates completely in the form of a 
white pasty precipitate ; it settles after standing for some 
time, and then the supernatant acid liquid, which contains 
iron, can be decanted off. The precipitate is then filtered 
on a Nutschen filter, and again boiled with very dilute 
hydrochloric acid (i litre of water to 300 cc. of dilute 
hydrochloric acid). It is then perfectly colourless. As 



98 



Scandium. 



J Chemical News, 
I Feb. 26, 1909 



described above, the fluoride is decomposed with sulphuric 
acid, the sulphate solution is precipitated with ammonia, 
and finally the hydroxides are decomposed with oxalic acid. 
When the oxalate thus obtained is ignited, a perfectly 
white scandium oxide, almost free from foreign matter, is 
obtained. As with the other methods the yield amounts 
to 3 to 3-3 grms. SC2O3 from i kilogrm. of wolframite 
oxides. 

Composition of Oxides obtained by Methods A, B, and C. 
The oxides obtained by the three above described methods 
of isolating scandium from wolframite oxides were in- 
vestigated : — (i) By examining the spark spectrum ; (2) by 
determining the atomic weight. The atomic weight was 
determined by Nilson by converting a known weight of the 
oxide into sulphate; i.e., by finding the ratio of R2O3 to 
R2(S04)3. After various experiments in this direction it 
was found to be preferable to reverse the process ; i.e., to 
convert an unweighed amount of oxide into sulphate, and 
to change this again to oxide by strong ignition after 
weighing, for when the oxide is dissolved in acid and the 
sulphate solution is evaporated in a crucible losses very 
often occur owing to spirting ; these losses, of course, do 
not matter if we start with sulphate. (Ignited scandium 
oxide does not dissolve completely in acids until it has been 
boiled for a long time). This method is also quicker. 
Moreover, in order to convert the oxide into sulphate, it is 
not necessary first to dissolve the former in hydrochloric 
or nitric acid and then add sulphuric acid to the solution 
as with the other rare earths ; the scandium oxide can be 
dissolved directly by boiling with dilute sulphuric acid, as 
its sulphate is readily soluble. In order to get the neutral 
anhydrous sulphate, a temperature of 430 — 450° is required. 
This operation was carried out in a small electric resistance 
furnace. The temperature was measured with a Le 
Chateliei's pyrometer and a gauged millivoltmeter. In 
this way absolute constancy of weight could be obtained 
easily. The conversion into oxide was performed by 
igniting before the blowpipe. The results of some atomic 
weight determinations are given in the following table : — 

Weighed Weighed At. wt. 
No. Method of separating oxide. R2(S04)3- R203- R"". 

1. Oxalic acid + hydrofluoric acid 29876 i'i4i9 50-2 

2. Oxalic acid + hydrofluoric acid 1-9989 07478 47-8 

3. Hydrofluoric acid alone . . .. 07392 0-2764 47-6 

4. Hydrofluosilicic acid .. .. 3-0800 1-1370 46-2 

5. Hydrofluosilicic acid .. .. 3-0678 1-1268 45-6 

6. Sodium silicofluoride . . . . 2-0329 0-7523 46-4 
Appearance of Oxide. — No. i, yellowish ; Nos. 2 and 3, 

very faintly yellow ; Nos. 4, 5, and 6, pure white. 
As 44- 1 has been taken for the atomic weight of scandium 
since Nilson's work was published, it follows that the 
" unfractionated " oxide obtained by the above described 
precipitation methods possesses a high degree of purity. 
This is specially the case with the preparations obtained 
by the hydrofluosilicic acid method, while the specimens 
prepared by precipitation with oxalic acid and hydrofluoric 
acid, or with hydrofluoric acid alone, are not so pure. 
Hence it follows that hydrofluosilicic acid in acid solution 
is a specific reagent for scandium, while oxalic acid pre- 
cipitates all the earths which are present in the raw 
material, and hydrofluoric acid does not completely 
eliminate the accompanying cerium and yttrium earths ; 
at any rate, the result with these reagents depends largely 
on the acidity of the solution and the amount of reagent 
added. In concentrated solution Specimen i (see above 
table) showed plainly the strongest absorption bands of 
erbium, and also the most intense neodymium bands in 
the yellow ; it was obtained by precipitating the fluoride 
from an almost neutral solution with a large excess of 
hydrofluoric acid. In Specimens 2 and 3, which were pre- 
pared from acid solutions, the absorption bands could not 
be seen clearly, but according to Prof. Eberhard's com- 
munication the examination of the arc spectrogram of 2 
showed the undoubted presence of cerium and yttrium 



earths ; the lines of yttrium and ytterbium in particular 
were plainly visible, while in Specimen 5 only traces of 
foreign earths could be detected. According to an 
approximate estimation even the relatively most impure 
specimen, No. i, contains at least 93 to 95 per cent of 
scandium. 

D. — Removal of the Foreign Earths by PreciHtation with 
Sodium Thiosulphate. 
According to the plan of this research all fractionation 
methods, which must of necessity waste the valuable 
material more or less, had to be avoided, and only pre- 
cipitations could be employed. This scheme could be 
carried through owing to the peculiar nature of scandium. 
The spectrographic examination of raw scandium had 
shown that it still contains small quantities of yttrium 
earths. Sodium thiosulphate was found to be an excellent 
reagent for completely removing all foreign earths. Cleve 
had already observed that scandium is precipitated when 
boiled with thiosulphate, but he stated that the precipita- 
tion was incomplete. This restriction was undoubtedly 
based upon an error, and may probably be explained by the 
fact that Cleve's preparation contained some ytterbium. 
(As Pro'. Eberhard points out, the spectrographic examina- 
tion of Cleve's scandium shows the presence of a consider- 
able amount of ytterbium ; this also explains why Cleve's 
values for the atomic weight, 44-91 and 45-12, are too high). 
As a matter of fact, pure scandium is precipitated quanti- 
tatively from its neutral solution by the addition of thiosul- 
phate at 100° ; it separates in the form of a grey flaky 
precipitate, which consists of scandium thiosulphate — not 
the hydroxide. Other rare earths, except thorium, are not 
precipitated by this reagent. Thus, by a thiosulphate 
precipitation a yellow oxide of atomic weight 50 could be 
converted into a pure white oxide of atomic weight 45 — 46, 
the accompanying earths remaining dissolved in the 
filtrate. Even ytterbium, which is most persistently re- 
tained by scandium when the method of fractionally 
fusing the nitrates, used by Nilson and Cleve, is employed, 
may be removed in this way. (I obtained a specimen of 
chemically pure ytterbium oxide through the kindness of 
Dr. Urbain, of Paris). Thus it might be expected that 
chemically pure scandium could be obtained by this method. 
However, it was found that this process always gave a 
product the atomic weight of which was higher than 46. 
A raw scandium, obtained by precipitation with hydrofluo- 
silicic acid, of atomic weight 46-2 (No. 4 in the above table), 
was divided into two fractions by sodium thiosulphate ; a 
small amount of the foreign earth remained dissolved in 
the filtrate. The result of this experiment appeared 
remarkable at first sight, for it. was found that the first 
fraction possessed a higher atomic weight than the 
original product. 

Raw Earth, 46-2. 
Thiosulphate pre- Weight of Weight of Atomic 

cipitate. sulphate. oxide. weight. 

Fraction I. 2-1985 0-9170 46-g 

„ II. 1-3610 0-5012 45-9 

This experiment was repeated somewhat differently with 
a larger amount of scandium oxide ; the result obtained 
was the same. Ten grms. of oxide of atomic weight 45-6 
(No. 5 in the above table) were dissolved in hydrochloric 
acid ; the neutral chloride solution was boiled and pre- 
cipitated with the calculated amount of sodium thiosulphate 
necessary for complete precipitation (60 grms.). By pre- 
cipitation of the filtrate with ammonia 0-1347 g'^'"- = i'34 
per cent of a brownish mixture of earths, not precipitated 
with thiosulphate, could be isolated. The thiosulphate 
precipitate was decomposed with hydrochloric acid, and 
the solution was precipitated with oxalic acid after 
evaporation. The oxide obtained by igniting the oxalate 
had the atomic weight 46-4. 

Raw Earth, 45-6; Thiosulphate Precipitation. 

Weight of sulphate. Weight of oxide. Atomic weight. 

1-9332 0-7148 46-4 



Chemical News, 
Feb. 26, 1909 



Fruit of Medeola Vtrginica, &€. 



99 



This increase in the atomic weight in the thiosulphate 
precipitate could only be explained by supposing that it 
was due to the concentration of an earth of higher atomic 
weight also precipitated by sodium thiosulphate. This 
could only be thorium. Naturally the presence of this 
substance cannot be proved qualitatively with certainty, 
for at present no reaction has been discovered by which 
small quantities of thorium can be detected in presence of 
scandium. But in this case also the spectrographic 
examination gave a significant result. According to Prof. 
Eberhard, the earth obtained by precipitating with thiosul- 
phate is quite free from cerium and yttrium earths, but 
in the arc spectrum it shows perfectly plainly the lines of 
thorium. On the probable assumption that thorium is the 
only impurity which is not separated from the scandium 
when thus purified, and that the atomic weight 44* i given 
by Nilson is correct, the amount of thorium present may 
be calculated to be about i percent. The presence of this 
impurity in scandium oxide was to be expected from the 
nature of the separation process adopted, if thorium was 
contained in the wolframite earths ; for like scandium it 
would be completely precipitated in acid solution, both by 
hydrofluoric acid and by hydrofluosilicic acid. 

As was to be foreseen, the removal of this last small im- 
purity is very difficult, owing to the great similarity in the 
behaviour of scandium and thorium. Besides resembling 
thorium in being precipitated by hydrofluoric acid, hydro- 
fluosilicic acid in acid solution, and by thiosulphate, 
scandium compounds like those of thorium, are readily 
soluble in alkali carbonates and alkali oxalates, and these 
solutions ate precipitated on boiling with much water. 
Scandium is also precipitated to a certain extent by 
hydrogen peroxide in neutral solution. As for any dif- 
ferences in behaviour, these cannot be used for the 
separation of the very small quantities of thorium in 
question, as the experiments we have described have shown. 
The most striking differences are, for example, the be- 
haviour of the strongly ignited oxides towards acids, in 
which thorium oxide is insoluble, while scandium oxide 
is soluble after prolonged boiling ; also the very great 
difference in the solubilities of the oxalates of the two 
elements in acids, the well developed tendency of thorium 
salts to undergo hydrolysis, and finally the volatility of 
scandium chloride. There can be no doubt that the more 
thorough study of these and other distinguishing reactions 
would lead to the solution of the problem, and that it would 
then be possible to prepare scandmm in a perfectly pure 
state without performing any fractionations whatever.* 
As in the course of new preparation processes performed 
on a large scale, I shall shortly obtain some hundreds of 
grms. of scandium oxide, I shall be able to proceed at once 
to a thorough study of this interesting element which has 
up to the present been so very seldom prepared. With the 
yields now obtained, i kilogrm. of 98 or gg per cent 
scandium oxide can be prepared from 330 kilogrms. of 
wolframite oxides, which can be prepared on a manu- 
facturing scale without any difficulty. 

The preparation of scandium from other raw materials, 
tin-stone and tin-slag, will be described in a second article. 
The experiments on the purification of the oxide will be 
continued. In addition, the scandium compounds will be 
thoroughly studied from a chemical and physical-chemical 
point of view, and the atomic weight will be re-determined. 

I must not omit to express my hearty thanks to Herr 
Max Speter for the valuable assistance he gave me in dis- 
covering and working out the hydrofluosilic acid method. 

Summary . 
I. Wolframite from Zinnwald contains 0-14 to o"i6 per 
cent of rare earths, including a considerable amount of 
scandium oxide. When the mineral is opened up with soda 
all the scandium goes into the oxides (iron, manganese, 
calcium, lead) separated fiom sodium tungstate by extrac- 

♦ Experiments which were performed while this article was being 
printed have already indicated a method of removing thorium. This 
fDethod will be described in a subsequent article. (Correction). 



tion with water. These raw wolframite oxides, which 
contain 0-30 to 0-33 per cent of scandium oxide, form the 
raw material for the preparation of scandium. 

2. Two methods of separating scandium from the 
wolframite oxides were worked out. 

a. Precipitation with hydrofluoric acid from an inter- 

mediate product in which the scandium had been 
concentrated by an oxalic acid precipitation. 

b. Precipitation with hydrofluosilicic acid or sodium 

silicofluoride in acid solution. 

Note. — The preparation of scandium by the combined 
oxalic acid, hydrofluoric acid method, has been patented 
by the author (D.R.P. 202523). The method with hydro- 
fluosilicic acid is the subject of a specification which is 
now before the Royal Patent Office. 

3. The raw scandium oxide prepared by the above 
methods still contains small quantities of foreign earths 
(yttrium earths, especially yttrium and ytterbium), par- 
ticularly if method b has been used. These may be com- 
pletely removed by precipitating the scandium with sodium 
thiosulphate. 

4. The scandium when freed from cerium and yttrium 
earths has the atomic weight 45 to 46 ; it still contains 
about I per cent of thorium. 



THE FRUIT OF MEDEOLA VIRGINICA AND 

AMPELOPSIS QUINQUEFOLIA. 

By LOIS E. POYNEER and H. LEROY DUFFIN. 

The fruit of Medeola Virginica (Indian cucumber) was 
gathered at Sylvan Beach, New York, on the sandy shores 
of Oneida Lake, August 30 to September 6, 1907. Only 
about one-half of the fruit seemed ripe. We found it 
necessary to leave the locality early in September, other- 
wise the whole quantity would have been gathered when 
fully ripe. It was dried in an oven at about 105°. Each 
fruit averages about 0-05 grm. in weight. They are about 
the size of currants, dark brown, almost black in colour. 
There is on each a rather hard outer shell, and within this 
are six to twelve small nutlets which are very hard. These 
nutlets are dark coloured like the outside of the fruit. 

The Sugars. 

We placed loo grms. of the fruits in a 500 cc. flask, 
with which was connected a back-flowing condenser. 
300 cc. of alcohol was added. The flask and contents 
were kept on a warm water-bath for ten hours, and the 
alcoholic extract poured into a second flask, and the 
alcohol removed by distillation. The same alcohol could 
be used over and over again. This treatment was con- 
tinued until all the sugar was removed, as shown by 
Fehling's solution. The time necessary was six weeks. 
Each separate portion of alcoholic extract was brown in 
colour, the intensity of the colour gradually diminishing. 
The residue in the flask after the alcohol had distilled over 
had an odour of black-berry brandy and burned apple 
butter. 

To determine the amount of sugar, water was added to 
the residue from the alcohol, sufficient to make 350 cc. of 
solution, and i cm. was added to 50 cc. of distilled water. 
This was titrated with Fehling's solution, of which 10 cc. 
corresponded to 005 grm. sugar. This indicated 666 per 
cent of sugar, a figure which is probably too high. When 
yeast was added to a solution of the sugar it easily 
fermented, and was converted into alcohol. 

A small quantity of the sugar solution was digested with 
purified bone-black, after which the solution was quite 
clear. Then we placed in a test-tube one-tenth grm. of 
the dried sugar, two-tenths grm. pure phenyl hydrazine, 
three-tenths grm. sodium acetate, and 2 cc. distilled water. 
On immersing this in a bath of boiling water the osazone 
began to appear in half a n)inute, and al| seemed to hav? 



100 



Fruit oj Medeola Virginica, &c. 



Chemical I^ews, 
Feb. 26, 1909 



separated in one minute, indicating that the sugar is 
fructose. The osazone was filtered off and re-crystallised 
a number of times from alcohol, but we did not succeed 
in obtaining sufficient of the pure substance to determine 
the melting-point. 

The Oils. 

The portion of the fruit that remained after the alcoholic 
extraction was dried in an air-bath, and the husks separated 
by rubbing. We attempted to remove the husks by 
"panning" with water, but were unsuccessful, as some of 
the nutlets were also inclined to float away, and finally 
most of the husks were separated by gently blowing upon 
them. 

The nutlets proved to be very hard. They could not be 
crushed with a heavy iron mortar and pestle, but by 
running them three times through a coffee grinder, set 
with a small aperture, they were ground moderately fine. 
They had an odour which reminded one of varnish. 

The ground nutlets were treated with ether in a flask 
with an inverted condenser, as the fruits were first treated 
with alcohol. 

53-2299 grms. of the dried nutlets gave 5'477o grms. of 
oil. After standing in a test-tube there seemed to be two 
distinct oils. The top layer was removed with a capillary 
tube. It was quite light in colour. On standing in an 
open tube this evaporated during the night. The oils were 
again obtained from a second portion of berries, but the 
lighter portion was accidentally lost. On placing them in a 
freezing mixture, they did not solidify. A small portion of 
oil was extracted by the alcohol with the sugars. On 
treating this extract with ether, the oil was easily recovered 
and added to the main portion. 

The heavier of the two oils, light in colour, attractive in 
appearance, and apparently pure, was saponified with a 
normal solution of caustic soda, and the saponification 
equivalent was found to be 254*88. This indicates that it 
belongs to the group of marine oleins. The low equivalent 
shows that it is not one of the waxes. According to Allen, 
the equivalent of porpoise oil is 256 to 260, and the specific 
gravity is 092. We found the specific gravity of our oil 
to be 0*935. It saponified with ease and formed consider- 
able soap. These are likewise characteristics of porpoise 
oil. 

After purifying th« alcoholic extract with bone-black, it 
gave the test for oxalic acid, but no other acids were 
detected. When a berry held in platinum wire was inserted 
in the Bunsen flame, a decided reaction for potassium was 
noticeable. 

The Ash. 

We burned 37530 grms. of the fruit in a platinum dish, 
and obtained an ash weighing 0-1468 grm., or 3-91 per 
cent of the whole. The constituents were determined as 
follows : — 



SiOz . . 


.. 1800 pet 


cent 


of the ash 


AI2O3 .. 


. . 0-66 






FejOs .. 


2-65 






CaO .. 


.. 6-13 






MgO .. 


8-04 






K2O .. 


. . 24-50 






NajO .. 


.. 163 







The ash effervesced on treatment with hydrochloric acid, 
but neither the carbon dioxide nor the sulphate content 
was determined. The P2O5 was estimated from the residue 
after the alcohol and the ether extraction. We obtained 
from 2*2748 grms. of the dried residue, 0-1515 grm. of ash, 
or 5*26 per cent. It would naturally be expected that the 
percentage of ash would be higher than in the original fruit. 
We obtained a half mgrm. of P2O5, or 0*33 per cent of 
the ash. 

The Ampelopsis Quinquefolia. 
The Ampelopsis quinquefolia (Virginia Creeper, also 
called American Ivy) is a common woody vine, growing in 



rich ground, climbing extensively, blossoming in July, 
ripening its small black berries in October, leaves turning 
bright crimson in autumn (" Gray's Manual "). 

The Sugars. 

A quantity of the ripe blackish berries were picked from 
the vines on the Cornell College Campus, October 19, 
1907. They were afterwards dried at 105°. The average 
weight was 0-116 grm. 

We weighed out 150 grms. of the dried fruit in a 500 cc. 
flask, filled it three-fourths full of alcohol, attached an 
inverted condenser to the flask, and heated it on the 
water-bath. The alcohol was poured off, and a fresh 
portion added every six hours. This operation was con- 
tinued several days until no more colouring matter was 
given from the fruit, and the extract gave no sugar test 
with Fehling's solution. The alcoholic extract was dark 
reddish brown in colour, and gave a decided acid reaction 
with litmus-paper. After all the alcohol was removed by 
distillation, sufficient water was added to the residue to 
make 350 cc. This, tested with Fehling's solution, was 
found to contain 91 grms. of sugar, or about 60 per cent of 
the original fruit. 

A portion of the extract was treated for several days with 
purified bone-black, which removed most of the colouring 
matter. This sugar solution was next evaporated to dry- 
ness. We placed in a test 08 grm. phenyl hydrazine 
hydrochloride, 08 grm. of sodium acetate, and 02 grm. of 
the sugar, and dissolved in a little water. The solution 
was placed in a boiling water-bath, and the osazones 
appeared in one to one and a-half minutes, indicating 
fructose. After crystallising the precipitate from alcohol, 
the melting-point was found to be 204°. 

The Acids. 
The extract that had been purified with bone-black was 
shown to contain oxalic acid and tannic acid. 

The Oils. 

After extracting the fruits with alcohol, they were dried 
in an air-bath and ground to a fine powder. The oils were 
extracted with successive portions of ether, as the sugars 
had previously been extracted with alcohol. We obtained 
16-5054 grms. of oil, equivalent to 11-27 P" ^^^^ o^ ^^^ 
fruit. On standing, the oil soon separated into two dis- 
tinct portions, one considerably darker than the other ; the 
darker portion was also the heavier. 

We saponified both portions separately with alcoholic 
caustic potash solution, but arrived at no satisfactory 
results. The darker oil easily solidified in a freezing mix- 
ture and afterwards melted at 0-8^. The specific gravity 
of the two portions shaken together was found to be 09503. 
The oils were probably palmatin and olein, probably on 
account of the high percentage of sugars. We received 
0-0976 grm. of ash from 2 grms. of the crushed fruit, or 
4-88 per cent. This analysed as follows *. — 



Silica .. 


0*00 


per 


cent of the ash 


Fe203 .. 


1-86 








AI2O3 .. 


4*8i 








CaO .. 


.. 4227 








MgO .. 


.. 390 








K2O .. 


.. 2815 








NaaO .. 


•• 397 








P2O5 . . 


. . 1004 








SO3 .. 


500 









No test was made for nitrogen or proteids. 

The fruit held in the Bunsen flame with a platinum wire 
gave a decided potassium reaction, both with and without 
the blue glass. 

We desire to thank Prof. N. Knight for encouragement 
and assistance in carrying on the foregoing work. 

Cornell College, February 6, 1909. 



Chemical News, I 
Feb. 26, 1909 ' 



Atomic Weight of Tellurium. 



lOI 



THE ATOMIC WEIGHT OF TELLURIUM. 
By VICTOR LENHER. 

The atomic weight of tellurium has received an unusual 
amount of study ever since attention was directed to it by 
the statement of Mendeleeff in his memorable paper before 
the Russian Chemical Society in 1869. In outlining the 
principles of the periodicity of the elements he observed 
that " the atomic weight of tellurium must be between 123 
and 126, and cannot be 128." 

Various lines of experimentation have been followed to 
test the validity of this assertion : — (a) Critical studies have 
been on the elementary character of tellurium, but nothing 
thus far has developed which would warrant a belief in its 
complexity from the character of the experimental evidence 
produced, (h) The spark spectrum of the element has been 
studied, especially by KHhner {Ann., cccxix., i), who 
purified his material by various processes, and who used 
tellurium from various sources. His results show no dif- 
ferences in the spectrum, (c) Numerous atomic weight 
determinations have been pubUshed from time to time with 
tellurium from various sources, but the results of all the 
experiments seem to indicate that the figure is higher than 
that of iodine. 

It is the purpose of this paper 10 describe a series of 
atomic weight determinations made with three specimens 
of tellurium from widely different sources, and by the use 
of a method different in principle from any previously used 
with tellurium. 

The salt chosen for the work has been the double bromide 
of tellurium and potassium, KjTeBre, a salt readily obtained 
in a high degree of purity and one of the most strongly 
crystalline derivatives of tellurium. This salt when heated 
in a current of chlorine is converted into potassium chloride, 
tellurium tetrachloride, and bromine. The latter two sub- 
stances, being volatile, are driven off, and the last trace of 
tellurium can be expelled from the potassium chloride by 
heating in a current of hydrochloric acid gas. In this 
method potassium tellurium bromide is originally 
weighed, and later potassium chloride. It is thus 
possible to obtain a tellurium figure through the ratios of 
bromine, chlorine, and potassium, and to eliminate the 
possibility of an error in the weighing of tellurium, which 
may contain oxygen when precipitated from solution and 
dried. It also does not require the formation of insoluble 
silver bromide by double decomposition with this salt, a 
reaction to be avoided if possible, inasmuch as the tellurous 
acid formed by dissolving the salt in water tends to form 
insoluble silver tellurite which would contaminate to a 
greater or less extent the silver bromide formed. By this 
method of weighing potassium tellurium bromide and sub- 
sequently weighing potassium chloride any question of the 
ratio of tellurium and oxygen would be removed. 

Preparation of Material. Tellurium from Colorado. — 
Through the courtesy of Prof. C. W. Stoddart, a quantity 
of tellurium gold ore was obtained from the Clarissa 
Tunnel, Boulder County, Colorado. The ore is graphic 
tellurium containing about 3 per cent of gold and a little 
silver in a vein rock of quartz. 

The ore was extracted with hot nitrohydrochloric acid, 
the extract was converted into hydrochloric acid solution 
free from nitric by repeated evaporation with hydrochloric 
acid, after which sodium acid sulphite was added, and the 
impure tellurium precipitated. The dried precipitate was 
fused with potassium cyanide in order to separate the 
heavy metals and to allow of the separation of the sulphur 
and selenium from the tellurium. After extraction with 
water and filtration from the gold and other heavy metals, 
a current of air was passed through the solution, and the 
tellurium precipitated, the sulphur and selenium remaining 
in the cyanide solution. One hundred grms. of tellurium 
thus obtained were precipitated from the chloride solution 
by means of sulphur dioxide gas, after which it was con 
verted into basic nitrate. The re-crystallised basic nitrate 
was converted by ignition into the oxide. 



Atomic weight Te. 



Weight K^TeBre. Weight KCl. i. 
Series I. — Tellurium from Bohemia. 

233360 0-50779 127-31 

1-27372 0-27716 12732 

i'47573 0-32111 127-33 

1-65715 0-36059 127-33 

1-54006 0-33513 127-29 



Mean 127-32 

Series II. — Tellurium from Copper Ores. 
1-82810 0-39778 127-34 

1-87342 0-40765 127-33 

1-48045 0-32214 127-33 

2-24775 0-48911 127-31 



10. 


2-37899 


II. 


1-79926 


12. 


0-94102 


13- 


1-55357 


14. 


1-95038 


15- 


1-73248 


16. 


1-81923 



Mean 127-33 

Series IIL — Tellurium from Colorado. 

0-51767 127-31 

0-39146 127-41 

0-20476 127-33 

0-33806 127-31 

0-42440 127-31 

0-37698 127-33 

039586 127 32 



Mean 127-33 

Mean of the three series .. 127-33 



127-54 
127-54 
127-56 

12755 
127-51 

127-54 



127-56 
127-55 
12755 
12754 

12755 



127-54 
127-64 
127-56 

127-54 
127-54 

12755 
127-55 

127-55 
127-55 



Tellurium from Bohemia. — Fifty grms. of tellurium from 
the Transylvania gold ores were precipitated by sulphur 
dioxide from hydrochloric acid solution, fused with potas- 
sium cyanide to remove sulphur, selenium, and any heavy 
metals ; again precipitated from chloride solution by 
sulphur dioxide. It was then transformed into the basic 
nitrate, which was re-crystallised and ignited to oxide. 

Tellurium from Copper Ores. — A quantity of tellurium 
residues from the electrolytic tanks of the Baltimore Copper 
Smelting and Rolling Co. was treated in alkaline solution 
with grape-sugar. The tellurium obtained was purified by 
precipitation from chloride solution by means of sulphur 
dioxide ; this product was fused with potassium cyanide to 
separate it from sulphur, selenium, and the heavy metals, 
twice distilled in hydrogen, and after re-crystallisation as 
basic nitrate was converted to oxide. 

Potassium Bromide. — The potassium used was prepared 
from Kahlbaum's pure material. It was repeatedly crystal- 
lised, and in each crystallisation the first portions and last 
portion were rejected. 

Hydwbromic Acid. — The acid used was prepared from 
potassium bromide and sulphuric acid, the small amount 
of bromine formed being removed by means of phosphorus, 
and the resulting colourless acid repeatedly distilled. 

Preparation of the Double Bromide of Tellurium and 
Potassium. — The tellurium oxide was dissolved in hydro- 
bromic acid and the molecular proportion of potassium 
bromide added. The bright red anhydrous salt was 
crystallised from boiling solution, re-dissolved in pure water 
containing a small quantity of hydrobromic acid, and 
repeatedly crystallised from boiling solution. 

In order to remove the last traces of moisture and hydro- 
bromic acid, the salt was finely powdered and dried in 
vacuum desiccators over soda lime for a period of eight 
months. Tests made showed that the salt prepared in 
this manner is anhydrous. 

Procedure. — The double bromide was weighed into a 
porcelain boat. The boat was covered with a loosely 
fitting piece of glass, and placed in a tube of Jena glass. 
A current of chlorine was passed through the tube, and 
heat was applied immediately below the boat. A low tem- 
perature was maintained for a short time, after which the 
temperature was gradually raised. After conducting a 



I02 



Poisonous Gaseous Emanations of Ferro-sUicon. 



( Chemical News, 
I Feb. 25, igoj 



brisk current of chlorine over the salt for an hour, the 
chlorine was replaced by hydrochloric acid gas, and the 
boat and the salt heated for an hour longer. Treatment of 
the material with hydrochloric acid gas is essential after 
the treatment with chlorine. Small amounts of tellurium 
oxide are produced in the potassium chloride by the action 
of the oxygen of the air remaining in the tube on the 
tellurium chloride first formed by the action of the chlorine 
on the original salt. It is impossible to volatilise this 
oxide from the resulting potassium chloride by heating 
in chlorine alone, but with hydrochloric acid gas 
TeOa-zHCl is formed with the oxide, and is driven out of 
the boat. That any oxychloride is formed by heating 
tellurium tetrachloride in air or oxygen is highly improbable, 
and its doubtful existence will be shown in another place. 

All weighings were made on a balance constructed by 
Troemner, having a capacity of 200 grms. and a sensibility 
with a minimum load of one fifty-fifth of a mgrm. All 
weighings are reduced to zero and vacuum. The slight 
change in weight of the porcelain boats used was con- 
stantly watched and corrections duly made. The following 
atomic weights were used : — i. Bromine, 7996 ; chlorine, 
35-45 ; potassium, 3911. 2. The revised weights of the 
Atomic Weight Commission for 1909: Chlorme, 35'46; 
bromine, 79-92 ; potassium, 39095. 

It will be observed that the atomic weight of tellurium 
as given by use of 1909 figures for chlorine, bromine, and 
potassium appears as 12755, which figure the author con- 
siders to be very close to the true ratio for tellurium. — 
yournal of the American Chemical Society, xxxi., No. i. 



THE POISONOUS GASEOUS EMANATIONS OF 

FERRO- SILICON.* 
Being a Report of the Result of an Inquiry into 

THE Cause of Death of Five Rus.sian Immigrants 

AT Grimsby. 

The importance of a consideration of this subject has been 
recently emphasised by the deaths of five Russian immi- 
grants, who alone occupied the steerage of the s.s. Ashton 
during her voyage of some twenty-four hours from Antwerp 
to Grimsby, which latter place was reached on December 13. 
The ship carried a cargo of ferro-silicon, which was placed 
in the hold immediately underneath the fore between-deck 
hatchway accommodation occupied by the immigrants, 
which accommodation, by means of bulkheads, was shut 
oflf from the other part of the ship, except as regards the 
doors, which were under the control of the immigrants, 
and so in all probability were closed. The hatches above 
the accommodation were battened down and covered with 
tarpaulin, and the port-holes and ventilators were closed, 
so that if any gases emanated from the ferro-silicon below 
they would obtain easy access to the compartment occupied 
by the deceased above, and dilution could alone be effected 
by the possibility of the open doors. 

The evidence given at the inquest by the steward was 
to the eff^ect that the deceased appeared to be in good 
health on their arrival ; that the usual supper was served 
to them, which was also partaken of by the crew ; that 
two of tke immigrants, who were girls, had tinned food in 
a pelisse which appeared to be pickled cherries, whilst one 
of the two men had half a loaf of bread and some polony. 
The fifth passenger was a boy aged eleven, the two men 
were respectively thirty-five and thirty-two years of age, 
and the women nineteen and fifteen. No complaint was 
made of ilina'^s on the part of the deceased, but on visiting 
them on the Sunday morning the steward found one of 
the girls to be vomiting, which he attributed to sea- 
sickness. On visiting her later he found that she was 



* Communicated from the Laboratories of the Royal Institute of 
Public Health by the Principal, Professor William R. Smith, M.D., 
D.Sc, F.R.S Ed. Journal of the Royal Institutt of Public Hea th, 
January, 1909. 



dead, and upon calling the captain and with him making a 
further examination it was discovered that one of the men, 
the other girl, and the boy were also dead ; the second 
man was alive, but he shortly after expired on deck, to 
which he had been removed. There was evidence that 
the deceased persons had vomited, and that some of them 
had cried for drink, otherwise no complaint was apparently 
made. The boy and the man were found dead on the 
floor, the two girls were discovered dead in their bunks, 
and the remaining man was found sitting in his bunk. 

On the arrival of the ship at Grimsby she was boarded 
by the Port Medical Officer, Dr. W. Bulmer Simpson, 
who with commendable promptitude had the bodies re- 
moved to the mortuary, the ship disinfected, and retained 
in quarantine. 

Dr. Simpson, who made the post-mortem examination, 
deposed that he found the lungs in all cases, with but one 
exception, congested with dark venous blood ; that in that 
case one of the lungs was adherent to the chest-walls, 
whilst the other lung presented similar appearances t* 
those found in the other cases. There were also some 
patches of ecchymoses on the lung surfaces ; the intestines, 
both large and small, were empty, and that he had sent 
the stomachs of the several cases, with their contents 
properly secured, together with portions of the small intes- 
tines and two tins of apparently preserved cherries, to 
The Royal Institute of Public Health, London, for ex- 
amination. 

On Monday, December 14, 1908, these specimens were 
received at the Royal Institute, together with instructions 
that the examinations should be conducted with the view 
of determining the question as to whether cholera or 
ptomaine poisoning was the cause of death. 

The five stomachs and corresponding parts of the small 
intestines were properly tied up and contained in five 
separate receptacles, marked Nos. i, 2, 3, 4, and 5. The 
stomachs were found to be filled with a watery turbid 
liquid containing food-rests (cherries) and greyish-white 
flakes of mucus (especially in cases Nos. i and 5). The 
contents of the small intestines were less liquid than those 
found in the stomachs and had a greyish-yellow colour. 
The mucous membrane of the stomachs and of the small 
intestines showed a strong injection of the blood-vessels 
and was covered with mucus. 

From a pathological point of view, therefore, the cases 
did not suggest evidence of cholera, as the "rice-water" 
like appearance of typical cholera contents was not 
presented. 

Film preparations were made from the mucus flakes of 
the stomachs and intestines and these revealed amongst 
other bacteria, numerous vibrios (especially in Cases i 
and 5) in heaps, and even in " fish-in-stream " like arrange- 
ment, and thus the suspicion of cholera appeared to be 
justifiable. 

The efforts for isolating the vibrios in question were for 
a long time without result, as they apparently, for some 
reason or other, were considerably weakened, and conse- 
quently could not be isolated from the original gelatin- 
agar and peptone water cultures, but they were subse- 
quently isolated by means of sub-cultures from the second 
series of peptone water cultures, and even then only in 
Cases I and 2. These vibrios, which grew on gelatin and 
agar plates, in colonies indistinguishable from true cholera 
colonies, were subjected to a further examination. They 
gave the "cholera-red" reaction after twenty-four hours 
growth in peptone water, but tested with an agglutinating 
cholera-immune serum, they could not be agglutinated in 
a serum dilution of i in 100 within two hours, whilst in a 
control experiment the true cholera vibrios were aggluti- 
nated by the same cholera-immune serum in a dilution of 
I in 100 within a few minutes, and in a dilution of i in 500 
in thirty minutes. Pfeiffer's reaction, also carried out 
with the vibrio under examination, a true cholera vibrio, 
and a true cholera-immune serum on four guinea-pigs, 
gave negative results, the vibrio not being dissolved. The 
vibrio, however, was found to be pathogenic for |;uinea- 



Chemical News, ^ 
Feb. 26, 1909 



Poisonous Gaseous Emanations of Ferro-stlicon 



103 



pigs ; half a loop of the vibrio in i cc. broth intra-peri- 
toneally injected into guinea-pigs killed them within eight 
to ten days ; whilst one loop of the vibrio in i cc. broth 
intra-peritoneally injected, killed within three to four days. 
Thus it was proved that the vibrio isolated from the Grimsby 
cases, although closely resembling the cholera vibrio in its 
growth on media and giving the "cholera-red " reaction, 
and being pathogenic to guinea-pigs, was not the true 
cholera vibrio. 

Since Ruffer's investigations, in El Tor, it is known that 
from the intestines of patients suffering from various 
diseases (diarrhcea, dysentery, pneumonia, rheumatism), 
but who had never had cholera nor been in contact with 
with it, cholera-like vibrios may occasionally be isolated, 
and these five Grimsby cases furnish a confirmation of 
this statement. These cases are, therefore, of much 
interest, inasmuch as they prove the possibility of the 
existence of vibrios, closely resembling cholera vibrios, in 
the stomachs and intestines of presumably healthy persons. 

In response to requests from the Institute, the following 
were received from Dr. Simpson : — 

December 16 : Portions of the lungs, specimens of the 
blood, and a small quantity of urine of the deceased. 

December 17 : A sausage, some syrup, small bottle of 
preserved fruit, and a small quantity (about 6 ozs.) of ferro- 
silicon. 

December 19: A Winchester quart bottle of ferro-silicon. 

Whilst the bacteriological examinations for the cholera 
vibrio were being made, the samples of food sent, together 
with the sausage and the contents of the stomachs and 
intestines, were subjected to examination for the detection 
of the presence of a food poison, or of food poison pro- 
ducing bacteria, belonging to the group of the B. enteritidis 
and B. botulinus, but both anaerobic and aerobic cultures 
(Drigalski, Conradi, Endo, Malachite green plates, &c.), 
and the experiments on animals (mice, rats, guinea-pigs) 
gave negative results. As the deaths had been of such a 
sudden nature, portions of the viscera, as well as the pre- 
served fruit, sausage, &c., were chemically examined for 
alkaloids, arsenic, antimony, and the metallic poisons, but 
with negative results. Suspicion was now directed to a 
portion of the cargo as being a possible cause of death, 
owing to the poisonous gases which it was known to 
evolve. As the result of this, the portions of the lungs, 
blood, and urine were examined for arsenic^ but without 
result. The blood was also spectroscopically examined 
for carbon monoxide, with like negative results. 

With reference to the gases emanating from ferro-silicon 
the following experiments on animals were undertaken, 
viz. : — 

1. A small quantity of the ferro-silicon received on 
December 17 was placed in the bottom of two glass jars, 
being moistened in the one case, but left dry in the other. 
Into each of these jars a mouse was then placed, resting 
on a piece of wire-gauze placed some distance above the 
substance. Both mice showed marked symptoms of 
dulness and somnolency, and the one before death distur- 
bances of movement. The mouse over the moistened 
ferro-silicon died in four and a-half hours, whilst the one 
over the dry substance lived. 

2. Four mice placed in a larger jar over moistened ferro- 
silicon also died within from six to ten hours. 

3. Four guinea-pigs when placed over the moistened 
substance under similar conditions, died within ten hours. 

4. A guinea-pig placed over a quantity of dry ferro- 
silicon also died, but this was possibly accounted for by 
the ferro-silicon becoming moistened with the animal's 
urine. 

All these animals exhibited the symptoms previously 
mentioned, together with those of retching. 

With reference to the post-mortem examination, the only 
common abnormal feature observed was congestion of the 
lungs, such as is usually seen in cases of death by suffoca- 
tion. In a few cases pneumonia-like patches in the inferior 
lobes of the lungs were found. Two of the mice, however, 
ghowed enlargement of the spleen. The other organs of 



all the animals exhibited no marked features. Micro- 
scopically, the lungs showed hyperaemia and albuminous 
exudation into the alveoli, whilst in the other organs no 
remarkable histological alterations could be noticed. 

These animal experiments prove that ferro-silicon, when 
moist, readily evolves gases which are fatal to life. This 
substance is a coarse metallic powder, which, under ordinary 
circumstances, possesses no particular odour, but if con- 
fined, powdered, or moistened, a distinct phosphorous 
odour can be detected. It is manufactured by heating a 
mixture of iron-ore, quartz, coke, and lime in an electric 
furnace, and is used by steel-makers as a convenient 
method for the addition of silicon to certain grades of 
steel. A little consideration will give some indication of 
the nature of the poisonous gases likely to be formed when 
this product is moistened. Many minerals contain phos- 
phoric acid and arsenic. Consequently, when such a mix- 
ture, as above described, is strongly heated, phosphides, 
arsenides, carbides, and silicides may be formed, and 
these may, under certain conditions, evolve phosphoretted 
hydrogen, arseniuretted hydrogen, acetylene, and silicon 
hydride. 

In order to determine which of the above gases is 
mainly evolved when ferro-silicon is moistened, the fol- 
lowing experiments were made : — 

(a) Two hundred grms. of the powdered and moistened 
substance were placed in a horizontal glass tube, 19 in. 
long and i in. in diameter. This tube was connected with 
another tube about 11 in. long and a half inch in diameter, 
and filled with small pieces of potassium hydrate in order 
to absorb any sulphuretted hydrogen. Air was then gently 
drawn through the tube for about three hours and allowed 
to pass through a 10 per cent solution of silver nitrate con- 
tained in a De Koninck absorption apparatus. A dark 
precipitate was immediately produced in the silver solution 
and at the end of the period was considerable in amount. 
This precipitate might be due to all or any one of the 
above-mentioned hydrides. 

{h) Experfment (a) was repeated, with the exception 
that the potassium hydrate tube was removed and am- 
moniacal cuprous chloride solution substituted for the 
silver nitrate. As no precipitate was formed in the copper 
solution it is evident that acetylene is not formed under 
these conditions. 

(c) Experiment (a) was repeated, but in this case the 
gases were passed through nitric acid. The acid solution 
was evaporated almost to drynees, hydrochloric acid added, 
and the mixture evaporated to complete dryness. The 
addition of hydrochloric acid and subsequent evaporation 
to dryness was repeated and the residue dissolved in 
distilled water, when no trace of insoluble silica was found. 
Silicon hydride is, therefore, not evolved from moistened 
ferro-silicon at ordinary temperatures. Having excluded 
acetylene and silicon hydride from the gaseous mixture, 
there remains the possibility of phosphoretted and arseni- 
uretted hydrogen. 

{d) Some of the silver solution obtained in Experiment (a) 
was then filtered and the filtrate, which would contain 
arsenic (if present in the gases) as arsenic acid, was intro- 
duced into a Marsh-Berzelius apparatus, with the result 
that a slight mirror was obtained after prolonged heating. 
Some of the precipitate was then introduced into the 
apparatus, when the characteristic phosphorus flame was 
immediately produced, being most marked, and this, in 
spite of the facts that the heating of the glass tube was 
continued, which would tend to decompose phosphoretted 
hydrogen, and that the flame was burning at the end of a 
tube not furnished with a platinum jet. It is thereiore 
evident that although arseniuretted hydrogen is produced 
in small quantities, the chief gas evolved is undoubtedly 
phosphoretted hydrogen, a gas which is stated to be so 
poisonous that 002 per cent of it in air is fatal to smal 
animals within half an hour. 

The result, therefore, of the enquiry into the cause o 
death of the five Russian immigrants on board the s. 
Ashton is that they died from the effects of gaseous eip^n^ 



104 



Formation and Reactions of Imino-compounds. 



i Chemical News, 
I Feb. 26, 1909 



tions from the cargo (ferro-silicon) mainly attributable to 
the presence of phosphoretted hydrogen. 

This investigation is of great scientific interest, as pos- 
sibly it is the first occasion in this country in which deaths 
have been known to be attributable to this cause. 

As ferro-silicon is a substance the manufacture of which 
on a large scale has only been undertaken within the last 
few years, references in scientific literature to the poisonous 
nature of its gaseous emanations are very scanty. 

The Board of Trade journal, August 22, 1907, contains 
a reference to an enquiry made by Professor Cronquist, of 
Stockholm, into the cause of death of four persons on 
board the s.s. Olaf Wijk, which was carrying ferro-silicon 
as a part of its cargo, who gave as his opinion that death 
had been caused by the poisonous gases given off by this 
material, but he does not appear to have specified what 
gas or gases produced the fatal results. 

On March 15, 1906, Bahr and Lehnkering {Vierteljahrs- 
schrift fiir gerichtliche und oeffentliches Sanitdtswesen, 
xxxii., pp. 123-9), published the results of their examina- 
tion of the bodies of two children, aged two and a-half 
and four and a-half, who had died on a Rhine steamer on 
a voyage between Mannheim and Duisberg. This vessel 
was carrying about 40 tons of ferro-silicon. These children 
had slept in a cabin situated just above the material, and 
it had been found necessary to light the stove. An ordinary 
wooden deck separated the children from the cargo, and it 
seems very probable that the stove had drawn the gases 
from the hold into the cabin. The symptoms before death 
were vomiting, thirst, and somnolency. 

The post-mortem examination revealed no sufficient 
pathological, or anatomical, reason for death, the only 
abnormal appearance being congestion of the lungs. 
Chemically, no positive evidence of the presence of 
poisonous substances was obtained. This, of course, may 
be explained by the probability that phosphoretted hydrogen, 
which Lehnkering showed was given off in large quantities 
by the ferro-silicon of the cargo when moistened, is readily 
oxidised, and that phosphoric acid, the product of its 
oxidation, is a normal constituent of the human body. 
These authors also mention various deaths of persons on 
steamers carrying ferro-silicon, viz., one girl of fifteen 
years, one woman, one man, and a child of two years, 
which were most likely caused by phosphoretted hydrogen 
evolved by this substance, but owing to the absence of 
knowledge of the dangerous nature of the cargo, were not 
at the time so certified. Very little work appears to have 
been done respecting the physiological and pathological 
effect of phosphoretted hydrogen. The earliest reference 
appears to be in Eulenberg Die Lehre von den gijtigen 
Gasen., 1865, p. 424, who says that 0-25 per cent of this 
gas in air is fatal to man. 

In Archiv. f. exp. Path. u. Pharm., xv., p. 438, is an 
abstract of a dissertation in Russia by " Brilliant," on the 
effects of this gas on various animals, and in vol. xxvii., 
p. 314, of the same journal appears a rather more detailed 
account of similar work performed by Schulz. 

With reference to the toxicity, these authors state that 
o*459 per cent PH3 in air killed rabbits within about 
eighteen minutes. A striking but regular feature being 
that the animals soon became somnolent, and that ataxis 
and other disturbances of the movements were observed. 
Retching or vomiting was an almost invariable symptom, 
and the animals died finally in a state of stupor and 
asphyxia. The postmortem of these animals showed no 
visible alteration of the elements of the blood, the cerebrum, 
and the spinal cord, but a degree of congestion of the 
intestinal organs and a high degree of hyperaemia in the 
lungs, partly accompanied with ecchymoses. Micro- 
scopically, the examination revealed congestion of the 
capillaries and albuminous exudation in the alveoli, but 
no noteworthy alterations in the other organs. 

These post-mortem appearances furnish a confirmation 
of what was found in the animals experimented upon at 
the Royal Institute. 
The pathological effects of such poisonous gases as 



phosphoretted hydrogen and the like are at present so 
little understood that it has been determined to undertake 
further experiments in connection with this subject. 

I cannot conclude this report without recording my great 
indebtedness to Dr. Hermann Dold, the Harben Demon- 
strator of Bacteriology and Comparative Pathology, and 
Dr. Charles E. Harris, the Demonstrator of Chemistry, 
upon whom the investigations mainly devolved. 



PROCEEDINGS OF SOCIETIES. 

CHEMICAL SOCIETY. 
Ordinary Meetiiig, February ^th, igog. 

Sir William Ramsay, K.C.B., F.R.S., President, 
in the Chair. 

(Concluded from p. 92). 
31. ^'The Formation and Reactions of Imino-compounds. 
Part VIII. The Formation of Methyl Derivatives of 
2-Phcnyl-i : ^-naphthylenediatnine from the three Tolyl- 
acetonitriles." By Stanley Robert Best and Jocelyn 
Field Thorpe. 

Previous experiments have indicated that the trans- 
formation of a benzenoid imino-nitrile into a derivative of 
I : 3-naphthylenediamine by the action of cold concen- 
trated sulphuric acid is hindered if a methyl group is in 
the meta-position with respect to the carbon atom at which 
ring formation must take place. Experiments have now 
been made which furnish further instances of this hindering 
action. 

The three tolylacetonitriles readily undergo intra- 
molecular condensation, forming li-imifio-a-cyano-ay-di-o- 
tolylpropane (I.), 0- imino-a-cyano-a'^-di-m- tolylpropane 
(11.), and t3-imino-a-cyano-ay-di-p-tolylpropane (III.) : — 



Me CH2 
/\^\ C:NH 



Me 



CH2 
/^^\ C:NH 



CN 



CH-C6H4Me(o) 



\/ 



CHC6H4Me(ff») 



CN 



II. 



CH2 
/\/^\ C:NH 

Me II I CH-C6H4Me(/) 

CN 

III. 

and when these compounds are treated with cold concen- 
trated sulphuric acid they are converted into the sulphates 
of 6-o-tolyl-i-fnethyl-s '• ynapthylenediamine (IV.), 6-m- 
tolyl-2-methyl-s : j-naphthylenediamine (V.), and j-p-tolyl- 
2-methyl-6: 8-naphthylenediamine (VI.) respectively : — 



Me 



NH 



NH2 

C6H4Me(o) 



Me 



NH 



NH2 
C6H4Me(m) 



IV. 



/\/\ 



NH, 



Mev 



C6H4Me(^) 



NH2 
VI. 



The yields of the naphthalene derivatives from the three 
iminonitriles are in accordance with previous observations. 
Thus the meta-derivative (II.), from which ring formation 



Chemical Nbws, 1 
Feb. 26, 1909 I 



Ester ification Constants of Substituted Acrylic Acids. 



105 



is shown by the oxidation of the naphthalene derivative to 
4 methylphthalic acid to take place in the para-position 
with respect to the methyl group, gives 80 per cent of the 
theoretical quantity of 6-Mj-tolyl-2-methyl-5 : 7-naphthyl- 
enediamine (V.), whereas from the ortho- and para-deriva- 
tives (I. and (III-), from which ring formation has to take 
place in the meta-position with respect to the methyl 
group, scarcely more than 10 per cent of the naphthalene 
derivatives {IV. and VI.) are obtained under the same ex- 
perimental conditions. The preparation and properties of 
the pyrimidine derivatives derived from the three tolyl- 
acetonitriles were described. 

32. " The E^ect of Contiguous Unsaturated Groups on 
Optical Activity. Part I." By Thomas Percy Hilditch. 

The chemical and physical behaviour of organic sub- 
stances containing adjacent unsaturated groups has fre- 
quently been observed to be irregular, and, as is well 
known, the optical properties of refractive index and 
magnetic rotatory power exhibit anomalies in such cases. 
The present work is the first part of an investigation 
designed to find out if optical activity is subject to the 
same influences. From the collected observation of different 
workers, in the cases of terpene derivatives, optically active 
aromatic substances and optically active esters possessing 
conjugated unsaturated systems, the author showed that 
in many, but not in all. Instances a pronounced increase 
in molecular rotatory power takes place. Further, from 
observations on the camphorates and camphor-J-sul- 
phonates of a number of phenolic or amino-derivatives of 
substances containing a benaenoid residue adjacent to an 
ethylenic or carbonyl group, it is found that : — 

1. Conjugation is accompanied by abnormal optical 
activity. 

2. The effect reaches a maximum when the conjugated 
system is nearest to the asymmetric carbon atoms. 

3. The effect is lessened as the proximity of the un- 
saturated groups to one another is lessened. 

4. The effect is decreased, and sometimes completely 
destroyed, if a saturated group is interposed between the 
conjugated and asymmetric systems. 

33. " The Miscibility of Solids." By Ernest Van- 
stone. 

While working on solid solutions with camphor, the 
author was led to develop the present theory. The ex- 
planation of the miscibility of solids is suggested by the 
Pope and Barlow theory, and may be stated as follows : — 
Two substances will show the greatest degree of misci- 
bility, whose assemblages of spheres of atomic influence 
possess similar marshalling, and are capable of being par- 
titioned into units possessing almost equal volumes, the 
volumes being the molecular domains. 

This explanation applies to the miscibility of the 
elements and of compounds, both organic and inorganic. 

The degree of miscibility of two elements depends on the 
closeness of agreement between the atomic volumes, and 
also on their valency values, and this accounts for the 
great tendency of the elements to form mixed crystals. 

Where a difference in valency volumes exists, a slight 
expansion of the spheres composing the substance of lower 
valency volume causes the volume of the molecular unit 
to approximate closely to that of the substance of higher 
valency volume. 

The freezing-point curves for camphor and borneol- 
benzoin and benzil, and menthol and menthone have been 
obtained. The first pair of compounds forms solid solu- 
tions in all proportions, borneol raising the freezing-point 
of camphor continuously. Benzoin and benzil show a 
curious behaviour, as the curve has two eutectic points 
with an intermediate horizontal portion. The curve for 
menthol and menthone appears to be continuous with a 
minimum point. 

34. " Esterification Constants of Substituted Acrylic 
Acids." Part III. By John Joseph Sudborough aud 
Tames Mylam Gittins. 

The constants at 15°, using methyl alcohol with hydrogen 



chloride as catalyst, have been determined for the following 
acids: cvc/o Hexanecarboxylic, phenylacetic, '>- and /3- 
phenylpropionic, T'-phenyl/j-butyric, ^-phenyl-H-valeric, 
furfurylpropionic, phenylbenzylacetic, undecylenic, oleic, 
elaidic, erucic, brassidic, phenyl- ■}-)' crotonic, allylacetic, 
soibic, cinnamylideneacetic, hydrosorbic, cinnamenyl- 
propionic, S-phenylethylidenepropionic, phenylpropylidene- 
acetic, aJ-oleic, a//o cinnamic, and tetrolic. The results 
confirm the conclusions previously drawn (Trans., 1905, 
Ixxxvii., 1840; 1907, xci., 1033). 

The constants for aJ-unsaturated acids are remarkably 
low when compared with those for the corresponding 
saturated acids. dy-Unsaturated acids have constants 
somewhat larger than those for their saturated analogues, 
and double bonds which are still further removed from the 
carboxylic group have very little effect, so that there is 
practically no difference between the constants for the 
unsaturated and the corresponding saturated acid. 

The effect of the reduction of benzoic to cyclohexzne- 
carboxylic acid is remarkable, the constant being raised 
from 025 to 193. 

A triple linking in the a/3-position has much the same 
effect as a double bond in the same position, and conjugate 
ethylene Unkings have a somewhat greater retarding effect 
than an oJ-double linking. 

35. " Brazilin, Hematoxylin, and their Derivatives. 
Part X. The Constitution of Trimethvlbrazilone, of a- 
and B-Anhydrotrimethylbrazilone, andoj the corresponding 
Derivatives of Hctniatoxylin." By William Henry 
Perkin, jun., and Robert Robinson. 

The authors described in detail the properties of the 
derivatives mentioned in the title with the object of proving 
that the constitutional formulas assigned to them in the 
previous parts of this research are correct. 

36. "The Preparation of Disulphides. Part III. The 
Nitrobenzyl Disulphides." (A Correction). By Thomas 
Slater Price and Douglas Frank Twiss. 

In a recent communication on the nitrobenzyl disulphides 
[Trans., 1908, xciii., 1401), the statement was made that 
" the three disulphides obtained in the course of this in- 
vestigation have not been isolated before." This statement 
is erroneous so far as the ortho- and meta-disulphides are 
concerned, but it does not affect the subject-matter of the 
paper cited, since a new method of preparation of these 
disulphides is there given. 

Jahoda (Monatsh., 1890, x., 874) claimed to have pre- 
pared di-o-nitrobenzyl disulphide (this nomenclature is to 
be preferred to o-nitrobenzyl disulphide), but Gabriel and 
Stelzner (Ber., 1896, xxix., 161) showed that Jahoda's 
product was really the mercaptan. They prepared the 
o-disulphide and found it to consist of yellow crystals 
which melted at 112 — 113°, these properties agreeing with 
those found by Gabriel and Posner {Ber., 1895, xxviii., 
1025) and Cassirer [Ber., 1892, xxv., 3029). In 1901, 
Blanksma {Rec. trav. chim., 1901, xx., 137) also prepared 
di-o-nitrobenzyl disulphide (this compound is not mentioned 
in Abstr., 1901, Ixxx., i., 461) and found that it melted at 
no'. This melting-point agrees with that observed by 
the authors (io95°), but they also find that on repeated 
crystallisation from alcohol the crystals become almost 
colourless, possessing only a slight yellow tinge. 

Di-OT-nitrobenzyl disulphide has been prepared by Lutter 
(Ber., 1897, xxx., 1069) by oxidation of the corresponding 
mercaptan with iodine, and is described as consisting of 
yellowish white crystals melting at 103 — 104". The 
melting-point agrees with that observed by the authors, 
but when pure the substance is almost colourless ; indi- 
vidual crystals appear colourless, but in bulk they possess 
a faint yellow tinge. 

Strakosch (Ber., 1872, v., 692) claims to have obtained 
di-^-nitrobenzyl disulphide. The melting-point given, 
89°, is quite different from that observed by the authors 
(i26'5°), and does not correspond with the melting-points 
of the 0- and m-compounds. The analytical results are 
also not satisfactory, 1972 per cent of sulphur being found 



io6 



Formation of Heterocyclic Compounds. 



I Chemical News, 
I Feb. 26, 1909 



instead of i9*o5 per cent. Evidently the compound pre- 
pared by Strakosch was not the disulphide, and the authors 
are engaged in repeating his experiments. The pure sub- 
stance possesses a colour similar to that of the m-disulphide. 

37. "Derivatives of Naphthaceneqniiione." Part III. 
By DorothV Harrop, Roland Victor Norris, and 
Charles Weizmann. 

In continuation of previous work {Trans., 1907, xci., 
1588), the authors have prepared a further series of naphth- 
acenequinone derivatives. 

38. " The Nature of Ammoniacal Copper Solutions. 
Part II. The Solubility of Cupric Hydroxide in Am- 
moniacal Sulphate Solutions." By Harry Medforth 
Dawson. 

With the object of supplementing the information 
already obtained concerning the nature of ammoniacal 
solutions of copper salts (compare Dawson, Trans., 1906, 
Ixxxix., 1666 ; 1900, Ixxvii., 1239), the author has measured 
the solubility of cupric hydroxide in ammoniacal solutions 
of ammonium and sodium sulphates, and of barium and 
sodium hydroxides. 

Cupric hydroxide does not dissolve directly in pure am- 
monium sulphate solutions, and this is an indication that 
cupridiammmonia compounds either do not exist or are 
not readily formed. In presence of ammonia the hydroxide 
dissolves readily, and ammonia therefore appears to be 
the primary cause of the solution process, cupritetra- 
ammonia hydroxide being thereby formed. This then 
reacts with the ammonium sulphate in the solution, the 
action consisting in the partial displacement of the 
ammonia from the sulphate by the stronger cupri-ammonia 
base, a condition of equilibrium being set up corresponding 
with the scheme : — 
Cu-4NH3(OH)2+(NH4)2S04^Cu-4NH3S04+3NH40H. 

The solubility data are consistent with this view. 
From a consideration of the quantities of ammonia which 
are necessary to dissolve cupric hydroxide in such quantity 
that the resulting solution contains copper and sulphate in 
equivalent proportions, the conclusion is drawn that 
optically clear solutions, prepared by adding ammonia 
(not in large excess) to copper sulphate solutions, are 
supersaturated with respect to cupric hydroxide. When 
such solutions are shaken with cupric hydroxide, a diminu- 
tion in the copper concentration is actually observed. 
The deposited copper is supposed to be present in the 
original solution in the form of colloidal hydroxide. 

The new observations are in agreement with the author's 
previous determinations of the chemical dissociation in 
ammoniacal solutions of copper salts on the basis of 
distribution measurements. 

39. " The Action of 3-Rays ot Photosensitive Solutions." 
By Otto Flaschner. 

The analogy between the action of light and that of 
i^-rays on certain chemical reactions was pointed out and 
instanced in the case of two photosensitive solutions. 
The potential of an AgBr/KBr electrode rises under the 
influence of /^-rays, and falls when the latter disappear. 
The higher the initial potential the more sensitive is the 
electrode towards light and .-i-rays. 

The Eder's actinometric solution was the second type 
to be examined, and this is also influenced by J-rays. 

40. " The Rusting of Iron." By Gerald Tattersall 
Moody. 

In the experiments described by Tilden {Trans., 1908, 
xciii., 1356), the author has lost sight of the well-known 
fact that commercial iron and steel invariably contain 
foreign substances, notably sulphur compounds, which on 
exposure to air and water at once furnish free acids. The 
rusting observed in Tilden's experiments, in which carbonic 
acid was excluded, was a result primarily of interaction 
between acids, formed by oxidation of sulphur compounds 
and other foreign constituents capable of furnishing acids 
on reaction with water and oxygen, and iron, the resulting 



ferrous salt being subsequently oxidised with production 
of rust. 

Tilden's experiments conclusively show that commercial 
iron after treatment with chromic acid no longer rusts in 
presence of water and oxygen, but the inactivity is wrongly 
attributed to the chromic acid rendering the iron " passive." 
The true explanation of the inhibitive effect of chromic 
acid is that it removes from the surface of the iron those 
constituents which would otherwise subsequently yield 
acids on exposure to water and oxygen. That Tilden's 
view that the iron is rendered passive is incorrect is con- 
clusively shown by the readiness with which the iron rusts 
as soon as normal air containing carbonic acid or any 
other acid is admitted. 

Tilden further states that after immersion for years of 
iron in dilute chromic acid, he has observed " no sign of 
rust or of dissolution of the iron either by change of colour 
or the formation of precipitate on adding excess of 
ammonia." In this connexion it must be pointed out 
that ferric hydroxide is readily dissolved by chromic acid, 
so that visible change could not be expected. Moreover, 
dilute solutions of iron in chromic acid do not afford a 
visible precipitate or a change of colour on addition of 
excess of ammonia. If, however, the solution is filtered 
after addition of ammonia, ferric hydroxide in appreciable 
quantity remains on the filter paper, and the dissolution of 
the iron is thereby made evident. 

41. " The lodobenzenemonosulphonic Acids." Part I. 
By Mary Boyle. 

An account was given of the preparation and properties 
of X : 4 : 6-, 1:3:4-, 1:3:5-, and 1:2: ^-di-iodobenzene- 
sulphonic acids ; also of i : 2 : 3 : 5, 1:2:4:5, and 1:2:4: 
6-tri-iodobenzenesulphonic acids. The acids were mostly 
prepared from the appropriate aminosulphonic acids by 
introducing iodine by means of iodine chloride and subse- 
quently displacing the amino-group by iodine by the diazo- 
reaction. 

It is noteworthy that all the iodo-diazo-sulphonates are 
coloured compounds, varying from very pale yellow in the 
case of the i : 4-acid to bright yelljw in the case of the 
tri-iodo-acids. 

The acids are all readily soluble in water, and several 
crystallise well, especially in presence of mineral acid. 
They furnish well-defined salts, which are only sparingly 
soluble in water. The sulphonyl chlorides crystallise well. 

42. " Contributions to the Chemistry of the Terpenes. 
Part IV. The Oxidation of Pinene with Mercuric Acetate." 
By George Gerald Henderson and James Watson 
Agnew. 

By the action of aqueous mercuric acetate at the 
ordinary temperature, pinene is conveited into sobrerol, 
CioHi6(OH)2, a compound formerly prepared by oxidising 
pinene with moist oxygen in sunlight, and sobrerol is 
oxidised to a hydroxyketone, CioHi5(OH)0, when heated 
with the same reagent. The hydroxyketone is reduced to 
sobrerol when dissolved in moist ether and treated with 
sodium, and it yields carvacrol on reduction with aqueous 
hydriodic acid in the cold. When heated for a short time 
with anhydrous oxalic acid, it yields carvone together with 
some carvacrol, and when it is oxidised with an acidified 
solution of potassium permanganate, terpenylic acid is 
obtained. Hence it is concluded that the hydroxyketone 
is 8-hydroxycarvotanacetone. 

Sobrerol can also be prepared by the action of mercuric 
oxide on a cold solution of pinene in acetic acid, whilst 
if the solution is heated, the oxidation product is the 
hydroxyketone. 

43. "Formation of Heterocyclic Compounds. Part I. 
iPhenylpyrrolidine-2: 5-dicarboxylic Acid from Adipic 
Acid." By Henry Rondel Le Sueur. 

The methyl or ethyl ester of r-phenylpyrrolidine-2 : 5-di- 
carboxylic acid is readily obtained by the action of mono- 
ethylaniline on the corresponding methyl or ethyl ester of 
aa'-dibromoadipic acid. 

i-Phenylpyrrolidine-2 : ^-dicar boxy lie acid is crystalling, 



Chemical News, » 
Feb. 26, 1909 I 



Elements of Physical Chemistry, 



107 



and decomposes at 252° ; it is readily obtained by hydro- 
lysis of its ethyl ester. 

44. " The Influence of Solvents on the Rotation of 
Optically Active Compounds. Part XIV. Ethyl Tartrate 
in Benzaldehyde and in Quinoline." By Thomas Stewart 
Patterson and David Paterson McDonald. 

The influence of benzaldehyde and of quinoline as 
solvents on the rotation of ethyl tartrate was described. 



PHYSICAL SOCIETY. 
Annual General Meeting, February 12th, igog. 

Dr. C. Chree, F.R.S., President, in the Chair. 

The Secretary read the Reports of the Council and the 
Treasurer, which were adopted : — 

Report of Council. 

Since the last Annual General Meeting, ten Ordinary 
Science Meetings, two informal Meetings, and two Special 
General Meetings of the Society have been held. Of these, 
eleven were held at the Royal College of Science ; one, 
that on March 27th, at the Northampton Institute, by in- 
vitation of Dr. R. M. Walmsley ; one, that on October 
23rd, at the National Physical Laboratory, by invitation 
of Dr. R. T. Glazebrook, F.R.S. ; and one, that on 
November 13th, at University College, by invitation of 
Prof. F. T. Trouton, F.R.S. The average attendance at 
the meetings has been 61 as compared with 58 during the 
preceding year. 

The Fourth Annual Exhibition of Apparatus by manu- 
facturers was held on December nth, when the attendance 
of Fellows and Visitors amounted to about 300. Greater 
advantage is now being taken of this event by exhibitors, 
and the attendance this year was much larger than 
hitherto. 

Certain alterations to the Articles of Association have 
been introduced, more particularly in regard to the election 
of the Council. A copy of the revised Articles has been 
forwarded to every Fellow of the Society. 

The number of Ordinary Fellows now on the roll, as 
distinct from Honorary Fellows, is 430, a decrease of 7 on 
the number last year ; 12 new Fellows have been elected. 
There have been five resignations ; the names of three 
Fellows have been struck off the list for non-payment of 
subscriptions ; and the Society has to mourn the loss by 
death of two Honorary Fellows, namely, H. Becquerel 
and E. Mascart ; also one of their Past-Presidents, Prof. 
W. E. Ayrton, one of their Secretaries, Prof. W. Cassie, 
and nine other Ordinary Fellows, namely, Lord Blythswood, 
Mr. S. Hall, Prof. A. S. Herschel, Mr. S. Joyce, Mr. 
F. J. M. Page, the Earl of Rosse, Capt. J. H. Thomson, 
Mr. J. F. W^alker, and Dr. W. E. Wilson. 

Report 0/ the Treasurer for the Year igo8. 

After the temporary boom of igo7 has succeeded another 
period of depression. It has been almost impossible, in 
spite of strenuous efforts, to collect any arrears of sub- 
scriptions, the amount under this head standing at ;£"4 4s. 
as compared with £^^ 12s. in igo7. Only nine new 
Fe'lows have paid entrance fees as compared with 27 in 
1907, and the amount from composition fees is unusually 
small. In other respects there is little change in the 
position or expenditure of the Society, except that last 
year's printing bill was unusually heavy, and the balance, 
allowing for liabilities, is slightly reduced in consequence. 
The provision of refreshments at the meetings has entailed 
a small additional outlay, but the catering has been carried 
out most economically, and the total expense for 1908 is 
little more than that for the exhibition of apparatus alone 
in 1907. 

The following were elected as Honorary Fellows of the 
Society : — R. Benoit, Julius Thomsen. 

The following Officers and Council were elected for the 
ensuing year : — 



President— C. Chree, Sc.D., F.R.S. 

Vice-Presidents — Those who have filled the Office of 
President together with W. Duddell, F.R.S. ; Prof. A. 
Schuster, Ph.D., F.R.S. ; S. Skinner, M. A. ; W. Watson, 
D.Sc, F.R.S. 

Secretaries— W. R. Cooper, M.A. ; S. W. J. Smith, 
M.A., D.Sc. 

Foreign Secretary — Prof. S. P. Thompson, D.Sc, 
F R S 

Treasurer— Fioi. H. L. Callendar, M.A., F.R.S. 

Librarian— W. Watson, D.Sc, F.R.S. 

Other Members of Council — A. Campbell, B.A. ; W. H. 
Eccles, D.Sc. ; A. Griffiths, D.Sc. ; J. A. Harker, D.Sc. ; 
Prof. C. H. Lees, D.Sc, F.R.S.; T. Mather, F.R.S. ; 
A. Russell, M.A., D.Sc. ; Prof. E. Rutherford, D.Sc, 
F.R.S. ; F. E. Smith ; R. S. Whipple. 

The President then delivered an Address. 

He began by referring to the loss which the Society had 
sustained through the deaths of their ex-President Prof. 
Ayrton, and their Honorary Secretary Prof. Cassie. He 
referred to the assistance given to the Council by Mr. 
H. M. Elder, who discharged the duties of Secretary sub- 
sequent to Prof. Cassie's death until the appointment in the 
autumn of his successor, Mr. S. W. J Smith. He spoke 
of the popularity of the Exhibition of Instruments, much of 
the success of which must be attributed to the Senior 
Secretary, Mr. W. R. Cooper and to the Physics Depart- 
ment of the Imperial College of Science and Technology. 
One of the incidents of the year had been the revision of 
the Articles of Association by the Council, whose altera- 
tions had been confirmed at statutory meetings. The 
President then proceeded to give an account of some work 
he had recently been engaged in, in connection with the 
reduction of the magnetic observations of the National 
Antarctic Expedition of 1902-4. This referred to an inter- 
comparison of simultaneous records of magnetic distur- 
bances obtained m the Antarctic, and at the Observatories 
of Kew, Falmouth, Colaba (Bombay), Mauritius, and 
Christchurch (New Zealand). He exhibited a number of 
lantern-slides showing the sudden commencement of some 
magnetic storms, and the forms of some special types of 
disturbance observed in the Antarctic Some results were 
given as to the directions and intensities of the disturbing 
forces to which the disturbances recorded at the different 
stations might be attributed. 



NOTICES OF BOOKS. 

The Elements of Physical Chemistry. By J. Livingston 
R. Morgan, Ph.D. Fourth Edition. New York: John 
Wiley and Sons. London : Chapman and Hall, Ltd. 
1908. 
This is one of the best elementary text-books on physical 
chemistry in circulation and should be put in the hands of 
every student of chemistry. Considerably shorter than the 
classical works on the subject, it covers the whole of the 
theory of the science in one volume, and while making no 
pretensions to being a work of reference it is sufficiently 
detailed for all the purposes of a first year student. The 
practical applications of physical chemistry are constantly 
pointed out, and the author's aim has been above all to 
make his readers so thoroughly conversant with the method 
of reasoning and the results obtained that they can readily 
use their knowledge as a tool in their own work. Many 
numerical results are discussed in the text and an abstract 
principle is hardly ever stated without being followed by 
actual experimental data from which the student is recom- 
mended to perform the calculations in question. More- 
over, at the end of the book a collection of problems with 
answers is given to help more particularly the student who 
is working alone. The mathematics employed have been 
made as simple as possible, and even students who have 
had no higher mathematical training will find it com- 
paratively easy reading. 



io8 



Meetings for the Week. 



I (^HEMfcAL News, 
[ Feb. 26, 1909 



CHEMIC/^L NOTICES FROM FOREIGN 
SOURCES. 



NoTi. — All degrees of temperatnre are Centipede unless otherwise 
expressed. 

Comptes Rendus Hebdomadaires des Seances de VAcademie 
des Sciences, Vol. cxlviii., No. 3, January 18, igog. 
General Method of Preparing Trialkylacetic Acids. 
— A. Haller and Ed. Bauer. — The trialkylacetophenones 

/^ 
of general formula CeHj.CO.C^Ri , when heated with 

\Rii 
sodamide in a neutral solvent, such as benzene and its 
homologues, split up quantitatively, yielding the amides of 
trialkylacetic acids and an aromatic compound (hydro- 
carbon). The equation is — 

CeHj.CO.C^R' ^NaNHz + HaO- 
\Rii 

= C6H3 » H^NXO— C(-Ri +NaOH. 
\R" 

The amides may readily be converted into acids by the 
action of sodium nitrite and sulphuric acid or of nitrosyl 
sulphate. The trialkylacetic acids thus formed are 
generally mobile liquids, with an odour only slightly 
resembling that of ordinary fatty acids. With the excep- 
tion of pivalic acid, they are all nearly insoluble in water 
and can be distilled at the ordinary pressure without 
decomposition. 

Rapid Preparation of Calcium Phosphide for the 
Production of Phosphoretted Hydrogen. — C. Matignon 
and R. Trannoy. — At a faint red heat, aluminium powder 
readily reduces tricalcic phosphate, the equation being 
3(P04)2Ca3-»-8Al2=3P2Ca3 » 8AI2O3. The product is a 
brown mass, which, when left in the air, decomposes, 
giving phosphoretted hydrogen and a powder consisting of 
a mixture of alumina and the phosphide. By the action of 
Water on calcium phosphide phosphoretted hydrogen is 
readily and rapidly obtained, the only impurity being 
traces of hydrogen. 

Action of Sulphur Chloride on Metallic Oxides. — 
F. B iurion. — Sulphur chloride readily converts into 
chlorides even those metallic oxides with which a mixture 
of chlorine and sulphur dichloride gives poor results. The 
equation is 2MO +282012 = SO2 + 2MCI2 f 3S, which shows 
that there is an excess of sulphur equal to three-quarters 
of that contained in the reacting sulphur chloride. Thus 
the lowest temperature at which the reaction occurs is 
determined by observing when a deposit of sulphur appears, 
and the reaction is commenced at this temperature ; the 
temperature is afterwards gradually raised to a red heat. 
With MnOz, MnO, NiO, CoO, and the oxides of the rare 
earth the action begins before the boiling point of sulphur 
is reached, and with chromium sesquioxide at a tempera- 
ture above the boiling-point. 

Colour Reactions of Dioxyacetone. — G. Deniges. — 
In sulphuric acid dioxyacetone condenses with mono or 
polyphenolic compounds and certain alkaloids, giving 
stable colorations. These reactions are very sensitive. 
With codein a blue colour is obtained, with resorcin at the 
ordinary temperature a tint resembling that of alkaline 
dichroinates, with thymol blood-red, and with .^naphthol 
at the temperature of the water-bath a green coloration 
and a fluorescence of the same shade. The reactions with 
thymol and resorcin are particularly delicate. 

Nature of Hofmann's Brominated Acetatnide. — 
Maurice Fran9ois. — The substance which Hofmann called 
brominated hydrated acetamide, and to which he attributed 
the formula CH3 — CO— NHBr.H20, really contains all its 
bromine in the form of hypobromite. It can be prepared 
by evaporating a mixture of hypobromous acid and acet- 



amide, and when obtained thus preserves all its cha- 
racteristic properties. It must therefore be regarded as 
acetamide hypobromite, and its formula must be written 
CH3— CO— NHz.BrOH. Moreover, the substance Hof- 
mann prepared by removing water from the preceding 
compound at 50°, and which he called brominated acet- 
amide, must be a hypobromous amide, CH3 — CO — NHBr ; 
it is thus a secondary amide of acetic and hypobromic 
acids. 

Products of Saponification of Dioxalsuccinic Ether. 
Isopyromucic Acid. — E. E. Blaise and H. Gault. — The 
authors prepared dioxalsuccinic ether by the action of two 
molecules of oxalic ether upon one molecule of succinic 
ether in presence of sodium ethylate, and saponified it 
with concentrated hydrochloric acid at the ordinary tem- 
perature. The product which is obtained by evaporating 
the aqueous solution has the formula C6H4O5, and from 
this by the elimination of CO2 isopyromucic acid is ob- 
tained. Apparently hydrochloric acid lactonises the ether 
as well as saponifying it, and the product of the action is a 
^-lactone. 

Preparation of Aldehydes and Anhydrides of 
Acids. — A. Behal. — Acetic acid reacts with benzyl 
chloride giving benzyl acetate and hydrochloric acid. In 
presence of the chlorides of zinc, antimony, or copper one 
molecule of C6H5 — CHCI2 reacts with one molecule of 
acetic acid, giving benzoic aldehyde, acetyl chloride, and 
hydrochloric acid — 
CgHc— CHCl2-f-CH3C02H = 

= C6H5— CHO f CH3— COCl -I- HCl. 
Large quantities of polymerisation products of benzoic 
aldehyde are also formed. 



MEETINGS FOR THE WEEK. 



Monday, March ist.— Royal Society of Arts, 8. (Cantor Lecture). 
" Modern Methods of Artificial Illumination," 
by Leon Gaster. 
— — Royal Institution, 5. General Monthly Meeting. 

^— Society of Chemical Industry, 8. " Soma Re- 

quirements of a Colour Standard," by J. W. 
Lovibond, " Sulphur as a Cause of Corrosion 
in Steel," by G. N. Huntly. 
Tuesday, 2nd.— Royal Institution, 3. "Evolution of the Brain as 

an Organ of Mind," by Prof. F. W. Mott, F.R.S. 

Wednesday, 3rd.— Society of Public Analysts, 8. "Composition of 

Cider," by B. T. P. Barker and E. Russell. 

" Composition and Analysis of Chocolate," by 

N. P. Booth, C. H. Cribb, and P. A. E. 

Richards. " Determination of Petroleum in 

Turpentine," by J. H. Coste. 

Thursday, 4th.— Roval Institution, 3. "Problems of Geographical 

Distribution in Mexico," by Hans Gadow, F.R.S. 

Chemical, 8.30. " Action of Anhydrosulphuric Acid 

on Triphenylsilicol," by G. Martin and F. S. 
Kipping. "Ignition Temperatures of Gases," by 
H. B. Dixon and H. F. Coward. " Diazo-oxy- 
amido Compounds and the Influence of Sub- 
stituting Groups on the Stability of their 
Molecules," by N. L. Gebhard and H. B. 
Thompson. "Tetraketopiperazine," by A. T. de 
Moulpied and A. Rule. " Alkaloids of Senecio 
latifolius," by: H. E. Watt. "Miscibility of the 
Pyridene bases with Water and the Influence of a 
Critical Solution-point on the Shape of the Melting- 
point Curve," by O. Flaschner. " An Interpre- 
tation of the Hantzsch-Werner Hypothesis," by 
M. O. Forster and P. F. Dunn. "The Triazo- 
group -Part IX., Transformation of Cinnamoyl- 
azoimide intoCinnamenylcarbimide (Cinnamenyl- 
isocyanate), by M. O. Forster. " Preparation 
of Dichlorocarbamide," by F. D. Chattaway. 
" Interaction of Methylenediamines or Methyletie- 
anilinesand Carbimides orThiocarbimides — Thio- 
tetrahydroquinazolines Methylene Ureas. Dicarb- 
anilidomethylene Diamines and their Homo- 
logues," by A. Senier and F. G. Shepheard. 
Friday, sth.— Royal Institution, g. " Letters of Queen Victoria," by 
the Rt. Hon. Viscount Esher, G C.B., &c. (By the 
gracious permission of His Majesty the King). 
Saturday, 6th.— Royal Institution, 3. " Properties of Matter," by 
Prof. Sir J. J. Thomson, F.R.S. 



Chehical'Nbws, 

March s, 1909 



Tetravalency of Oxygen. 



tog 



THE CHEMICAL NEWS 



Vol XCIX., No. 2571. 



HON THE TETRAVALENCY OF OXYGEN. 

By H. STANLEY REDGROVE, B.Sc. (Lond.), F.C.S. 

In the Proceedings of the Chemical Society, No. 350 
(vol. XXV., p. 16) a " Note on the Constitution of the 
Carboxyl Group " appears by Miss Smedley, in which 

"the constitution -Cf || is suggested for the carboxyl 

\0H 
group as better representing its physical and chemical 
behaviour." Some time ago, in connection with an exami- 
nation of the thermal behaviour of organic oxygen com- 
pounds, a similar view of the carboxyl group suggested 
itself to the author of the present paper. It was noticed 
that an accumulation of oxygen atoms in a molecule is 
accompanied in certain cases by a lower molecular heat of 
combustion than would be expected from theory. For 
example, consider the successive substitution by the 
melhoxyl group of the hydrogen atoms in methane ; as 
will be seen from Table I., each successive methoxyl 
group produces a smaller increment in the molecular 
heat of combustion than the preceding. It was thought 
that the extra stability of these compounds containing 
two or more oxygen atoms might be explained by 
the hypothesis of tetravalent oxygen ; for, if it be granted 
that oxygen can function as a tetravalent element (and for 
this there is a considerable amount of experimental evi- 
dence), there seems to be no good a priori reason against 
concluding that in compounds containing two or more 
oxygen atoms situated sufficiently near one another the 
secondary oxygen valencies are operative between such 
oxygen atoms, and consequently, that when such sub- 
stances are burned, a certain amount of energy obtained 
otherwise as heat is employed in severing such oxygen 
links. According to this view methylal would be repre- 

/OCH3 
sented by the constitutional formula CH2<f II , methyl 

\0CH3 
orthoformate by — 




the carboxylic acids by the general formula suggested by 
Miss Smedley, the esters of such acids by the general 

/° 
formula R.C< jl , &c. 

\0.R 

However, in attempting to consistently carry out this 

hypothesis, difficulties were raised equal to those which 

were obviated by it ; and after careful consideration it was 

concluded that the hypothesis could not be justified by the 

thermal data under consideration. In view, however, of 

Miss Smedley's Note it will not be without interest to give 

a brief account of those considerations which suggested 

the above hypothesis and the difficulties which it raised, 

in the hope that some explanation of the anomalies herein 

noticed may be forthcoming. 

Arguments for the Hypothesis. 

I. In the examination of the thermal behaviour of 
ketonic oxygen three values were obtained for the constant 



Table I. 

Substance. Formula. 

Methane CH4 

Dimethyl ether . . . . CH3.OCH3 

Methylal CH2(OCH3)2 

Methyl orthoformate . CH(OCH3)3 

Table II. 
Carbon dioxide. . .. CO2 
Carbonyl chloride . . COCI2 
Carbon tetrachloride . CCI4 



M.H.C. (a) Difference. 
Cals. Cats. 



aio-S 

348-2 

598-0 } "3-1 



137-4 
126-7 



Carbon dioxide . . 
Carbonyl sulphide 
Carbon disulphide 



Table III. 

CO2 
COS 

CS2 



o-o 
42-1 
76-5 



130-7 
264-5 



42-1 

34-4 



130-7 

133-8 



(a) Ail the experimental molecular heats of combustion 
given in this paper are due to Thomsen, and have 
been corrected for constant volume. It should be 
borne in mind that, since this data relates to gaseous 
compounds, the arguments which follow will hold, 
strictly speaking, only in the case of gaseous sub- 
stances. In the liquid state many organic oxygen 
compounds appear to be associated, and this asso- 
ciation may probably be due to tetravalent oxygen ; 
if this be so, then, since the secondary oxygen links 
are employed in binding together smaller molecules 
into more complex ones, it is obvious that they 
jOigg cannot at the same time (or at least, that both 
secondary links cannot) be operative within the 
smaller molecules of such substances. 



a>2* — for aldehydes 4^2=87-7 cals., for ketones W2 = 9i'4 
cals., for carbon dioxide, mono-basic carboxylic acids and 
their esters W2 = 105-4 cals. This apparently anomalous 
behaviour was explained in terms of the theory of dynamic 
isomerism ; and there can be little, if any, doubt that the 
presence of the enolic form is one factor producing an 
abnormally high molecular heat of combustion in the cases 
of aldehydes and ketones. However, it might well be 
supposed, since the value W2 - 105-4 cals. has been obtained 
only in the cases of compounds containing two oxygen 
atoms, that the highness of this value (and hence the 
lowness of the molecular heats of combustion calculated 
thereby) may be due in part to the presence of tetravalent 
oxygen in such compounds. This suggestion is strengthened 
by the following consideration. 

2. Carbonyl chloride is represented by the formula 
COCI2, i-e., 0-2X-W2, its molecular heat of combustion 
is 42-1 cals., which gives still another value for 012, namely, 
97-7 cals. Now, carbonyl chloride cannot be subject to 
dynamic isomerism and, since the affinity of oxygen for 
chlorine is small, we should not suppose that there is 
operative any secondary link between the oxygen and 
chlorine atoms contained in its molecule. Hence, it might 
be concluded that this value (97*7 cals.) is the true value 
of 0/2 ; the difference between it and the higher value 
being the thermal equivalent of an 0:0 link ; and the 
divergence in the cases of aldehydes and ketones being 
due to the presence of the enolic form which theoretically 
would have a relatively high molecular heat of combustion. 

This argument can be otherwise presented by a com- 
parison of the thermal behaviour of carbon dioxide, 
carbonyl chloride, and carbon tetrachloride (see Table II.). 
It will be seen that the substitution by oxygen of the 
first two chlorine atoms in carbon tetrachloride produces 
a less decrease in the molecular beat of combustion than 



* For the meaning of this and other constants mentioned in this 
paper, and for an explanation of the author's method of calculating 
thermochemical constants, reference may be made to back numbers 
of the Chemical News, but a full and complete account will be found 
in the author's monograph " On the Calculation of Thermo-Chemical 
Constants" (Arnold). 



no 



Chemically Treated Flours. 











( Chemical Nbw s 










1 1 


March 5, 1909 


M.H.C. 


calculated 




Difference. 




Cal! 


. 




Cals. 


617-0 










+ 19-0 


376-2 
3«3-9 


((i>2 


= 


105-4 


cals.) 


+ 19-2 


(W2 


= 


977 


cals.) 


+ 26-9 


692-8 (W2 


= 


105-4 


cals.) 


+ 199 


700-5 


(a>2 


= 


977 


cals.) 


+ 27-6 


1 452-0 


(W2 


= 


105-4 


cals.) 


-7*5 


\ 467-4 


(W2 


= 


977 


cals.) 


+7-9 







Table IV 




Substance. 


Formula. 


M.H.C. found 
Cals 


Methylorthoformate 


CH(OCH3)3 


40 -3w 


598-0 


Dimethyl carbonate 


0:C(OCH3)2 


3a — 2W-W2 


357*o 


Diethyl carbonate.. 


0:C(OC2H5)2 


5a-23— 2w— wa 


672-9 


Acetic anhydride . . 


(CH3CO)20 


4a - 2/3 - <o - 2W2 


459'5 



the similar substitution of the last two, which appears to 
be explicable if we assume the existence of an O : O link 
in the carbon dioxide molecule. (We take for granted 
that no secondary chlorine links are operative in the 
carbon tetrachloride molecule). An examination of the 
corresponding compounds containing sulphur in place of 
chlorine shows a regular behaviour (see Table III.). But if 
we regard oxygen as exerting a tetravalent function in 
carbon dioxide, then, a priori, we should regard sulphur 
as tetravalent in carbonyl sulphide and carbon disulphide ; 
and since the thermal effect of these secondary links is in 
any case small, the differences between an O : O and 
an O : S link, and between an O : S and an S : S link 
respectively would be practically equal, and would not 
cause the molecular heat of combustion of carbonyl sul- 
phide to diverge more greatly from the mean between 
the molecular heats of combustion of carbon dioxide and 
carbon disulphide than it actually does. 

3. The molecular heats of combustion of methyl ortho- 
formate and dimethyl and diethyl carbonate are con- 
siderably lower than expected by theory (see Table IV.). 

Using the constants w = 75-4 cals., (02=105-4 cals., 
these three substances give an almost constant divergence, 
which might be explained by assigning them formulae con- 
taining tetravalent oxygen ; but acetic anhydride — another 
substance containing three oxygen atoms — has a molecular 
heat of combustion greater than the theoretical ! How- 
ever, if we apply the hypothesis under consideration con- 
sistently, we must use the constant 0*2 = 97-7 cals. (see 
above), for, if this hypothesis be true, in using the higher 
value an O : O link has been allowed for. If this constant 
is employed the theoretical molecular heat of combustion 
of acetic anhydride does exceed by a small amount the 
experimental value, but the four substances in question 
give by no means consistent divergences. 

Arguments against the Hypothesis. 

1. On attempting to work out the hypothesis quan- 
titatively consistent results cannot be obtained. This 
inconsistency is particularly marked in the case of the 
values obtained for the influence of the secondary links ot 
three oxygen atoms. The carbonic esters give the values 
26-9 and 27-6 cals., methyl orthoformate 19-0 cals., and 
acetic anhydride only 7-9 cals. 

2. It must be noticed that many of the apparent 
anomalies upon which the hypothesis depends can be 
otherwise explained. The behaviour of the aldehydes 
and ketones appears to And a satisfactory interpretation in 
the theory of dynamic isomerism alone ; the divergence in 
the case of methylal is small, and the value of u calculated 
from its molecular heat of combustion differs from the 
mean less than does that obtained from the molecular heat 
of combustion of diethyl ether ; and the divergence in the 
case of acetic anhydride is small, and this substance is 
still exceptional even if the hypothesis in question be 
adopted. 

3. The most fatal objection to the hypothesis herein 
outlined, however, is as follows : — It has been tacitly 
assumed in all the arguments above that when oxygen 
becomes tetravalent the thermal value of the two primary 
valencies remains unaltered, but d priori it seems far more 
likely that the total valency-energy of the oxygen atom 
will remain unaltered, and hence, that when oxygen 
functions as a tetravalent atom, the thermal value of its 



two primary valencies will be decreased, and if this be so 
all the above arguments for the hypothesis entirely break 
down. At any rate we must not assume that the value of 
the two primary oxygen valencies when oxygen is tetra- 
valent is equal to the value of the two valencies of divalent 
oxygen until proof be forthcoming ; and this objection will 
hold good in the case of all physico-chemical properties 
and not merely molecular heats of combustion and 
formation. 
The Polytechnic, Regent Street, W. 



CHEMICALLY TREATED FLOURS.* 
By E. F. LADD, Food Commissioner and Chemist. 

During the past few years there has been a great deal of 
discussion with regard to the bleaching and chemically 
ageing of flours. On the one hand it has been claimed that 
the process of artificial bleaching brings about results 
similar to those of natural ageing of flour ; while, on the 
other hand, it has been contended that there is introduced 
into the flour a powerful chemical agent which brings 
about untoward changes in the flour itself, rendering it 
less nutritious, and that the flour so artificially treated 
contains an active chemical constituent which acts as a 
preservative. Believing that the information which has 
been secured, as the result of experimental work carried on 
for the past two years, is of such a nature that it should 
be given to the public, the writer has concluded to present 
the data in substantially the same form and manner as 
presented before the District Court at Fargo, North Dakota, 
in answer to the injunctional proceedings, and also as 
presented before the Honourable Secretary of Agriculture 
and the Board of Food and Drug Inspection at Washington 
on November 18 to 23, 1908. The information is there- 
fore presented in two parts, I., The Bleaching of Four; 
and II., The Effect of Bleached Flour Extracts on Rabbits. 

I. Bleaching of Flour. 
By E. F. Ladd and H. P. Bassett. 

The bleaching of flour or the effect of nitrous acid upon 
ihe different constituents of a flour is a subject which has 
been but little investigated, and is a field which promises 
to yield interesting results where the investigations are 
pushed along new lines. 

During the past few years the millers of North Dakota, 
as well as of the entire country, have been using nitrous 
acid fumes or nitrogen peroxide produced in different ways 
for bleaching or " ageing of flours." It seems that no other 
bleaching agent lends itself so readily to the use for this 
particular purpose. 

Nearly all the work done along this line has been under- 
taken to determine the effect on the gluten expansion, 
volume of loaf, blending of bleached flour with higher 
grades of flour, &c. With the exception of a paper sub- 
mitted by Prof. J. H. Shepard, Chemist of the South 
Dakota Experiment Station and Food Commission, nothing 
has been done to determine the effect of this highly 
poisonous gas, nitrogen peroxide, or of the resulting pro- 

* Special Bulletin from the Government Agricultural Experiment 
Station, Agricultural College, N.D., December, 1908. 



Chemical News, 
March 5, 1909 



Chemically Treated Flours. 



iri 



ducts on digestion. This, therefore, may be considered 
the most vital point to be considered, because it is here 
that the deleterious effects, if such there are, will be pro- 
duced upon man. On certain phases of this question con- 
siderable work has been done by Ladd and Stallings and 
by Prof. AKvay, whose results are published as Bulletin 
No. 102 of the Nebraska Experiment Station. Prof. 
Alway, however, does not seem to have investigated the 
effects upon the nitrogenous constituents or to have used 
samples of flour bleached to the extent found upon the 
market in this state, and he therefore concludes that the 
use of nitrous acid is harmless since only very small 
quantities of the reagent is used in the bleaching of flours. 
Experiments with Bleached Flour. — Our early experi- 
ments were to determine the amount of nitrous acid or 
nitrites present in samples, of bleached flour, and after a 
number of preliminary experiments with methods and 
samples of flour, a sample of the commercially bleached 
flour for trade from the Valley City Mill was found to 
contain : — 

In 5 grms . . 0*0034 mgrm. nitrogen. 

Calculated as sodium nitrite. . o"oi67i mgrm. 

In flour for one loaf of bread 

(373 grms.) i'24656 mgrms. NaNOj. 

This would be 68 parts of nitrogen as nitrite nitrogen 
per million. 

In a sample of the clear, from the same mill, as bleached 
for trade, there was found : — 

In flour for one loaf of bread 
{373 grms.) 2-4159 mgrms. NaNOa. 

This would be 13 •14 parts of nitrogen as nitrite nitrogen 
per million or 6yj parts as sodium nitrite. 

In a sample of flour taken from a Minnesota Mill there 
was found in the amount for one loaf, 373 grms., 1-313146 
milligrms. as NaNOz. 

Amount in Bread. 

A sample of bread, produced from the flour as com- 
mercially bleached from the Valley City Mill, was analysed 
to determine the amount of nitrites present, when cal- 
culated as sodium nitrite. 373 grms. produced a loaf 
weighing, approximately, 18 ounces or 509 grms., and was 
found to contain o'44352 milligrm. as NaNOa, or, approxi- 
mately, one-third of the amount originally found in the 
flour. 

A sample of bread produced in the same way from over- 
bleached flour, from the Valley City Mill, showed 3546 
milligrms. NaNOa, or, slightly less than one-third of that 
found in the flour. 

Effect of Bleaching on Fat. 
Fat extracted from the unbleached Valley City Mill 
flour that has stood in the laboratory for nine months gave 
iodine No. (Hanus Mod.) 101-2°. A sample of the same 
flour, bleached, and which had stood in the laboratory for 
nine months after bleaching, gave iodine No. (Hanus Mod.) 
84-1°. Other tests showed similar results. The oil from 
the bleached sample was more stringy and like the results 
of the action of the nitrous acid or nitric acid, or the 
combined action of the same in producing elaiden. 

Nitrogen combined with Oil. 

Two samples of flour, the one bleached and the other 
unbleached of the same, were extracted with ether. About 
200 grms. of flour were used, the ether distilled off, leaving 
the fat, and the residue taken up in re-distilled petroleum 
ether solution, carefully filtered, and the petroleum ether 
thoroughly evaporated off, thus getting rid of any impurities 
which may have been originally in the oil from ether 
extraction. 

The tests for the presence of combined nitrogen and fat 
were made as follows : — 

A piece of well cleaned metallic sodium was strongly 
Ideated iri an ignition tube, and three drop s of the wheat 



flour oil was then allowed to fall upon the partly vaporised 
sodium. When cool, the contents of the tube were firtt 
treated with a little alcohol and then with water. This 
solution was then filtered, treated with a few drops of 
sodium hydroxide solution and with ferrous sulphate solu- 
tion, then boiled for a minute or two. Just enough of 
dilute hydrochloric acid was added to dissolve the precipi- 
tate, and, finally, a drop or two of ferric chloride solution 
was added ; the presence of nitrogen being indicated by a 
precipitate of Prussian blue. 
Oil from unbleached flour No nitrogen . 
Oil from bleached flour Considerable combined nitrogen. 

Numerous other tests made upon the oil from bleached 
and unbleached flour gave similar results. 

Tests were next made upon the oil extracted from bread 
produced from bleached and unbleached flour without the 
addition of any foreign fat. The loaf was dried, ground 
to fine meal, extracted with ether, and purified with 
petroleum ether, as previously described, with results as 
follows : — 

Oil from bread, unbleached . No combined nitrogen. 

Oil from bread, bleached . . Combined nitrogen. 

The amount of nitrogen in the oil from the sample 01 
bread made from the bleached flour was less than in that 
of the flour from which the bread was produced. 

Nitrous and Nitric Acid Present. 

Tests were made showing the presence of both nitrous 
and nitric acid, or nitrites and nitrates, as reacting material 
in flour, which had been bleached by the use of nitrogen 
dioxide or tetroxide. In numerous of the experiments 
made, from one-third to one-half of the amount of nitrites 
found in the flour are recovered in the bread made by the 
usual process with yeast as a leavening agent. In the case 
of biscuit, rolls, and like products where baking powder or 
soda is used and in the thinner products, the nitrites are 
in a large measure destroyed or by oxidation changed to 
nitrates. 

The Effect of Bleaching on Digestion. — In Prof. 
Shepard's work he investigates the effect of nitrous acid 
on the action of the digestive enzymes on pure corn 
starch. This, however, leaves out the action on flour, 
bread, and other products where protein bodies, and in 
some cases starch, are present, and on this point the 
following work is reported. 

Effect of Bleaching on Digestion of Gluten and Bread, 
The pepsin solution used in these experiments was pre- 
pared according to the directions given in Simon's " Physio- 
logical Chemistry, "page 450, which is as follows : — 
The following three solutions were prepared : — 
A. — To 294 cc. of water 6 cc. of hydrochloric acid 
(i-2o sp. gr. diluted to 10) was added. 

B. To 100 cc. of solution A, o-o6 grm. of pepsin was 

dissolved. 

C. 90 cc. of solution A was brought to 40° C. in a 

digestion oven and 10 cc. of solution B was then 
added. 

These experiments were carried out in the following 
manner : — 

A test-tube | inch in diameter was cut off, forming a 
short tube about 3^ inches long; in the bottom of this a 
hole was blown to allow the digestion solution to come in 
contact with the substance to be digested. In the bottom 
of this tube was placed a plug of glass-wool, packed with 
a glass rod, and on this plug was placed the gluten or 
bread to be digested. This was then immersed in the 
flask containing the digestion solution, and the time noted 
until the bread or gluten had disappeared. The time 
could not be accurately determined, but when there was a 
marked difference, as is shown in some cases, a relative 
figure can be determined. 

Eight trials were made in the manner described, using 
the raw gluten obtained by washing out 10 grms. of com- 



112 



Apparatus for Decanting and Filtering, 



Chemical News, 
' March 5, 1909 



mercially bleached flour by the usual method and treating 
with 200 cc. of solution C. The following results were 
obtained : — 

Gluten from Bleached Flour. 



, of Tube. Time of Digestion. 

1. 8 hours. 

2. 8J hours. 

3. 9 hours. 

4. Left over night and the oven cooled down. 

5. Started 7.30 a.m., and allowed to run until 

6.0 p.m., and hardly could be said to be fully 


6. 

7- 
8. 


g hours. 
10 hours. 
8 hours. 



ime of digestion 


Hrs. 


Mins. 


4 





4 


30 


4 





4 





5 





4 


30 


5 


30 


6 





6 





6 






Ten trials were made under the same conditions as in 
the case above, using the gluten from 10 grms. of un- 
bleached flour with the following results : — 

Gluten from Unbleached Flour. 

No. of tube. 
I. 
2. 

3- 
4- 
5- 
6. 

7- 
8. 

9- 
10. 

In the above cases raw gluten was used, and raw material 
of this character is much harder to digest than when 
cooked in some form, so it was thought advisable to try 
the action of the digestion fluids on baked gluten. 

The baked gluten from 10 grms. of flour was treated 
in the manner previously described, but no such marked 
difference could be detected as the digestion was much 
more rapid and the difference in time could not be noted 
as well. 

Baked gluten from bleached flour was first tried with 
the following results : — 

Time of digestion. 
No. of tube. Hrs. Mins. 

1. 30 

2. 3 30 
3- 2 30 
4. 2 30 

5- 3 30 

6. 3 30 

It will be noted that two of the above trials required 
only two and a-half hours, but in most cases over three 
hours were required. 

Baked gluten from unbleached flour was next tried in 
the same manner with the following results : — 





Time of digestion 


)o. of tube. 


Hrs. 


Mins. 


I. 


2 





2. 


I 


45 


3- 


2 





4- 


2 


30 


5- 


2 






In only one case did the baked gluten from unbleached 
flour require over two hours. 

The nexftrials along this line were carried out on bread 
made from each of the flours. The following table will 
give the results obtained with bread made from bleached 
flour : — 

No. of tube. Time of digestion. 

Hrs. Mins. 

1. 20 

2. 1 45 

3. 3 o 



The results with the bread made from the unbleached 
flour are given below : — 



No. of tube. 
I. 
2. 

3- 



Time of digestien. 

Hrs. Min. 



30 
45 



It will be noted that the time of digestion was in favour 
of the unbleached flour, but the times of digestion are so 
close that the results are not necessarily as definite as in 
the case of raw gluten. 

(To be continued). 



AN APPARATUS FOR DECANTING 

AND FILTERING. 

By J. HUDIG. 

When decanting or filtering by hand considerable diffi- 
culties are often encountered, whilst by the constant 
moving of the vessel holding the liquid and the precipitate, 
the latter is stirred up so that small quantities of the pre- 
cipitate pass over into the filter, and thus partially clog the 
same. If easily movable or colloidal precipitates are to be 
dealt with, it will occasion a considerable delay in the 
filtration. 

As keeping the filter constantly filled is an absolute 
necessity for rapid filtration, it is difficult to effect several 
filtrations simultaneously, especially when the liquid to be 
filtered is at a high temperature. 

I, however, succeeded in constiucting an apparatus by 
which several filtrations can be effected simultaneously. 
The apparatus I have used for two years is shown by 
Fig. I. 

On a shaft, which is rigidly fixed to a stand, several 
holders are rotatively arranged by means of sockets. The 
holders consist of a wooden block. The flask upon the 
block is held by an adjustable spring, which is prolonged 
upwardly and provided with a pivoted perforated tension 
plate. The wooden block is provided with a clamping 
spring for the purpose of attaching a glass rod for forming 
drops and guiding the liquid. The neck of the flask is held 
close to the glass rod. 

At the side of the socket a wooden wheel is fitted, which 
engages with a screw spindle movably arranged in a guide ; 
this guiding piece is rigidly fitted to the shaft. The free 
ends of the screw spindle are displaceable longitudinally in 
the guiding piece, and for the purpose of maintaining the 
same in any desired position a clamping nut is provided. 
The screw spindle is thus free to turn, whilst a longitudinal 
displacement of the same is prevented by the fixing of the 
stop screw. The manipulation is as follows : — The flask 
with the fluid is put on the block, and then the clamping 
ring is closed by means of the plate, thus firmly holding 
the flask, which has an inclined position. After some time 
the precipitate settles to the bottom of the flask. Now the 
clamping nut is unscrewed so that the screw spindle can be 
pushed down, which puts the wheel in rotation, and so the 
flask is raised until the liquid nearly flows out of the 
mouth, after which the clamping nut is fastened again. 
Now, a glass rod is held to the neck of the flask by means 
of the spring. Then the spindle is slowly rotated by 
means of its button in order to pour out the liquid which 
is to be filtered. The supply of the liquid can be exactly 
regulated so that the liquid flows for some time, and the 
filter remains constantly filled. Nothing of the precipitate 
is stirred up. 

Finally, the flask can be lifted so high that all the liquid 
has been poured out and the precipitate has been completely 
freed from liquid. For the purpose of washing, the flask is 
turned back and the washing fluid sprayed in. Now, in 
order to shake the flask, the clamping nut is released, and 
the spindle is moved to and fro. Then the filtering is con 



CHEMtcAL News, 
March 5, 1909 



Apparatus for Decanting and Filtering. \ 



113 




Fig. 3, 




Fig. 2. 




Fig. 3. 

ttnued as described above, and finally the precipitate can 
be sprayed together with the washing liquid into the filter. 
It is easy to perceive that with this apparatus the fol- 
lowing advantages can be obtained : — 

1. The fluid is decanted absolutely free from precipitate. 

2. The filter is constantly filled. 

3. The precipitate can be completely freed rom liquid. 

4. Several filtrations can be simultaneously effected. 

5. Working in this way the manipulation of decanting is 

much more convenient and also less tedious than 
ordinary filtering by hand. 



Some of my experiments may be illustrated. 

Determining P2O5 in Thomas Slag. — For instance, when 
the acid solution of ammonium molybdate is added, 
and the mixture boiled in order to precipitate the 
(NH4)3P04.i2Mo03 well, I put six flasks upon the blocks, 
and fasten them (each flask contains J: 160 cc), filter, 
wash, and bring the precipitate upon the filter within 
twenty minutes. 

Then the flasks are loosened, the solution of the yellow 
precipitates in NH3 filtered into them, neutralised, and the 
phosphoric acid is precipitated by magnesia mixture. The 
flasks are again put into the apparatus and treated as 
before. All can be done in a quarter of an hour. 

Specially I have had experience with colloidals, as 
Fe(0H3), A1(0H)3, MnOa, Mn(0H)2, and several sulphides. 
Formerly I took for one filtration of MnO (which may not 
come into contact with the air) in 400 cc. liquid about two 
hours ; now I easily effect three of them simultaneously 
in about half-an-hour. 

When operating with beakers springs of the same shape 
as shown in Fig. i can be used, only they must be some- 
what bigger. Fig. 2 shows these springs in detail. One 
spring can be used for several sizes of beakers. 

I now use when operating with Erlenmeyer flasks a 
spring as is shown by Fig. 3. A caoutchouc ring must be 
put round the neck of the flask and then placed upon the 
block, so that the ring is put just before or within the 
spring. 

At the experiment station of Groningen, where often 
several analyses are to be done simultaneously, two 
apparatus for six filtrations have been of great advantage. 

Different apparatus for six, four, and two filtrations are 
now constructed by Mr. Marius, of Utrecht (Holland). 
Shortly this apparatus, which has been licensed in England, 
will be also manufactured by an English firm. 



Royal Institution. — A General Monthly Meeting of 
the Members of the Royal Institution was held on the 
1st instant. Sir James Crichton-Browne, M.D., F.R.S., 
Treasurer and Vice-President, in the Chair. The Right 
Hon. Sir George Wyatt Truscott, Lord Mayor, Mr. A. E. 
Garrett, Mr. D. Jones, Mr. E. Lunge, Dr. J. H. Openshaw, 
and Miss Power were elected Members. The special 
thanks of the Members were returned to Mrs. Wigan for 
her donation of ten guineas to the Fund for the Promotion 
of Experimental Research at Low Temperatures. The 
Honorary Secretary reported the death of Prof. Julius 
Thomsen, the distinguished Danish chemist, and an 
Honorary Member of the Institution, and a resolution of 
condolence with the family was passed. 



114 



Decomposition and Sublimation of Ammonium Nitrite. 



( Chemical News, 
1 March 5, 1909 



PROCEEDINGS OF SOCIETIES. 

CHEMICAL SOCIETY. 
Ordinary Meeting, February lith, 1909. 

Sir William Ramsay, K.C.B., F.R.S., President, in the 
Chair. 

The President referred to the loss sustained by the 
Society in consequence of the death of three Honorary 
and foreign Members, Professor Wolcott Gibbs (elected 
May 3rd, 1866 ; deceased, December gth, 1908), Professor 
Emil Erlenmeyer (elected February ist, 1883 ; deceased, 
January 22nd, 1909), and Professor Julius Thomsen, F.R.S. 
(elected May i8th, 1876; deceased February 13th, 1909)- 
The death of Professor W. H. Huddleston, F.R.S , was 
also announced. 

The President stated that the Council had recom- 
mended Professor Dr. Georg Lunge as an Honorary 
and Foreign Member, and that his election would lie 
balloted for at the next Ordinary Scientific Meeting of the 
Society. Fellows wishing to participate in the forthcoming 
Celebration of Professor Lunga's seventieth birthday on 
September 15th, 1909, should forward their subscriptions 
to Professor E. Bosshard, EidgenossischesChemiegebaude, 
Ziarich. 

Messrs. D. Avery, W. C. Birch, H. Green, and H. 
Main were formally admitted Fellows of the Society. 

Certificates were read for the first time in favour of 
Messrs. Hugh Garner Bennett, M.Sc, 13, Spring Grove 
Terrace, Leeds; Frank Playfair Burt, B.Sc, Elmhyrst, 
Weston-super-Mare ; Reginald Cyril Herbert Cooke, 17, 
St. Edmund's Teirace, Regent's Park, N.W. ; Henry 
Jermain Maude Creighton, M.A., Halifax, Nova Scotia, 
Canada ; Philip Henry Crewe, Glencairn, Woods Moor, 
Stockport ; John Frederick Haws, Parkfield Villa, Newton- 
by-Frankby. Cheshire ; Reginald Vernon Hickinbotham, 
144, West Street, Maritzburg, Natal; Arthur Edwin Tate, 
B.Sc, Gladstone House, Salter Row, Pontcfract ; Francis 
Lawry Usher, B.Sc, 18, Clifton Park, Bristol. 

The selection by the Council of Professor F. S. Kipping, 
F.R.S., as Longstaff Medallist for 1909 was announced, 
the presentation to be made at the Annual General 
Meeting. 

It was stated that the following changes in the Officers 
and Council were proposed by the Council : — 
President to retire— ?)\r William Ramsay, K.C.B. 
Vice-Presidents to retire— Di. R. Messel and Prof. 
W. H. Perkin. 

Ordinary Members oj Council to retire — Dr. H. A. D. 
Jowett, Dr. F. E. Matthews, Dr. W. J. Sell, Dr. J. Wade. 
As President— Ptof. Harold B. Dixon. 
As Vice-Presidents who have filled the office of President 
—Prof. H. E. Armstrong, Prof. A. Crum Brown, Sir 
William Crookes, Sir James Dewar, Dr. A. G. Vernon 
Harcourt, Prof. R. Meldola, Dr. H. Miiller, Prof. W. 
Odling, Sir William Ramsay, Prof. J. Emerson Reynolds, 
Sir Henry E. Roscoe, Dr. W. J. Russell, Prof. T. E. 
Thorpe, and Prof. W. A. Tilden. 
As Treasurer — Dr. Alexander Scott. 
As Hon. Secretaries— Dt. M. O. Forster and Prof. 
Arthur W. Crossley. 

As Foreign Secretary— Dt. Horace T. Brown. 
As Vice-Presidents— Fiot J. Campbell Brown, Prof. 
J.N. Collie, Dr. J. J. Dobbie, Prof. F. S. Kipping, Sir A. 
Pedler, Prof. James Walker. 

As New Ordinary Members of Council — Prof. W. A. 
Bone, Mr. C. E. Groves, Dr. G. T. Morgan, Dr. A. E. H. 
Tutton. ■ , , 

Dr. Arthur Harden, Dr. V. H. Veley, and Dr. J. A. 
Voelcker were elected Auditors to Audit the Society's 
Accounts. 

A ballot for the election of Fellows was held, and the 
following were subsequently declared elected : — 



George Henry Joseph Adlam, B.A. ; Hubert Brunskill ; 
Arthur Clayton, B.Sc ; Herbert Edwin Cocksedge, B.A., 
B.Sc ; Alfred Bertram Coles, M.A. ; John Charles Jesser 
Coope; Frederick Percy Dunn, B.Sc; Frederick Ferra- 
boschi ; John Thomas Fox ; Arthur Gordon Francis, 
B.Sc. ; John Thomas Furnell ; Ross Aiken Gortner, M.A., 
B.Sc ; John Wilberforce Green ; Alfred George Cooper 
Gwyer, B.Sc, Ph.D.; Robert Main Harland ; Walter 
Norman Haworth, M.Sc. ; Eric Hayward ; Frank Higson ; 
James Henry Hoseason ; Ralph Hough ; Robert Ernest 
Jackson ; John Hugh Jeffery ; Henry Humphreys Jones ; 
Horace Keeble ; Joseph Leedham ; John Esson McGillvray, 
M.A. ; William George Martin, B.Sc. ; Percy May ; William 
Norton Morley, B.Sc. ; Frederick Hubert Painter, B.Sc. ; 
Joseph Allen Pickard, B.Sc ; Frank George Pope ; Colston 
James Regan ; Robert Robinson, M.Sc. ; Herbert Rogers ; 
Philip John Sageman ; J. H. Charles Schulten, Ph.D.; 
David Segaller ; James Thomas Stevenson ; Reginald 
Wells Varley ; Guy Ransom Warwick, B.A. ; Percy 
Charles Henry West ; Thomas Jabez Wild. 

Of the following papers, those marked * were read : — 

'45. "A Study of some Asvmmetric Compounds." By 
Frederic Stanley Kipping. 

When a rf/-acid is treated with a d-base, the product is 
a mixture of the dAdB- and /AdB-salts, and when a d-ac'id 
is combined with a <^^base, the components of the product 
are dAdB and dAlB. If therefore A and B represent a 
particular acid and a particular base respectively, and dl-A 
may be resolved with the aid of d-B, it might be inferred 
that dl-B could also be resolved with the aid of d-A. The- 
dAdB-component is common to both original products, 
and as lAdB and dAlB are enantiomorphously related and 
have the same solubility in any given optically inactive 
solvent, the observed difference in solubility between 
dAdB and lAdB should also be effective in the case of 
dAdB and dAlB. 

Now d/-sulphobenzylethylpropylsilicyl oxide may be re- 
solved with d- (or with /-) methylhydrindamine {Trans., 
1908, xciii., 457) ; experiments showed, however, that 
rf/- methylhydrindamine could not be resolved with the aid 
of d-sulphobenzylethylpropylsilicyl oxide under similar 
conditions. 

dZ-Methylhydrindamine may be resolved by fractionally 
crystallising its rf-hydrogen tartrate from water (Tattersall, 
Trans., 1904, Ixxxv., 169) ; it is now shown that ^/-tartaric 
acid may be resolved with d-methylhydrindamine under 
similar conditions, and that both the dAdB- and the lAdB- 
components may be isolated in one series of crystallisations. 

dZ-Hydrindamine cannot be resolved by fractionally 
crystallising its d-mandelate from water ; <f/-mandelic acid, 
however, is very easily resolved by fractionally crystal- 
lising from water its salt with d- (or with / ) hydrindamine. 

These results seem to show that partly racemic molecules 
exist in solution. 

Discussion. 

Mr. A. E. Dunstan agreed with Prof. Kipping that the 
physico-chemical evidence for the existence of racemic 
compounds in solution was slight, owing to the dissocia- 
tion of these substances, but he pointed out that the 
results published by Clerk Ranken and Tayler, Stewart, 
Dunstan, and Thole, all indicated that undoubtedly there 
was a small difference between the physical properties of 
the racemic and the active compound when dissolved. 
Moreover, these differences were consistent and increased 
with the concentration. 

*46. " The Decomposition and Sublimation of Ammonium' 
Nitrite." By Prafulla Chandra Ray. 

When an aqueous solution of ammonium nitrite is heated 
in a vacuum at about 37 — 40°, only a very small portion 
of the salt decomposes according to the equation — 
NH4N02 = 2H20-J-N2; the main bulk of the salt crystal- 
lising out. If the temperature is then gradually raised to 
70°, slow decomposition continually proceeds according to 
the above equation, but the major portion sublimes un- 



Chkmical News, 
March 5, 1909 



Chlorine Generated by Potassium Permanganate, 



II 



changed. When this sublimate is heated by means of a 
naked flame, the gaseous products are nitrogen and nitric 
oxide, the latter often amounting to as much as 6 per cent. 

'I;..,. . . . Discussion. 

pir. Divers remarked on the interest attached to the 
crystallisation of ammonium nitrite from its aqueous solu- 
tion and of the sublimation of a salt hitherto supposed to 
be too unstable for these operations to be possible. The 
generation of much nitric oxide when the sublimed salt 
was vaporised and further heated seemed to indicate the 
occurrence of a decomjDosition tending to that production 
of hydrazine which Professor Ray had looked for : 
2NH4N02 = N2H4 + 2H20 f 2NO, the elements of the 
hydrazine appearing as ammonia and nitrogen. 

Dr. Veley concurred with the author that ammonium 
nitrite in solution is best prepared by the decomposition of 
silver nitrite and ammonium chloride. It was a most 
interesting point that such a solution could be evaporated 
in a vacuum without decomposition, and that the am- 
monium nitrite could not only be crystallised out, but 
even purified by sublimation. 

The observation was remarkable that if the conditions 
were such that the solid salt decomposed, then nitric oxide 
in a small proportion was formed in addition to nitrogen. 
Blanchard (Zeit. Phys. Chem., 1902, xli., 681 ; and Ibid., 
1905, li., 117) had shown that when an aqueous solution 
containing potential ammonium nitrite is heated under 
atmospheric pressure, nitric oxide is formed in about the 
same proportion as that found by the author, but on re- 
duction of pressure the proportion is reduced to nil. It 
would thus appear that the solid salt and aqueous solutions 
give the same result, although under reverse conditions. 

*47. '• The Estimation oj Hydroxyl Derivatives in Mix- 
tures of Organic Compounds." By Harold Hibbert. 

Hibbert and Sudborough's method (Trans., 1904, Ixxxv., 
933) for the estimation of hydroxyl groups in carbon com- 
pounds can be applied with equal success to mixtures of 
hydroxyl derivatives with other organic compounds, for 
example, ketones, esters, nitriles, &c. It is necessary to 
take rather mare of the Grignard reagent than is sufficient 
to combine with both substances. 

In this way the author has been able to estimate 
a-naphthol in presence of various ketones, ethyl benzoaie, 
methyl hydrogen succinate, and acetonitrile, as well as 
chloral in a mixture of this with acetone. 

*48. " A Simple Method for Determining the Chemical 
Affinity of Organic Substances." By Harold Hibbert. 

Note. — The author suggests using the term affinergy 
(compounded from a^n-ity and en-^r^^' ; German equiva- 
lent = affinergie) as a substitute for Michael's chemical 
potential (Annalen, 1908, ccclxiii., 21) in order to avoid 
confusion with the physical conception of potential (as in 
electrical potential), with which it has nothing in common. 

The author has shown (preceding paper) that hydroxyl 
dierivatives can be estimated in presence of ketones if 
excess of the Grignard reagent is employed. If now a 
quantity of the latter is taken, insufficient to combine with 
both, it is obvious that a partition of the reagent between 
the two substances will take place, and the amount of 
methane evolved will depend on their relative masses and 
reaction velocities, assuming, of course, that all the pro- 
ducts (apart from the methane) remain in solution. The 
latter condition is fulfilled by working in phenetole solu- 
tion. By taking the same hydroxyl compound, mixing it 
with equimolecular quantities of various ketones, and 
using the same (insufficient) amount of magnesium methyl 
iodide solution, it is thus possible to measure the relative 
reaction velocities of the ketones towards the reagent, 
since these are indirectly proportional to the amounts of 
methane evolved. The method serves in this way as a 
means for determining the chemical affinity of organic 
compounds. 

The relative affinities (using a-napbthol) of the following 



ketones have already been determined : — Dimethyl, methyl 
ethyl, and diethyl ketone; aceto- and benzo-phenone. 

Discussion. 

Dr. Lapworth asked if the author had fully considered 
his assumption that velocity of the reaction in non- 
reversible changes might be taken as a measure of affinity. 
Scientists were agreed that changes could only occur 
spontaneously when a diminution in potential thereby 
resulted, but at present this principle, whilst often serving 
to indicate the direction of change in a chemical system, 
was difficult to develop for irreversible changes, and the 
determination of affinity seemed hardly satisfactory except 
in such cases where equilibrium conditions could be 
ascertained. 

Dr. Senter said that in his opinion the reactivity of a 
chemical system could best be expressed, with van't Hoff, 
by means of the equation : — 

Reaction Velocity = Driving Force/Resistance. 

The driving force was the " chemical affinity," and 
depended on the free energy of the system, which could be 
calculated, in a perfectly definite way, from equilibrium 
measurements. The reaction velocity might be enormously 
affected by slight changes in the medium or by catalysts, 
neither of which could, in general, modify to any great 
extent the free energy (or the chemical affinity). The fact 
that the free energy and the reaction velocity are affected 
so differently by reagents allowed to some extent of their 
investigation separately, and therefore this method of 
regarding the matter seemed to possess distinct advantages. 
The President remarked that it is essential to dis- 
tinguish between an energy and one of the factors of an 
energy : — 

just as Heat Energy = Temperature X Entropy, 

and as Electric Energy = Electric potential x Electric 

quantity, 
so Chemical Energy = Chemical Affinity x Chemical 

quantity. 

Now as chemical quantity is proportional to electric 
quantity (as is proved by Faraday's law), it follows that 
chemical and electric affinity must also be proportional. 
Therefore, by determining electric potential, chemical 
affinity is measured. 

The word " affinergy " appears to be confusing, inasmuch 
as it combines the conception of a factor of an energy with 
the energy itself. 

*49. " Chlorine Generated by Potassium Permanganate 
its Preparation and Purity." By Edgar Wedekind and 
Samuel Judd Lewis. 

The method of preparing chlorine by dropping con- 
centrated hydrochloric acid on crystals of potassium per- 
manganate, which was suggested by Graebe {Ber., 1902, 
XXXV., 43), is stated to yield the gas free from oxides of 
chlorine, but no experimental proof of this is given by that 
author. 

The purity of the gas has now, however, been ascertained 
by the following experiments : — i. On passing the gas 
through sulphuric acid no reddish coloration is produced, 
showing the absence of chlorine peroxide. (The formation 
of chlorine monoxide is improbable, as this would be at once 
decomposed by the hydrochloric acid). 2. 2"ii grms. 
of tin were heated to dull redness in a stream of the gas ; 
the residue weighed only 0-7 mgrm. 3. The gas is com- 
pletely absorbed by mercury. 4. A definite volume of the 
gas was absorbed by a solution of 15 grms. of potassium 
iodide in water, and the iodine liberated was titrated with 
sodium thiosulphate solution, of which i68*70 cc. (mean 
of four determinations) were required, whereas in a corre 
sponding experiment with chlorine, generated from pure 
manganese dioxide and hydrochloric acid (and assumed to 
be free from oxides of chlorine, carbon dioxide, &c.), 
168*67 cc. of thiosulphate solution (rnean of six dete^r 
min^tions) were used. 



ii6 



Hydrolysis of Amygdalin by Emulsin. 



r Chemical News, 
1 March 5, 1909 



Discussion. 
Dr. Scott pointed out that, as potassium permanganate 
often contains small quantities of chlorate, chlorine 
prepared by its means is peculiarly liable to be contaminated 
with traces of chlorine oxides. The only safe test for the 
presence of these is to absorb the gas in a neutral solution 
of potassium iodide, and then decolorise it exactly by 
means of sodium thiosulphate ; if, on adding to the 
colourless solution pure dilute hydrochloric acid, no iodine 
is liberated, then the chlorine may be regarded as quite 
free from its oxides, but any iodine liberated is exactly 
equivalent to the combined oxygen, since, in neutral solu- 
tion, it goes to form iodate in accordance with the fol- 
lowing equations : — 

3Cl20+7KI = 3l2-l-KI03-f6KCl 3Cl2 = 3l2 

3Cl20-H2KI+6HCl=x6l2+3H20 + i2KCl 3(0) = 3X2 
and — 

6C102+ioKI=3l2 + 4KI03-|-6KCl 3Cl2 = 3l2 

6C102+3oKI + 24HCl = i5l2 + i2H20-|-3oKCl 602 = i2l2 

Neither of the authors' assumptions (a) that hypo- 
chlorous anhydride must be absent, because of the pre- 
sence of a large excess of hydrochloric acid, or (b) that 
chlorine peroxide could not be present, as the sulphuric 
acid by which the gas was dried did not acquire a reddish 
colour, was justified. What their experiments did prove 
was that the gas thus prepared was of the same order of 
purity as that from hydrochloric acid and manganese 
dioxide. 

50. " The Isolation of the Aromatic Sulphinic Acids." 
By John Thomas. 

The aromatic sulphinic acids are characterised, as a 
class, by forming ferric salts which are insoluble in water 
and fairly concentrated mineral acids ; this property can 
be usefully applied in the separation of these acids from 
the solutions in which they are produced. The ferric salts 
of benzenesulphinic, 0- and ^-toluenesulphinic, and a- and 
iS-naphthalenesulphinic acids have been prepared and 
characterised, and simple methods indicated for converting 
them into the corresponding sulphinic acids, sulphonyl 
chlorides, and sulphonamides. 

51. "Analytical Investigation of Zirconium Metal." 
By Edgar Wedekind and Samuel Judd Lewis. 

In view of zirconium having not yet been obtained in a 
pure condition, and of the lack of analytical data regarding 
the composition of the specimens obtained by various 
workers, the authors have worked out methods of analysis 
which make it possible to determine the proportions of the 
most common impurities. The zirconium existing in the 
free state is separated as the tetrachloride from that in 
combination with oxygen by burning the substance in pure 
chlorine ; in this way the proportion of oxygen is deter- 
mined directly. Nitrogen is estimated by a method 
similar to that of Kjeldahl ; carbon by combustion of the 
metal in oxygen at very low pressure, and subsequent 
absorption of the carbon dioxide produced. 

52. " The Action of Ethylene Dibromide on Monomethyl- 
aniline." By John Gunning Moore Dunlop and 
Humphrey Owen Jones. 

By the interaction of 2 grm. -molecules of monomethyl- 
aniline with i grm. -molecule of ethylene dibromide, di- 
phenylpiperazine (m. p. 163°) is formed by a reaction 
represented by the equation : — 
4NHMePh-|-2C2H4Br2 = 

= PhN<^2\^2''>NPh,2HBr + 2NMe2Ph,HBr. 

When 4 grm. -molecules of monomethylaniline are used 
instead of 2 in this interaction, diphenyldimethylethylene- 
diamine, NMePh-CH2-CH2-NMePh, melting at 47°, is 
produced. 

53. " Salicylidene-m-toluidine, a New Phototropic Com- 
pound ; Salicylideneamines : Salicylamides." By Alfred 
Sknjer and Frederick George Shepheard. 



In continuation of previous work on acridine synthesis, 
a series of new salicylideneamines and salicylamides have 
been prepared. Among these, salicylidene-m-toluidine has 
special interest, as it exhibits phototropy (Marckwald, 
Zeit. Physikal. Chem., 1899, xxx., 140). On crystallisa- 
tion from its solutions, the crystals are pale yellow, but 
when exposed to sunlight the colour changes quickly to 
deep orange, and this colour change is reversed, although 
more slowly, when the crystals are placed in the dark. 
This reversible reaction is due to light waves of high 
refrangibility ; it does not take place in solution, and the 
sensibility of the compound remains unimpaired after at 
least a month's time. No evidence could be obtained of 
triboluminescence or phosphorescence. Salicylidene-m- 
toluidine behaves in this respect like the anhydrous chloride 
of quinoquinoline and /3 - tetrachloro-a-ketonaphthalene 
studied by Marckwald. It is similar also to the fulgenic 
acid compounds investigated by Stobbe (Annalen, 1908, 
ccclix., i). Probably phototropy in this instance, as is 
supposed to be the case in others, depends on the existence 
of two stereo- or other isomerides formed respectively under 
the influence of short or long waves of light. 

54. " The Action of Ethyl Carbamate on Esters of 
Organic Acids and Mustard Oils." By Siegfried 
Ruhemann and John Gillies Priestley. 

Ethyl phenylpropiolate does not form an additive product 
with ethyl sodiocarbamate, but condenses with it to yield 
ethyl phenylpropiolylcarbamate, CeHjCJC-CO-NH-COzEt. 
This reaction has been applied to the preparation of acyl 
derivatives of ethyl carbamate from esters of fatty and 
fatty-aromatic acids. In this way, also, ethyl formyl- 
carbamate, CH0*NH-C02Et, has been obtained, which is 
readily hydrolysed by mineral acids, even in the cold. 

The esters of benzenecarboxylic acids form either only 
very small quantities of the acyl derivatives of ethyl 
carbamate as with ethyl benzoate, or no trace of the acyl 
carbamate, as with ethyl o-phthalate. 

Phenylthiocarbimide reacts with ethyl sodiocarb- 
amate to form carboxyethylphenylthiocarbimide, 
NH(C02Et)-CS-NH-C6H5 (see Doran, Trans., 1896, Ixix., 
326), and a yellow compound having the formula 
CeHj-NH-CS-N— CO 

I I , which is anhydro-diphenyldithio- 
C6H5-N:C— S 
biuretcarboxylic acid. It forms colourless sodium and 
potassium salts, and is readily decomposed by alkalis. 
Allylthiocarbimide yields with ethyl sodiocarbamate a sub- 
stance, CgHiiON3S2, with similar properties to those of 
the former compound. 

55. " The Hydrolysis of Amygdalin by Emulsin. 
Part III. Synthesis of A-Benzaldehy decy anohy drin." By 
Samuel James Manson Auld. 

The assumption generally made that benzaldehyde- 
cyanohydrin must be formed as an intermediate product of 
the decomposition of amygdalin by emulsin is objected to, 
and evidence has been brought forward showing than an 
asymmetric synthesis of rf-benzaldehydecyanohydrin takes 
place under the influence of emulsin, and that its formation 
in this manner proceeds more rapidly than its formation 
during the hydrolysis of amygdalin by emulsin. Emulsin 
can also induce the formation of an optically active 
hydroxybenzaldehydecyanohydrin from hydroxybenzalde- 
hyde and hydrocyanic acid. 



Royal Institution. — On Thursday next, March 11, at 
3 o'clock, Mr. A. D. Hall, Director of the Rothamsted 
Experimental Station, begins a course of two lectures at 
the Royal Institution on " Recent Advances in Agricultural 
Science." The Friday Evening Discourse on March 12 
will be delivered by Mr. S. G. Brown, on " Modern Sub- 
marine Telegraphy " ; and on March 19 by Mr. R. 
Threlfall, on " Experiments at High Temperatures and 
Pressures." 



Chemical News, ' 
March 5, igog 



Chemical Constitution of the Proteins. 



117 



NOTICES OF BOOKS. 



The Chemical Constitution of the Proteins. By R. H. 
Aders Plimmer, D.Sc. Parts I. and II. London, 
New York, Bombay, and Calcutta : Longmans, Green, 
and Co. 1908. 
In this monograph a full account is given of the present 
state of our knowledge of the chemistry of the proteins, 
and as the vast amount of material which could not be left 
unnoticed would have made the monograph exceed the 
prescribed size of the series, it was divided into two parts. 
In the first methods of investigating the proteins are 
treated historically, the isolation of the amino acids and 
the chemistry of the units of which the protein molecule is 
built up are discussed. The second part deals with the 
synthesis of the proteins, and describes fully Fischer's 
masterly work on the polypeptides. This difficult subject 
is made admirably clear and interesting, and is brought 
down to the latest possible date. 



An Intermediate Course of Laboratory Work in Chemistry . 
By Edward Kenneth Hanson, M.A. (Cantab), F.I.C, 
and John Wallis Dodgson, B.Sc.(Lond.). London, 
New York, Bombay, and Calcutta : Longmans, Green, 
and Co. 1908. 
A student who is attending fairly advanced lectures on 
inorganic chemistry will find that this laboratory book 
describes a very suitable course of practical work to 
accompany them. It gives first methods of preparing 
various inorganic compounds. Full directions are in- 
cluded for the experimental work, which sometimes requires 
a good deal of manipulative skill, and illustrations of the 
more complicated apparatus are provided. The substances 
treated include the less common compounds, which would 
not have been studied in an elementary course of practical 
chemistry, and some additional problems are suggested 
for solution. Volumetric work is treated from the com- 
mencement, and some moderately difficult estimations are 
described, besides the usual acid and alkali and oxidation 
titrations. The section on gravimetric work gives the 
typical methods of estimation. The solubility of salts in 
water would most probably have been studied in a pre- 
liminary course, and it would perhaps have been advisable 
to omit the section on this subject and give additional room 
to the consideration of spectroscopic analysis. Finally, 
the qualitative analysis of simple substances is treated in 
outline on a novel plan. The student is told what sub- 
stances to use as group reagents and what confirmatory 
tests to adopt, but in every case he is not told the result of 
the test but is left to construct tables for himself with his 
own laboratory notes to go upon. Thus much haphazard 
work is avoided, and also there is no chance of the quali- 
tative analysis degenerating into blind compliance with 
certain directions which lead to previously explained results. 



Essays, Biographical and Chemical. By Sir William 
Ramsay, K.C.B. London: Archibald Constable and 
Co., Ltd. 1908. 

The essays in this book have either been delivered as 
lectures or published as articles in magazines during the 
last twenty-five years, and it is easy to foretell that their 
publication in book form will bring genuine pleasure to 
many students of chemistry. The style in which they are 
written is delightful, and although the essays on chemical 
and allied subjects in the second part are in a certain sense 
popular and not intended to appeal to a specially trained 
class of readers, they are by no means superficial. The last 
essay on the functions of a university must prove inspiring 
to the most phlegmatic, and all teachers, even of elementary 
classes, will learn valuable lessons from it as to what 
should be the aim of all scientific instruction. The earlier 
essays deal with the history of chemistry and relate to 



various periods, all of which are treated with the same 
insight and illuminative descriptive power. The essay on 
the early days of chemistry deals with the knowledge of 
the ancients, and that on the great London chemists with 
the special claims to renown — Boyle, Cavendish, Dayy, 
and others. Of more recent heroes of science one essay 
discusses the life and work of Lord Kelvin, and another 
has for its subject Berthelot ; both are marked by a whole- 
hearted and generous recognition of the great qualities of 
these two famous men, and of the immense value of the 
results of their labours which were given to the world: 



The Toil of Life. By Francis Stopford. Second 
Edition. London and Felling-on-Tyne : The Walter 
Scott Publishing Co., Ltd. 1908. 
This is a book which undoubtedly contains a message for 
the toilers of the earth, to whom it is dedicated, and every 
thinking person will find profit in pondering over its 
theories. The author's simple straightforward philosophy 
is refreshing and at the same time stimulating, and there is 
a charm about the book which is irresistible. A preface 
has been added to the second edition, explaining what was 
the source and inspiration of the original, and giving a 
further insight into the author's exalted views on the 
meaning of life. 



The Chemical Analysis of Iron. By Andrew Alexander 
Blair. Seventh Edition. Philadelphia and London : 
J. B. Lippincott Company. 1908. 
The alterations made in the seventh edition of this 
standard work on the analysis of iron are comparatively 
trifling, but at the same time they all make for the greater 
efficiency and value of the book. New methods of sepa- 
rating vanadium, molybdenum, chromium, and nickel in 
steel, which have been worked out recently, are now in- 
cluded. In the case of vanadium the author recommends 
Campagne's method as being simple, accurate, and rapid. 
Also the volumetric method of determining nickel by titra- 
tion with a standard solution of potassium cyanide, which 
has been found to give very satisfactory results, is described. 
The atomic weights throughout the book have been altered 
in accordance with the report of the International Com- 
mission for 1908, and all factors have been recalculated 
when necessary. 



Photographic Optics and Colour Photography . By George 
Lindsay Johnson, M.A., M.D., B.S., F.R.C.S. 
London : Ward and Co. 1909. 
An excellent treatment of both the practical and theoretical 
side of optics is given in this book, every page of which 
shows that its author has a special knowledge of the sub- 
ject. It opens with a description of the various kinds of 
cameras, explaining the working of different types, and 
the special merits of each, and here the author's experience 
of the instruments of different makers enables him to give 
valuable advice on practical details. The lens is next 
considered, and in these chapters the mathematics intro- 
duced are simplified as far as possible, and practical 
problems are illustrated by simple examples which are 
worked out in full ; these typical examples have been 
carefully chosen to include all kinds of problems, and are 
explained remarkably clearly. Methods of testing lenses 
and their use for magnifying and reducing, and many 
special problems in photography are next considered, such 
as the measurement of the speed of a shutter. Finally, a 
very lucid account is given of the present state of colour 
photography, in which ihe different processes are explained 
in language which cannot fail to be understood. Excellent 
reproductions are given of photographs in colour, and for 
this part alone the book is well worth procuring and 
reading. The author's hints on photography, on the 
management of the plate and its development, will be 
appreciated by the amateur, and even the professional 



ii8 



Chemical Notices from Foreign Sources, 



Chemical News, 
1 March 5, igog 



cannot afford to ignore the valuable suggestions which are 
scattered through the book, which is a thoroughly modern 
text-book on applied optics. 



Die Elektrischen Eigenschaften und die Bedeutung des 
Selens fur die Elektrotechnik." (" The Electrical Pro- 
r perties and Importance of Selenium in Electro-technics ") . 
By Dr. Chr. Ries. Berlin: Administration der Fach- 
• zeitschrift " Der Mechaniker." 1908. 
The properties of selenium, which are particularly in- 
teresting both from a scientific and technical point of view, 
are exhaustively treated in this monograph, which gives an 
excellent summary of all that is at present known of the 
element. The preparation of selenium cells is discussed 
in the early part of the book, and the influence of tem- 
perature upon electrical conductivity is treated fully. The 
importance of selenium in electro-technics is eonstantly 
emphasised, and many graphical representations of the 
variations in its sensitiveness to light, conductivity, &c., 
arc reproduced in order to make the subject clear. A 
summary of the literature of selenium includes all im- 
portant books and articles which have been published 
dealing with its physical or chemical properties, and has 
been brought down to the year 1908. 



CHEMICAL NOTICES FROM FOREIGN 
SOURCES. 



NoTl. — All dci;ree» of temperature mre Centieiade unless atherwls.- 
expres»«d. 

Comptes Rendus Hebdomadaires des Seances de VAcademie 
des Sciences. Vol. cxlviii.. No. 4, January 25, igog. 
New Method of Preparing Alcoholic Oxides. — 
J. B. Senderens. — Alumina obtained by precipitating 
sodium aluminate with sulphuric acid dehydrates alcohols, 
giving alcoholic oxides. At 200** alumina begins to decom- 
pose ethyl oxide, and it yields large quantities of ethylene 
at 300°. If the temperature is kept below that at which 
the ethyl oxide is destroyed, the latter can readily be 
obtained by condensing the products of the reaction and 
allowing the liquid obtained to stand for some time. Thus 
two layers of liquid are obtained, the lower being water 
containing about one-tenth of its volume of ethyl oxide, 
and the upper ethyl oxide containing a very small quantity 
of water. 

Condensation of Mesoxalic Ethers with Tertiary 
Aromatic Amines. — A. Guyot and E. Michel. — Aromatic 
amines combine with alloxan without elimination 
of water, the general formula of the products being 

^*^^NH— CO-^^^OH' ^^"® ^ '^ phenyl, naphthyl, 
&c. Under the action of aqueous alkalis these products 
split up into substituted tartronic acids, carbon dioxide, and 
ammonia : — 

CO<SgzgC>CC:gH+3HaO = 



R 



COjH 



=.CO.-|-2NH3 + ^j^O>CC--»y. 

These tartronic acids, when treated with hot concentrated 
sulphuric acid give the corresponding aldehydes quantita- 
tively, R— C0H(C02H)2 = R— COH i- CO2 -J- CO -|- H^O. 
With oxidising agents they give glyoxyllic acids, 
and when heated alone or in aqueous solution they 

five up carbon dioxide, yielding glycollic acids, 
I— C0H(C02H)a = CO2 f R.CHOH.CO2H. 

No. 5, February i, igog. 
New Reactions of Dioxyacetone. — G. Deniges. — 
W^cn dipxyi^cetone is prepared from glycerin by the 



action of bromine, it gives certain colour reactions which 
are very characteristic, if it is not separated from the 
medium in which it has been formed. Thus, a strawberry- 
red coloration is obtained with salicylic acid, and a dark 
violet with gallic acid. These reactions are not due to 
glyceric acid, the corresponding aldehyde, nor to glycerin 
itself, but are produced by the bromine set free by the 
action of concentrated sulphuric acid on hydrobromic acid 
mixed with dioxyacetone, and derived from the action of 
the halogen on the glycerin. 

Action of Air and Oxidising Agents on Coal. — O. 
Boudouard. — The author has determined the change of 
weight of various specimens of coal when subjected to the 
action of air at different temperatures, also to the action 
of nitric acid, and has found that the increase of weight 
observed is due to the absorption of oxygen. The pheno- 
menon is more noticeable when the temperature is raised. 
Coking coals when oxidised at 100° completely lose their 
coking power, and, moreover, they then contain humic 
acid which was not present previously. A more energetic 
oxidising agent such as nitric acid gives a larger proportion 
of humic acid. 

Formation of Hydrocyanic Acid by the Action of 
Nitric Acid on Phenols and Quinones. — A. Seyewetz 
and L. Poizat. — Twenty per cent nitric acid when boiling 
oxidises many aromatic compounds, setting free hydro- 
cyanic acid. This action takes place only in presence of 
a phenol or quinone group, and it is only those compounds 
which have the para-position free, or the two ortho-positions 
free, which liberate HCN. Nitrous acid is also always 
formed, and substances which destroy nitrous acid, e.g., 
urea or aniline, stop the formation of hydrocyanic acid. 
The nitrous acid first yields a para- or ortho-nitroso- 
derivative, and then oxidation occurs at the double bond, 
and mesoxalic acid and the oxime of the acid are formed, 
or else carbon dioxide, oxalic acid, and the monoxime of 
dioxytartaric acid. The mesoxalic or oxalic acids then 
give up carbon dioxide, and the oxime condenses, 
evolving hydrocyanic acid. 

Action ot Nitrosobenzene upon Secondary Amines. 
— P. Freundler and M. Juillard. — Nitrosobenzene reacts 
energetically with secondary amines, being transformed 
chiefly into azobenzene. Some nitrobenzene, aniline, and 
probably a little azoxybenzene are also formed. The 
greater part of the amine remains unaltered. Under 
certain conditions a secondary hydroxylamine, RR'NOH, 
is formed. The authors have observed that isoamylamine 
is soluble in water in all proportions. Methylisoamyl- 
amine is hardly soluble, but if to equal volumes of the 
secondary base and water one-fourth or one-fifth of primary 
amylamine is added, the mass becomes homogeneous. If 
the mixture is heated to 50° the secondary base separates 
completely, taking with it most of the primary amine. 
The authors think that methylisoamylamine forms a 
hydrate soluble in aqueous solutions of the primary base. 
This hydrate, which loses its water on heating and 
becomes insoluble, undoubtedly exists, for methyliso- 
amylamine absorbs water with a rise of temperature, and 
when the homogeneous liquid thus obtained is heated 
water again separates. 

Reactions of the 9 . 10 Dihydride of Anthracene 
and of Anthranol. — R. Padova. — When heated with 
sulphur to 200° the dihydride of anthracene gives anthracene. 
It does not condense with aromatic aldehydes, and does 
not react with benzylidene chloride nor with phenyl 
chloroform in xylene. When it is heated with phenyl 
chloroform and powdered marble, resinous products are 
obtained. Anthracene dihydride condenses with benzo- 
phenone chloride, giving tetraphenylanthraxylilene. Chloro- 
form and alcohol potash give a red crystalline substance, 
the analysis of which shows that it is lo-oxanthryl-g- 
anthraquinone methane. 



Chemical Nbws, 
March 5, 1909 



Chemical Notices from Foreign Sources. 



119 



Berichte der Deutschen Chetnischen Gesellschaft. 
Vol. xlii., No. I, igog, 
Selenous Mercaptans and some of their Deriva- 
tives. — L. Tschugaeff. — To prepare selenous mercaptans, 
sodium hydroselenide solution is treated with the bromide 
or iodide of an alcohol radical in an atmosphere of 
hydrogen ; the liquid is heated on the water-bath, poured 
into water, and the oil which separates is shaken with 
caustic soda solution, when the mercaptans formed go into 
solution. They may be set free by acetic acid. The 
selenous mercaptans are heavy colourless liquids which 
react with mercury oxide, and give characteristic coloured 
precipitates with all salts of the heavy metals in aqueous or 
alcoholic solution, the orange precipitates with lead and 
thallous salts being specially characteristic. The selenous 
mercaptans are autoxidisable substances, giving diselenides 
inair. 2C2H5.SeH f i02 = C2H5.Se2.C2H5 + H20. They 
react with magnesium methyl iodide as follows : — 
R.SeH + CHj.Mgl = R.SeMgI + CH4. Selenides of 
formula R1.Se.R2 can be prepared by treating mercaptans 
in absolute alcohol with sodium alcoholate, and then adding 
the bromide or iodide of the corresponding alcohol radical. 
Diselenides of general formula R.Se.(CH2)«.Se.R result 
from the action of the dibromides, Br.{CH2)«Br, on 
the sodium derivatives of selenous mercaptans, 
2NaSeR+Br.(CH2)n.Br = R.Se.(CH2)n.Se.R+2NaBr. 

a - Methylisoxazol. — L. Claisen. — When hydroxyl- 
amine acts on oxymethylene acetone, methylisoxazol is 
formed, C4H6O2 + NH2.OH = C4H5NO + 2H2O. The pro- 
duct, however, is not a single substance but a mixture of 
two isomers, o-methyl and 7-methylisoxazol, — 

CH— CH CH— C.CH3(7) 

II II II II 

(a)CH3.C N and CH N 

Y Y 

The a-derivative boils at 122° and the y-derivative at 118°. 
The former is converted by alcoholic sodium ethylate into 
sodium cyanacetone, — 

CH3.C:CH.CH:N + NaOC2H5 = 
O ' 



= CH3.C(ONa):CH.CN + C2H5.0H, 

and the latter yields acetic acid and acetonitrile. The two 
corresponding acids, — 

CH3.C:CH.C.C02H CHj.C.CHiC.COaH 
I II and H I 

O N N O 

have been prepared. The compound obtained by Schmidt 
and Widmann from diacetosuccinic acid ester, and thought 
by them to be isoxazol, has undoubtedly not the com- 
position they ascribe to it, nor does it appear to be 
cyanacetone. 

Polymerisation as a cause of the Difference of 
Colour of Haloid Salts and Sulphites. — A. Hantzsch. 
— Many inorganic haloid salts are more or less strongly 
coloured, while the corresponding salts of strong oxyacids, 
e.g., nitrates, chlorates, sulphates, perchlorates, &c., are 
colourless. The same phenomenon is observed with some 
organic salts, and is specially marked with the acridine 
bases. The explanation based upon the auxochrom theory 
is not satisfactory, and the author ascribes the differences 
of colour to a chemical cause, namely, polymerisation. 
He has not as yet deduced specific relations between the 
constitution of salts and their power of forming dark 
coloured polymers, but it may be stated generally that 
polymerisation occurs more readily the more unsaturated 
the cation is and the more loosely the anion and cation 
are bound together. 

Volatility of Arsenic and Thallium in vacuo. 
Method of Calculating the Boiling-point of Metals. — 
F. Krafft and A. Knocke. — A specimen of arsenic kept 



in vacuo for twenty-four hours at room temperature showed 
no loss of weight. Hence, arsenic is not volatile at the 
ordinary temperature. Volatilisation begins in a vacuum 
at g6° and rapid sublimation at 325'. At a temperature 
of 554 — 556° arsenic sublimes under a pressure of 760 mm.., 
and when these data are compared the following result is 
obtained : — 

Incipient volatilisation, o mm. . . 06° 1 r^-a « 

Sublimation, o mm 325° 5-5"*"" "^I 

Sublimation, 760 mm 55;° } Difference 229' 

For any metal given any two of these constants, the third 
can be calculated. In the case of thallium, evaporation 
begins under o mm. at 174°, and the boiling-point under 
o mm. is 818°. The difference, 644°, added to 8i8*, gives 
the boiling-point under 760 mm., viz., 1462°. 

Evaporation of Non-volatile Metals, especially 
Platinum and Iron, in Evacuated Glass Vessels. — A. 
Knocke. — The least volatile metals can be volatilised 
in vacuo at comparatively low temperatures in glass 
vessels. Experiments with the metals of the alkaline 
earths show that strontium is somewhat more volatile than 
calcium, and barium, which has the highest atomic weight, 
is also the most volatile of the three alkaline earth metals. 
Platinum volatilises rapidly in a vacuum at 700° and 
palladium at 735°. Of the metals of the iron group, cobalt, 
with higher atomic weight, evaporates much more easily 
than iron, and nickel lies between the two metals in this 
respect. 

Colloidal Potassium Chloride.— C. Paal and Kurt 
Zahn.— The solid organosols of potassium chloride, pre- 
pared either by precipitation from their colloidal solutions, 
or directly, and the KCl gels, like the corresponding 
sodium salts, are adsorption compounds. These adsorp- 
tion compounds of potassium chloride exist in five different 
modifications, solid and liquid organosol, liquid gel, solid 
reversible gel soluble in benzene, and solid irreversible gel. 
These modifications can be prepared in the same way as 
the corresponding compounds of sodium chloride- 



MISCELLANEOUS. 

The Universal Crucible Support.— (Designed by 
G. T. HoLLowAV, and made by J. J. Griffin and Sons, 
Ltd.). — The device consists of a set of three sliding rods 
pointed with quartz. The rods pass obliquely through the 
legs of a suitable tripod, and are held firmly in their correct 
positions by the action of strong brass springs. They may 




be adjusted to support crucibles and vessels of any shape 
or material with the greatest ease. The little pointed caps 
are made of pure silica, and do not break the f!ame. They 
are of course incorrodible in the ordinary seiise of the word, 



12^' 



Meetings for the Week. 



{Chemical f>JB^s< 
March 5, 19090* 



and may therefore be safely used with platinum crucibles. 
There being only three points of contact, ihe contents of 
the crucibles are heated uniformly, and there is no necessity 
to turn the crucible round to complete an ignition, as must 
be done when using an ordinary pipeclay triangle. The 
support is practically indestructible, and should find a 




place in every laboratory. The three silica points will 
enclose a circle 3 in. diameter. For use with quartz 
crucibles and capsules it is incomparable. This combined 
apparatus is always ready. It is less costly than a tripod 
and platinum triangle combined, and its reliability and 
convenience are obvious. 

Fresenius Chemical Laboratory in Wiesbaden. — 
Vacation Courses have been recently established ; the first 
of these was given in the autumn of 1908 ; the students 
numbered 10. During the current Winter Term, 1908- 
1909, the laboratory was attended by 25 students, among 
whom was i lady. Of these, 12 were from the German 
Empire, 3 from Austria-Hungary, 3 from the United States 
of Moith America, 2 from England, and i each from 
Switzerland, Luxemburg, Belgium, Norway, Russia, East 
India, and Japan. In addition to the directors, Geheimer 
Regierungsrat, Prof. Dr. H. Fresenius, Prof. Dr. W. 
Fresenius, and Prof. Dr. E. Hintz, there are five teachers 
and heads of departments, two assistants in the Instruction 
Laboratories, and twenty-two assistants in the private 
laboratories. The next Summer Term begins on April 26th 
of this year. During the Winter Term a number of 
scientific researches were published from the Laboratory. 
The various articles appeared in the chemical periodicals, 
especially in the Zeitschrift fur Analytische Chernie, 
which is edited by the directors of the Laboratory. In 
addition to the scientific researches during the Winter 
Term of 1908-1909, numerous analyses were made In the 
different departments of the Laboratory in the interest of 
trade, mining, industry, agriculture, hygiene, justice, and 
government. 



MEETINGS FOR THE WEEK. 



Mbnday, 8th.— Royal Society of Arts, 8. (Cantor Lecture). " Modern 

Methods of Artificial Illumination," by Leon Gaster. 

TuBSDAY, gth.— Royal Institution, 3. " Evolution of the Brain as 

an Organ of Mind," by Prof. F. W. Mott, F.R.S. 
Wednesday, loth.— Royal Society of Arts, 8. " Application of the 
Microscope to the Study of Metals," by Walter 
Rosenhain. 

Thursday, nth.— Royal Institution, 3. " Recent Advances in Agri- 
cultural Science," by A. D. Hall, M.A. 
Friday, lath.— Royal Institution, 9. "Modern Submarine Tele- 
graphy," by Sidney G. Brown, M.I.E.E. 
— — Physical, 8. •' Effect of Radiations on the Brush Dis- 

charge," by A. E.Garrett. "On Pirani's Method 
of Measuring the Self-inductance of a Coil," by 
E. C. Snow. Exhibition of a High Potential 



Primary Battery, by W. S. Tucker. " On the Least 
Moment of Inertia of an Angle Bar Section," by 
H. S. Rowell. 
Saturday, 13th. -Royal Institution, 3. "Properties of Matter," by 
Prof. Sir J. J. Thomson, F.R.S. 



NOW READY. Cloth, SjG ; Paper covers, 216. 
(Postage, 4d. extra). 

THE WHEAT PROBLEM: 

Based on Remarks made in the Presidential Address 
to the British Association at Bristol in 1898. 

REVISED WITH AN ANSWER TO VARIOUS CRITICS 

By SIR WILLIAM CROOKES, F.R.S. 
SECOND EDITION. 

VITH PREFACE AND ADDITIONAL CHAPTER, BRINGING THE 
STATISTICAL INFORMATION UP TO DATE. 

With Two Chapters on the Future Wheat Supply of the 

United States, by Mr. C. Wood Davis, of Peotone, 

Kansas, and the Hon. John Hyde, Chief Statistician 

to the Department of Agriculture, Washington. 

OPINIONS of the PRESS. 

" Sir William Crookes . . has propounded a problem 
which in the next century [written in 1899] is bound to 
engage the close attention not merely of agricultural 
experts, but of economists and statesmen." — Speaker. 

" The appearance of the papers in this convenient form 
will be welcome to everyone who appreciates the import- 
ance of the problem." — Scotsman. 

" If these somewhat gloomy prognostications result in 
drawing the attention of chemists more seriously to what 
has hitherto been only an interesting laboratory problem, 
Sir William Crookes will have conferred an incalculable 
benefit on the race." — Western Morning News. 

" The student of economic science and sociology will find 
this volume full of interesting material. . . The entire 
subject is of the profoundest interest, and an excellent pur 
pose has been served by the publication of these papers in 
a single volume." — The Eagle (Brooklyn, N.Y.). 

" In his bulky volume Sir William reproduces the gist 01 
the sensational Bristol Address, and supplements it with 
carefully prepared answers to his chief critics and confirm- 
atory chapters on the future wheat supply of the United 
States." — Morning Post. 

" The fuller examination of the problem as here conducted 
shows that Sir William Crookes did not speak unadvisedly 
with his lips." — Yorkshire Post. 

" The problem is one of importance, and Sir William 
Crookes presents it to us fortified by the opinions of two 
American experts." — Manchester Guardian. 

" Sir William Crookes's statistics seem to make good his 
alarmist statement." — British Weekly. 

" In the present volume Sir William Crookes replies 
vigorously to his critics." — Liverpool Daily Post. 



CHEMICAL NEWS OFFICE. 
16 NEWCASTLE ST., FARRINGDON ST., E.G. 



COVER S FOR BI NDlf^G. 

Cloth ,Gilt<lettered Covera for Binding the Half-yearly 
Volumes of the 

CHEMICAL NEWS 

may now be obtained, Prict 1/6 *ach {post free 1/8). 

VolumcB Bound in Cloth CaseB, Lettered and Numbered 
at 21.6(1. per volume 

16. M££WCAbTL ST., FARRINGDON ST., B.C. 



Chemical Kews, i 
March 12, 1909 < 



isolation and Synthesis of Urea. 



121 



THE CHEMICAL NEWS 



Vol XCIX., No. 2572. 



THE ISOLATION AND SYNTHESIS OF UREA. 
By F. D. CHATTAWAY, F.R.S. 

Among the almost bewildering number of compounds 
known to chemists there are few, if any, which surpass 
urea in interest. 

This is obvious whether one considers the part it has 
played in the development of organic chemistry and the 
number of well-known compounds which can be made 
irom it, or the circumstance that it is the form in which 
nitrogen is mainly excreted. 

There is no animal matter which has been subjected to 
a more rigorous examination than urine, and it is some- 
what of a surprise to find that urea, which is its most im- 
portant constituent, was not properly isolated till the close 
of the eighteenth century. During the preceding century, 
chemists from the time of Boerhaave (1668 — 1738) to 
that of Scheele (1742 — 1786) almost exclusively occupied 
themselves with the phosphates which are contained in it. 
This great attention to the phosphates arose from the 
interest inspired by the discovery of phosphorus, which 
was obtained originally by strongly heating with white sand 
the residue left after evaporating urine. Scheele even 
failed to notice the presence of urea in urine. He, how- 
ever, was chiefly concerned with the uric acid contained 
in it. It is worth noting that it is not necessarily the sub- 
stance present in largest amount in any natural product 
which is first discovered, but the one which is most easily 
isolated, and hence generally the insoluble or least soluble 
part. 

Urea appears to have been noticed first in 1773 by 
Rouelle* the younger, and styled the " saponaceous extract 
of urine." It was, however, first definitely isolated by 
Fourcroy (1755 — 1809) and Vauquelin (1763 — 1829), who in 
1799 and 1800 published two memoirs upon the constituents 
of urine [Annales de Chimie, 1799, xxxi., 49 ; 1800, xxxii., 
80). They state that, although they have searched through 
the works of all authors who have written upon urine, they 
cannot find any precise information which could refer to 
this body before 1773. 

Boerhaave, of Leyden, in speaking of the evaporated 
residue, states that it resembles honey in appearance, but 
Rouelle was the first to make any express mention of a 
distinct substance and to give a few of its characters, pub- 
lishing his observations in November, 1773, in the Journal 
de Medecin. 

Fourcroy and Vauquelin obtained urea in a state of 
comparative purity by evaporating urine and extracting the 
syrupy residue by alcohol. The alcohol was distilled off, 
and the solution left to cool, when crystals separated ; 
these were purified by repeated crystallisation from water, 
or better from alcohol. They recognised their product as 
a definite new compound, and described many of its more 
obvious properties. They gave it the name of "uree," 
which they say connects it in the mind with urine from 
which they had obtained it. 

During the next twenty years urea was prepared by a 
number of chemists, but evidently their methods still left 
something to be desired, for Dr. William Prout, in 1818, 
devised an improved process. His paper was published in 
the eighth volume of the Med. Chir. Transactions, and the 
part dealing with urea is reprinted in Thomson's " Annals 
of Philosophy," 1818, xi., 352. 

♦ Hilaire Marin Rouelle (1718— 1779), brother of the more celebrated 
Guillaume Francois Rouelle (1703—1770) who was one of the most 
eminent of the French chemists of the eighteenth century, and the 
teacher of Lavoisier, J 



He obtained urea by evaporating urine to the con- 
sistency of syrup and adding nitric acid till the whole was 
converted into a crystalline mass. This was washed 
slightly with cold water, and the nitric acid then neutralised 
by a solution of potassium or sodium carbonate. The 
greater part of the potassium or sodium nitrate was then 
removed by crystallisation, the mother-liquor was made 
into a paste with animal charcoal, and the urea dissolved 
out from this by cold water. This aqueous solution was 
next evaporated to dryness and the urea extracted by 
alcohol. To obtain it perfectly pure it was necessary to 
re-crystallise it several times from alcohol. Having thus 
prepared pure urea Prout described its properties very 
carefully and analysed it. He does not give any details 
of the method used, but says " The substance under ex- 
amination was heated with oxide of copper in an apparatus 
so contrived that the amount of water and carbonic acid 
formed might be accurately ascertained and the carbon 
and hydrogen thus estimated while the azote remained 
uncombined." 

The accuracy of his results, considering the time at 
which the analysis was made, is remarkable. He deter- 
mined the percentage composition to be — H » 6-66, 
C = 19-99, N = 46-66, O (by difference) 26-66 ; the per- 
centage composition calculated from the formula, using 
the most recent international atomic weights, being — 
H=6-7i, = 19-96, N = 46-7i, = 26-62. 

Some years later large quantities of urea were required 
in the hospital of St. Antoine in Paris for making experi- 
ments (which were unsuccessful) as to its efficacy as a 
therapeutic agent in cases of diabetes, and M. Henry, who 
was charged with making it in the Central Pharmacy of 
the Civil Hospitals of Paris, devised a somewhat less 
troublesome method of obtaining it in quantity (yourttal 
de Pharmacie, 1829, xv., 161). 

Henry suggested that a slight excess of subacetate of 
lead or hydrate of lead, either of which precipitates the 
acids of the salts contained in it and much of the mucous 
and animal matter, should be added to fresh urine. The 
precipitate having been filtered off and any dissolved lead 
removed by adding dilute sulphuric acid, the liquid was 
concentrated, animal charcoal being added during ebul- 
lition, and filtered ; the filtrate was then further evaporated 
till crystals separated ; these were mixed with a little dry 
sodium carbonate and the urea extracted by alcohol. The 
product was finally re-crystalllsed from water. 

This practically concludes the important work on the 
preparation of urea from urine, the problem having been 
to separate it from the uric acid, phosphates, and animal 
matters contained in this fluid. It is still always prepared 
by processes not essentially differing from those of Prout 
and Henry, either by removing the urea irom the concen- 
trated urine as a sparingly soluble salt such as the nitrate 
or oxalate, the other constituents remaining behind in the 
mother-liquor, or by precipitating the other constituents by 
oxide of lead, thus leaving the urea and little else in the 
filtrate. 

This carries the history of the compound to the period 
of one of those great discoveries which from time to time 
alter the whole outlook of chemistry. Organic chemistry 
dates from it in two senses ; it broke down the barrier 
between organic and inorganic chemistry, and was the 
first example of organic synthesis. 

At this time, 1828, a very large number of well-defined 
substances obtained from animal and vegetable sources 
had become thoroughly well known ; they had been analysed 
and the fact established that in spite of a great diversity in 
properties they were composed of a very few elements. 
The more these substances were studied the more evident 
it became that they possessed no peculiar characteristics 
which distinguished them from compounds of mineral 
origin ; thay had the same constancy of composition as 
inorganic compounds, and their constituent elements were 
present in the proportions required by their atomic >veights. 
Almost all chemical and physical properties were common 
to both classes ; only in one particular did substances of 



122 



Isolation and Synthesis of Urea. 



{ Chbuical Nbws, 
I March I2, 1909 



animal or vegetable origin differ from substances obtained 
from non-organic sources — they could not be built up from 
their constituent elements in the way most inorganic 
substances could. 

This is, however, such a fundamental difference that one 
is not surprised that many chemists of the time thought 
that these bodies must be elaborated in animals and plants 
under conditions which could not be realised outside such 
living organisms. The processes by which they were 
formed appeared so mysterious that a peculiar force, the 
" vital force " or " lebenskraft " was called into existence to 
explain them. It is difficult to trace the origin of this 
conception ; it probably arose from the idea that some 
particular substance active only during life was common 
to all living matter, and that this living material was 
necessary to the formation of all organic compounds. 

The idea that there exists an essential difference in nature 
between organic and inorganic compounds was shown to 
be untenable when Wohler effected the synthesis of urea. 
This discovery so changed the direction of chemical thought 
and opened up such wide possibilities that the paper in 
which it is described, in spite of its confused style and 
frequent repetition, takes rank as one of the most notable 
ever written. It was published in 1828 in Poggendorf s 
Annalen der Physik unci Chemie, 1828, xii., 253, under the 
title " Ueber Kiinstliche Bildung des Harnstoffs," and no 
apology is needed for quoting from it a free rendering 
of Wohler's own words : — 

"A crystalline white substance ... is invariably 
obtained whenever one attempts, for example, by so- 
called double decomposition to combine cyanic acid 
with ammonia. The circumstance that on combination 
these substances appear to alter their nature and that a 
new compound results has turned afresh my attention to 
the subject. The investigation has led to the unexpected 
conclusion that urea is formed by the union of cyanic acid 
and ammonia. This observation is especially noteworthy, 
as it affords an example of the artificial production of an 
organic and indeed of a so-called animal substance from 
inorganic material. I have further noticed that the above 
mentioned white crystalline body is best obtained either 
by decomposing cyanate of silver by a solution of sal- 
ammoniac or lead cyanate by liquid ammonia. I prepared 
the considerable quantity required for its investigation in 
the latter manner. I thus obtained it in clear colourless 
crystals often more than an inch long, which formed 
slender rectangular four-sided prisms without definitely 
pointed ends. When this substance was heated with 
potash or with lime no trace of ammonia was liberated. 
With acids it did not show the characteristic behaviour of 
cyanates which when thus treated yield carbonic and 
cyanic acids. Further, it did not, as true salts of cyanic 
acid do, give a precipitate with salts of silver and lead. 
It could, therefore, contain neither cyanic acid nor 
ammonia as such. 

" As I found that in the last named method of preparation 
nothing was formed beside it except pure lead oxide, I 
drew the conclusion that by the union of cyanic acid and 
ammonia an organic substance was produced perhaps 
■imilar in nature to the vegetable salt-forming bases. 
With this idea in my mind, therefore, I set on foot an 
investigation into the behaviour of the crystalline body 
towards acids. It, however, showed itself indifferent to 
these except to nitric acid, which when added to a con- 
centrated solution at once produced a precipitate consisting 
of glittering scales. These after being purified by frequent 
re-crystallisation showed such a marked acid character 
that I was inclined to regard them as a peculiar acid when 
Ifound that on neutralising them by bases they yielded 
salts of nitric acid from which the crystalline material in 
question could again be extracted by alcohol, with all the 
characteristics it possessed before being acted upon by the 
nitric acid. This behaviour, so strikingly similar to that of 
urea, induced me to compare it with perfectly pure urea 
separated from urine. This comparison established beyond 
doubt that the crystalline body or cyanate of ammonia, if 



one may call it so, and urea are one and the same 
substance." 

He adds in conclusion, " I refrain from putting forward 
here the reflections which naturally present themselves as 
a consequence of the fact here established that compounds 
of the same elements having the same composition may 
possess very different properties." 

Berzelius, referring to Wohler's discovery in the ninth 
issue of the yahresbericht, is much clearer. He states :— 
" One of the most unexpected, and on that account most 
interesting, of recent discoveries in the department of 
animal chemistry is incontestably Wohler's artificial pro- 
duction of urea. This chemist finds that when silver 
cyanate is treated with a solution of ammonium chloride 
or lead cyanate with ammonia, a crystalline substance is 
formed, which possesses to the slightest detail all the pro- 
perties of pure urea, and is, in fact, urea itself. Urea, 
however, is not on that account to be regarded as am- 
monium cyanate ; the elements are united in it in a different 
way, so that the strongest bases can no longer liberate 
ammonia from it, nor the strongest acids set free cyanic 
acid. One can only say that this substance has changed 
from a compound inorganic atom of the second order to a 
compound organic atom of the first order. This fact 
affords a key to many difficulties, and shows that the same 
number of simple atoms distributed among themselves in 
dissimilar ways in compound atoms can give rise to bodies 
with different properties." 

The course of the reaction which takes place when 
ammonium cyanate passes into urea has never been 
explained. Liebig and Wohler later showed that the 
reverse change could be effected, and that when urea is 
mixed with an aqueous solution of AgNOa ^"<^ evaporated 
to dryness, it is completely resolved into ammonium 
nitrate and cyanate of silver. Walker has recently shown 
that the transformation of ammonium cyanate into urea is 
a reversible action, and that equilibrium is reached at 100° 
when about 5 per cent of the urea is changed. 

Although the fact that urea is easily broken down into 
carbon dioxide and ammonia when heated with acids or with 
alkalis led chemists, as soon as molecular structure began 
to be considered, to regard it as the amide of carbonic acid, 
this view was not supported by any direct synthesis of the 
compound from derivatives of the acid until Natanson, 
nearly thirty years after Wohler's work, obtained it by the 
interaction both of the chloride and of the ethyl ester of 
carbonic acid with ammonia. 

Natanson in his paper (" Ueber zwei Kiinstliche 
Bildungsweisen des Harnstoffs, Ann., 1856, xcviii., 287) 
describes his experiments as follows : — " If ethyl carbonate 
is heated with ammonia in a sealed tube at 100° urethane 
only is formed, but if the temperature is raised to about 
180°, the latter through the action of the excess of ammonia 
is converted into urea. In the part of the tube not filled 
by the liquid, a sublimate of undecomposed urethane is 
formed, while the aqueous solution contains the urea. 
When this solution is evaporated to dryness and the residue 
heated for some time to 100*, most of the urethane re- 
maining volatilises, and urea, which can be immediately 
recognised by its reaction with nitric acid, remains behind." 
Completely to remove the last traces of urethane the urea 
was washed with ether, in which the former compound is 
easily soluble. The urea thus obtained was analysed 
and compared with natural urea, with which it was found 
to correspond in every respect. 

Much earlier, Regnault (Ann. Chitn. Pkys., 1838, Ixix., 
180) had investigated the white neutral substance produced 
when dry phosgene and ammonia are brought together, 
and had shown that it behaved in some of its reactions as 
a mixture of sal-ammoniac and the amide of carbonic acid. 
He, however, concluded that the carbamide which he 
believed to be present was not identical with urea, since, 
on adding strong nitric acid to a saturated solution of the 
white mixture, nothing separated, while urea nitrate was 
at once precipitated on similarly treating a solution 
of urea. 



Chemical News, | 
March 12, 1909 I 



Isolation and Synthesis of Urea. 



123 



Natanson re-investigated the reaction between carbonyl 
chloride and ammonia, and found urea in the white solid 
product which he obtained. He showed that if the gases 
were not thoroughly dried before being mixed, the amount 
of iirea formed was so much diminished relatively to the 
amount of sal-ammoniac that it could not be recognised by 
adding nitric acid, which only throws down urea nitrate 
froh) a sufficiently concentrated solution of urea. Natanson 
describes his procedure as follows : — " I prepared the 
phosgene gas required for the investigation by leading 
carbon monoxide through boiling antimony perchloride. 
This method, recommended by Hofmann (Ann., 1849, 
Ixx., 139), I found very convenient. The two gases were 
led into a spacious dry glass balloon. The presence of 
urea in the white solid obtained could be shown, even by 
extracting it with absolute alcohol, evaporating the 
alcoholic extract to dryness, dissolving the residue in a 
little cold water, and adding strong nitric acid ; urea nitrate 
separated at the latest in a few hours. All the urea formed 
can be obtained by adding a solution of baryta to the white 
solid product in sufficient excess to decompose the whole 
of the sal-ammoniac, evaporating the resulting liquid to 
dryness over sulphuric acid under the receiver of an 
air pump, and extracting the residue by absolute 
alcohol. The alcoholic extract having been evaporated to 
dryness and dissolved in a little water, sufficient ammonium 
carbonate must be added to precipitate any barium salt 
present. By adding strong nitric acid the urea can then be 
separated as its nitrate after sufficiently concentrating the 
filtrate. The treatment with ammonium carbonate cannot 
be omitted, because barium nitrate, which would be formed 
if the barium salts were not removed, is only very sparingly 
soluble in excess of nitric acid. The excess of ammonium 
carbonate used is mainly volatilised during the concentra- 
tion, any small quantity which may remain in no way 
interferes with the reaction, as ammonium nitrate is very 
easily soluble in nitric acid." The precipitate thus obtained 
Natanson showed to be urea nitrate by analysis and by 
comparing its properties and behaviour with the salt other- 
wise prepared. He also isolated urea from it by decom- 
posing it with potassium carbonate, and showed this to be 
identical with that obtained from urine. 

Although the exact constitution of urea gave rise to some 
discussion at the time when opinions regarding molecular 
structure were settling down into their present form, the 
view now universally held, that urea is the amide of carbonic 
acid and of symmetrical structure, was established by 
Natanson's work, and no objection deserving of serious 
attention has ever been made to it. The arguments which 
have from time to time been brought forward in favour of 
an unsymmetrical structure have been based upon a want 
of sufficient recognition of the fact that a complex molecule 
is not a rigid structure, and that every part affects the 
affinities and relationships of every other part. The two 
NH2 groups of urea ought not therefore to be expected to 
behave alike in all reactions, for since, in any given 
reaction, one must be first attacked, from this moment 
the properties of the other are modified, and c Dnsequently 
might not, indeed would not, behave exactly as the first 
had done. 

Wohler's synthesis could not be immediately employed 
for the preparation of substituted ureas, as at the time, 
and for more than twenty years afterward, the compound 
ammonias were unknown ; indeed, it is interesting to 
recall that it was from the compound ureas that the first 
substituted ammonias were prepared by Wurtz. 

Wurtz had synthesised methyl and ethyl cyanate, and 
tried, among other things, the action of a concentrated 
aqueous solution of ammonia upon them. By this treat- 
ment he obtained crystalline bodies which on investigation 
proved to be substituted ureas containing a methyl or an 
ethyl group in place of an atom of hydrogen. By heating 
these, which were solid substances easily isolated, with 
caustic potash, he obtained methylamlne and ethyl- 
amine, another very notable discovery. In a note pub- 
Jished fourteen years afterwards (Repertoire de Chimie 



Pure, 1862, iv., 199), Wurtz definitely states: — "It was 
in studying the decomposition of these ureas that I dis- 
covered the compound ammonias." 

Wurtz soon found that these and many similar primary 
amines could be formed directly by the action of potash on 
the cyanic esters. 

Having obtained the amines, Wurtz at once substituted 
them for ammonia in the Wohler synthesis," and thus 
obtained a whole series of substituted ureas. He states 
the case very clearly (Comptes Rendtis, 185 1, xxxii., 414) : 
— " The diff'erent terms of this series are formed, like urea 
itself, by the reciprocal action of the elements of cyanic 
acid and the elements of any ammoniacal base whatever. 
If, for example, one allows cyanic acid to react upon 
methylamine, there is formed a substance which stands in 
the same relation to ordinary urea that methylamine does 
to ammonia ; that is, it is urea in which an equivalent 
of hydrogen has been replaced by an equivalent of methyl. 
It is methyl urea. To prepare it, it is sufficient to evaporate 
to dryness a solution of equivalent quantities of sulphate of 
methylamine and of potassium cyanate, and to take up the 
residue by alcohol. The cyanate of methylamine which is 
formed by double decomposition undergoes by the action 
of heat a metamorphosis analogous to that which ammo- 
nium cyanate undergoes. It becomes transformed into a 
true urea, which only differs from ordinary urea by the 
elements of CH2." 

Wurtz had found that the action of ammonia on the 
cyanic esters which gave rise to the first substituted ureas 
was a general reaction, and continues : — " Nothing would 
be more easy thin to substitute for methylamine another 
ammonia, and to prepare by this method a series of bodies 
similar to urea in constitution and properties. It is more 
convenient, however, to obtain these bodies by another 
procedure which I indicated some years ago, and which 
consists in substituting for cyanic acid the cyanic ethers, 
and treating them directly with ammonia. Not only 
ordinary ammonia, but even the compound ammonias and 
certain soluble natural alkalis, react energetically with the 
cyanic ethers. The numerous compounds which one is 
thus able to obtain resemble urea closely in their more 
obvious characteristics ; thus they are neutral to litmus ; 
they combine more or less easily with nitric acid, and under 
the influence of potash they split up into carbonic acid and 
ammonia. ... I call them compound ureas, because 
they are to be looked upon as ordinary urea in which one 
or more equivalents of hydrogen are replaced by one or 
more complex molecular groups." 

In spite of various attempts, ammonium thiocyanate was 
not transformed into the sulphur analogue of urea until 
1869, when Emerson Reynolds (Trans. Chem. Soc, 1869, 
xxii., 2) showed that although, owing to the greater 
stability of ammonium thiocyanate, intramolecular re- 
arrangement did not take place at 100° C, it took place 
at temperatures above 180° C. With this synthesis of 
thiourea one important chapter in the history of the urea 
group was concluded. That much remains to be discovered, 
even regarding urea itself, is shown by the recent synthesis 
of its dichloro derivative. 



Substitution of Magnesium for Zinc in the 
Synthesis of Unsaturated Alcohols.— W. Jaworsky. — 
Magnesium can conveniently be used in place of zinc for 
the preparation of unsaturated alcohols by Saytzew's 
method under certain conditions. The reaction is per- 
formed in one phase, without previous preparation of the 
organo-metallic compound, and takes place in absolute 
ether. The mixture of allyl haloid and carbonyl com- 
pound must be added drop by drop at a rate regulated by 
the energy of the reaction, and the mixture may be dis- 
solved in ether if the reaction is very rapid. — Berichte, 
xlii.. No. 2. 

* Hofmann had somewhat earlier (^n«., 1845, •'•»•> 57.! *°<* '846, 
Ivii., 265) prepared phenyl urea by the interaction of aniline sulphate 
and potassium cyanate. 



124 



Simple Notation for indicating Configuration of Sugars, &c. i^MaKh*!";.^"^'' 



A CONTINUOUS APPARATUS FOR EXTRACTING 
SOLIDS. 

By NORMAN L. GEBHARD and F. BRYAN THOMPSON. 

The apparatus is arranged as in the figure. The extracting 
liquid is placed in the Erlenmeyer Hask a, which is fitted 
with a two-holed cork. On boiling the liquid, hot vapours 
pass up the tube b, and hence into the wide tube d, which 
contains the substance to be extracted. The solid itself is 
kept in position in d by means of a small perforated porce- 
lain disc held in the constricted part of the tube, and the 



fr^ 



s s^ 




hot vapours in passing through d thoroughly extract the 
substance which it contains, and are then condensed in the 
double surfaced condenser e, and thence return to the 
flask. For safety purposes a small side arm, g, open to 
the air, is fused into the adapter f, and thus prevents the 
generation of pressure in the apparatus. If the positions 
of D and E are interchanged, the solid in d can then be ex- 
tracted by percolation by the cold liquid condensed in e. 
The whole is very simple, and has been found extremely 
useful in many cases. 
Chemical Laboratory, 
The Technical College, Derby, 



A SIMPLE NOTATION FOR INDICATING 

THE CONFIGURATION OF THE SUGARS AND 

ALLIED SUBSTANCES. 

By T. S. PATTERSON. 

It is common knowledge that for the purpose of indicating 
the configuration of substances belonging to the sugar 
group, Emil Fischer has suggested the use of the signs + 
and — to represent the position of the - OH groups 
in a given molecule ; thus, (f-glucose = hexapentolal 

H H+ ; <i-saccharic acid = hexantetroldiacid + — + + 

(or 4- — ) ; £?-fructose = hexanpentol-2-on — + + , 

&c. (E. Fischer, Ber., 1894, xxvii., 3222) ; and that an 
attempt has been made by Lespieau {Bull. Soc. Chim., 
1895, [3], xiii., 105), and another by Maquenne (" Les 
Sucres et leur Principaux Derives," Paris, 1900), to intro- 
duce an even more comprehensive nomenclature. None 
of these methods, however, is of very great assistance to 
the memory. The two latter fail, perhaps, on account of 
their very comprehensiveness, and the first is not fully 
satisfactory, possibly because our minds are not trained 
to memorise a sequence of + and - signs. We have, 
however, become accustomed to register the positions of 
radicles by associating them with a sequence of letters or 
of figures, and in the following suggestion an attempt is 
made to translate, in as simple a way as possible, 
Emil Fischer's method into figures, somewhat after the 
manner of Lespieau and Maquenne. For this purpose the 
following conventions, which for the most part are already 
in use, are adopted. 

1. The empirical names of the compounds under con- 
sideration are retained.* The present scheme makes no 
attempt, therefore, to indicate the chemical constitution of 
a given compound, and it thus remains necessary to 
remember, e.g., that arabinose and lyxose are aldehydes 
with a chain of five carbon atoms ; that erythulose, 
fructose, sorbose, tagatose are ketones ; that dulcite is 
entirely an alcohol ; that mucic acid is a dibasic acid, 
and so on. 

2. It is clear that it is only necessary to remember the 
configuration of one of any pair of antimeres. We may 
therefore fix our attention on the d-compounds. 

3. Writing, e.g., the formula for d-arabinose in Emil 
Fischer's manner, it is obviously only necessary to consider 
the distribution of the H - and — OH groups on one side of 
the formula. We may therefore select the right-hand side. 

CHO 



HO- 
H- 
H- 



(3) 



(2) 



(I) 



-H 



-OH 



-OH 



CH2OH 

4. Since only two radicals, H- and -OH, come into 
consideration, we need only take account of one of these, 
and, following Emil Fischer, we choose the —OH groups. 

5. If, then, the most highly oxidised end of the chain is 
always placed uppermost, the configuration of a compound 
may be accurately defined if we indicate by a symbol the 



* The reason for so doing has been expressed by Emil Fischer {Ber., 
1907, xl., 103) as follows : — " Meine erwartung das diese rationellen 
Namen bald die alten empirischen Ausdriicke in den Hintergrund 
drangen wiirden, ist aber nicht eingetroffen. Im Gegenteil, fiir neu 
entdeckte Zucker mit geringerem Kohlenstoffgehalt sind seitdem 
immer noch empirische Namen gewahlt worden, und ich ziehe daraua 
den Schluss, dass diese der Mehrzahl der Fachgenossen sympathischer 
sind, als die rationellen Ausdriicke, die man sich zum Verstandniss 
immer erst in die konfigurationsformel iibersetzen muss." 



Chemical News, 

March 12, 1909 



Simple Notation for indicating Configuration of Sugars, &c, 1 25 



Butane derivatives. 



Table I. 
Pentane derivatives. 



rf-Malic acid 
(i-Erythulose 
i-Erythrite. . 
i-Tartaric acid 
rf-Erythrose . . . I / 
d-Erythronic acid ) ^ 



••!(o)(i 



rf-Lyxose 1 , > 

rf-Lyxonic acid . . . . M ^ 
rf-Trioxyglutaric acid . | / , , . 

rf-Arabite \W\^-2) 

rf-Arabinose I / > 

d-Arabonic acid . . . . P^ ' ^' 



rf-Erythrite . 
(/-Tartaric acid 
d-Threose . . 
rf-Threonic acid ., 



(2) 



(2) 



3) 



rf-Xylose • . 
(f-Xylonic acid . . 
Xylotrioxyglutaricacid • , > / 

Xylite \^^'^^ 

'^-Ribose I, , 

rf-Ribonic acid . . . . I ^^ * ^ * J' 
Ribotrioxyglutaric acid 
Adonite ... 



Hexane derivatives, (a) 

Dulcite, mucic acid (1.4), (2. ) 

^-Galactose (i • 4) 

rf-Tagatose (i) 

<f-Talose (i) 

rf-Talite, d-talomucic acid .. .. (i), (1.2.3) 
d-Mannite, d-mannosaccharic acid (i . 2) 

rf-Mannose (i • 2) 

rf-Fructose (i • 2) 

rf-Glucose (1.2.4) 

d-Sorbite, cf-saccharic acid . . . . (i . 2 . 4) (2) 

£?-Sorbose (2) 

(f-Gulose . . (2) 

rfldite, </-idosaccharic acid .. ..(2.4) 

rf-Idose (2.4) 

Allomucic acid (i . 2 . 3 . 4) (o) 



1(1-2.3) (o) 



(a) In order to save space, the monobasic hexonic acids are omitted in this column. 

II. 

rf-Fructose (i . 2) — > (/-mannite (i . 2) —> rf-mannose (i . 2) — > rf-mannosaccharic acid (i . 2) 

t 

«-Sorbl« j- - 4) :^ ^-llu-M. . - 4) :J ,,„eha,ic acid (' • - 4) 

(J-Sorbose (2) ->■ rf-idite {2 . 4) — > tf-idose (2 . 4) — >■ <j-idosaccharic acid (2 . 4) 

D".ci.e (- 4j :> ^iSs? ('2 /i' Z -- -« % : i 



position of the —OH groups on the right-hand side of the 
formula. To do this we may number the asymmetric 
carbon atoms from below upwards (see further on), as 
shown above, and including such carbon atoms as may 
become asymmetrical.* 

Thus, on the right-hand side of the above formula 
or c?-arabinose a hydroxyl group is found on the first 
asymmetric carbon atom, and another on the second, 
whilst the third is on the left-hand side. 

Therefore we may write d-arabinose (i . 2) as a symbol 
representing the configuration of the substance. 

Similarly, we shall have rf-lyxose (i), rf-xylose (2), and 
rf-ribose (1.2.3), whilst the symbols for the antimers would 
be /-arabinose (3), /-lyxose (2 . 3), /-xylose (i . 3). 

In /-ribose, — 

CHO 



HO H 

HO H 

HO H 

CH2OH 

there is no hydroxyl group on the right-hand side of the 
formula. I suggest for this the notation /-ribose (o). 

For substances having the same group at each end of 
the molecule like adonite, mannite, or the dibasic acids, 
there are usually two different symbols possible, just as in 



♦ For instance, on reduction of— 

(4) (3) (2) (I) 

CH2OH.CH.OH.CO.CH.OH.CHOH.CH2OH, 

the carbon atom (3) of the CO group would become asyraraetrical, and 
must therefore be taken account of, 



Emil Fischer's nomenclature d-saccharic acid like d-sorbite 
has two symbols, -\ 1-+ or \- — . For these com- 
pounds I propose to write d-sorbite'^ '/,"^', ^/-saccharic 

acid (^ • 2 • 4) 
acid ^2) • 

d-Idosaccharic acid (2 . 4) has only one symbol, or rather 
its two symbols happen to be identical, whilst, as repre- 
senting the inactive compounds of this class, we have, e.g., 

dulcite r "*(, allomucic acid ^^ ' / 'x^ ' '^'. 
(2.3) (o) 

In this connection it is of some importance to notice 
that for such compounds of this class as are active, the 
same figure (or figures) occurs in both symbols. Thus, in 

rf-sorbite '^ '/^Z ^' the figure 2 in the second symbol 

occurs also in the first (1.2. 4), and similarly for </-idite 

\' y both figures of the second symbol occur in the first 

symbol. For inactive substances, on the other hand, the 
second symbol is entirely different from the first, as in dulcite 

y ' M, or allomucic acid \^ • 2 • 3 • 4)_ 
(2.3) (o) 

In Table I. are given the numerical symbols for a 
group. It will be seen from this list that the relationship 
between the derivatives of butane, pentane, and hexane is 
considerable number of compounds belonging to this 
exhibited very clearly by the numerical symbols, as, for 
instance, in comparing (/-erythrose(i . 2), rf-arabinose(i . 2), 
d-mannose (i . 2), and (f-fructose (i . 2), but such relation- 
ships can only be brought out when the numbering of the 
asymmetric carbon atoms is from below upwards, and this 
is the reason for the adoption of that convention, the only 
one which is opposed — and then only slightly — to the sug- 
gestions of Emil Fischer. 

That the relationships amongst these compounds is as 
clear from the numerical symbols as from the graphic 
formulae will be seen from the following illustrations ;^» 



126 



Influence of Moisture on Chemical Change. 



(a) <^-Arabinose (i . 2) by the cyanhydrine reaction must 

yield two compounds having the symbols (1-2) and 
(1.2. 4). The former is <2-mannose (i . 2) and the 
latter <f -glucose (1.2.4). 

(b) The connection between d-sorbite and the hexoses 

derived from it is very plainly shown thus : — 

(2) — > |d-gulose (2 

J c-..u:»«. — ^ rf-mannose (i . 2) 

rf-Soibite (1.2.4) 



4). 



<f-glucose (i . 2 
rf-idose (2 . 4) 

(c) The interconversion of the various members of the 
group can readily be followed (see II.). 

The advantages of the system suggested above thus 
appear to be : — 

1. The configurations of the compounds of the sugar 
group can be represented clearly by a simple numerical 
notation. 

2. This allows of easy representation of the relationships 
and transformations of the compounds with great saving 
of space. 

3. It is easily possible by very short study to memorise 
the numerical symbols, and, in consequence, the configura- 
tions of the substances in question. 

4. The system is very useful for teaching purposes. 
The University, Glasgow. 



THE INFLUENCE OF MOISTURE ON CHEMICAL 

CHANGE.' 

By Dr. H. BRERETON BAKER, M.A., F.R.S. 

The influence of a trace of water vapour on a chemical re- 
action was first noticed by Prof. H. B. Dixon in i88o. He 
found that it was possible to pass electric sparks in a mix- 
ture of carbon monoxide and oxygen without explosion, if the 
mixture had been very carefully dried. Shortly afterwards 
Cowper proved that dried chlorine had little or no action 
on several metals. Further observations were made by 
Prof. Dixon's pupils, the author in 1884 showing that 
carbon could be heated red-hot in dried oxygen, that 
sulphur and even the very inflammable phosphorus could 
be distilled in the same gas without burning. Later 
experiments proved that ammonia and hydrogen chloride 
gases could be mixed without uniting, and that the readily 
dissociated ammonium chloride could be converted into a 
true vapour, and that sulphur dioxide could be crystallised 
on lime, provided always that moisture was, as far as 
possible, removed. In 1902 it was shown that tubes con- 
taining very dry and pure hydrogen and oxygen could be 
heated to redness without any explosion resulting, and in 
1907 that nitrogen trioxide could exist in the gaseous state 
if carefully dried. 

Taken altogether, some twenty-five simple chemical 
actions have been shown to be dependent on the presence 
of moisture, and two only, the burning of cyanogen and 
carbon bisulpide, seem to take place as easily when dried 
as when moist. In 1893 Sir J. J. Thomson showed that a 
potential difference of 1200 volts was unable to cause the 
passage of electric sparks through very dry hydrogen, and 
in the same year the author was able to stop the passage 
of the discharge from an induction coil by carefully drying 
the gas between the platinum points. 

The amount of water necessary for the bringing about of 
chemical action is extremely small, less in all probability 
than one part in three hundred thousand of the reacting 
gases. Many hypotheses have been suggested for the 
explanation of its action. Prof. Dixon believed in the case 
of carbon monoxide and oxygen, that the water vapour 
acted as a carrier of oxygen by alternate reduction and re- 
Qxidation of the hydrogen. Traube imagined an alternate 



• Abstract of the Wilde Lecture, delivered before the Manch 
Literary and Philosophical Society, March gth, 1909. 



t Chemical Nbws, 
I March 12, 1909 

formation and decomposition of hydrogen peroxide. Dr. 
Armstrong in 1884 suggested a theory of "reversed 
electrolysis," the impurity of the water vapour rendering it a 
conductor. Sir J. J. Thomson in 1893 published a paper 
showing that if the forces holding the atoms of a molecule 
together were electrical in their nature, these forces would 
be very much weakened in presence of liquid drops of any 
substance of high specific inductive capacity such as 
water. 

In 1895 it was shown that the newly discovered Rontgen 
rays were able to cause a gas to become a conductor of 
electricity, and it was thought at that time that the 
molecules of the gas were split up into atoms by this 
agency. If this were so, it seemed likely that under these 
circumstances chemical action would take place in absence 
of water, but a joint paper of Prof. Dixon and the author, 
in 1896, showed that the Rontgen rays, at the ordinary 
temperature, had no measurable effect on the commbina- 
tion of dried gases. Since that time, however, the re- 
searches of J. J. Thomson, Rutherford, Townsend, and 
others have proved that the ionisation of gases is of a dif- 
ferent character. The negative ions are extremely small 
particles of the mass of about i/ioooth part of the mass of 
an atom of hydrogen, the positive ion being the residue, 
but whether it is the residue of a molecule or of an atom 
seems to be still doubtful. 

With the view of illustrating the influence of ionisation of 
gases on chemical change the author devised a new experi- 
ment. It is known that mercury vapour, under ordinary 
circumstances, contains only atomsof mercury which exhibit 
little tendency to combine with oxygen. The vapour, 
however, is ionised in the mercury vapour lamp, and when 
the current is cut off and oxygen is admitted shortly after- 
wards, the mercury becomes covered with a layer of 
mercuric oxide. Since the temperature of the lamp is 
much below that at which ordinary mercury vapour com- 
bines with oxygen, it is evident that in this case ionisation 
can bring about chemical action. 

It is probable that this ionisation of mercury is different 
from the ordinary ionisation of gases. It may be regarded 
as the splitting off of an electron from the atom as distinct 
from a molecule, and the charged atom of mercury can 
then enter into union with oxygen. The two cases men- 
tioned above of combustions in oxygen which are apparently 
unaffected by the absence of moisture, those of carbon 
bisulphide and cyanogen, are perhaps to be explained in 
the same way. Both gases are readily broken up into 
their elements, and it has been shown that carbon bisul- 
phide breaks up at a lower temperature than that required 
for its burning. When these gases are heated, charged 
atoms are probably formed, capable of direct union with 
oxygen. 

To test further the question as to whether the ionisation 
of molecules, as distinct from atoms, as in the case of 
mercury vapour, can bring about chemical change, some 
recent experiments were described in which radium bromide 
was used as the ionising agent. Small quantities of this 
salt contained in open silica tubes were sealed up in tubes 
containing mixtures of hydrogen and oxygen and carbon 
monoxide and oxygen, the gases being very dry in some 
cases and moist in others. In no case was any chemical 
action observed, although the tubes were allowed to stand 
at 20° for over two months. By means of a vacuum guage 
the combination of 1/10,000 of the whole could have been 
detected. Another experiment showed that radium bromide 
was able to produce ionisation in very dry air, so that the 
want of chemical action in the above experiments must 
have been due to the fact that ionisation cannot of itself 
produce chemical action. Ihere remained, however, the 
possibility of ionisation increasing the rate of union of two 
gases which were otherwise under conditions which would 
produce a slow chemical action between them. The re- 
action between nitrous oxide and hydrogen was found to 
be a suitable one for investigation, since it takes place 
slowly and uniformly at 530°. It is known that many sub- 
stances when heated ionise gases. Lime is fairly effective 



Chemical News, I 
March 12, 1909 f 



Chemically Treated Flours. 



127 



'n this respect, thoria to a much greater extent, and radium 
bromide is the most effective of all. Accordingly tubes 
containing the mixture of not very dry hydrogen and 
nitrous oxide were prepared. One contained a little lime, 
a second some thoria, and a third some radium bromide. 
These tubes were heated in an electric resistance furnace 
side by side with comparative tubes containing the same 
gases in which was a small quantity of powdered Jena 
glass to make the conditions as similar as possible. It 
was found that the rate of combination was much quickened 
by the presence of lime, much more by the presence of 
thoria, while the gases in contact with radium bromide, 
directly the combining temperature was reached, combined 
with explosion. 

When a tube containing thoria and the same mixture 
was dried for ten days by phosphorus pentoxide, the gases 
showed no measurable combination when heated for five 
minutes to 530°. Hence increasing the ionisation in 
presence of moisture increases the rate of chemical change, 
while in absence of moisture it apparently has no effect. 

An experiment of rather different type was shown which 
illustrates the way in which the ionisation of gases may 
exert its influence. A mixture of sulphur dioxide and 
sulphuretted hydrogen can be kept unchanged, although 
water vapour is present in some quantity. If, however, 
liquid water is introduced, separation of sulphur is im- 
mediate. A small open tube of radium bromide was placed 
in such a mixture, and after standing some time the whole 
of the gases condensed in the small tube of radium bromide 
in the form of sulphur and water. There is little doubt as 
to what happens in this case, the water vapour condenses 
in liquid drops on the ionised particles in the radium tube, 
and in these drops the reaction between the two gases is 
completed. In the other chemical changes at high tem- 
peratures it is conceivable that condensation to some form 
approaching the liquid state might take place, in which 
case Sir J. J. Thomson's theory would apply. 

In support of this view must be mentioned some very 
recent experiments of Prof. J. S. Townsend, which show 
that a very great diminution in mobility of negative ions is 
produced when a mere trace of water vapour is added to a 
dried gas ionised by Rontgen rays. If there is any truth 
in this provisional working hypothesis, it should be found 
that ions and water vapour (or some similar substance) 
must both be present in a mixture of gases if action is to 
take place. Experiments already in progress seem to 
show that this is the case, but they have not been suffi- 
ciently often repeated for it to be desirable to publish the 
results at this stage. 

The lecture was illustrated by experiments showing the 
influence of small quantities of moisture on chemical 
actions. 

(Note. — The author finds that liquid water invariably 
collects in tubes containing salts of radium, though these 
salts are not at all deliquescent. In one experiment 
10 mgrms. of radium bromide increased in weight by 
1-5 mgrm. when allowed to stand for two days in an 
atmosphere saturated with moisture at o" C). 



CHEMICALLY TREATED FLOURS.* 

By E. F. LADD, Food Commissioner and Chemist. 

(Continued from p. 112). 

Pancreatic Digestion. — The next problem was to investi- 
gate the action of pancreatic digestion on the three different 
products. The pancreatic solution was prepared for this 
work according to the directions given by Simons, which 
are as follows : — 

To 100 cc. of water 0-28 grm. of pancreatin and 1-15 
grms. of NaHCOs were added. Two hundred cc. of this 
solution was used in each experiment. 

* Special Bulletin from the Government Agricultural Experiment 
Station, Agricultural College, N.D., December, 1908. 



Four experiments of pancreatic digestion were made, 
using in each case the raw gluten obtained from 10 grms. 
of flour. The following results were obtained :— 

Pancreatic digestion of raw gluten from commercially 
bleached flour : — 



No. of tube. 


T 


me of digestion 






Hrs. 


Mins. 


I. 




3 





2. 




3 


30 


3- 




3 


15 


4- 




3 






The following results were obtained for the unbleached 
flour : — 

Time of digestion. . . 

No. of tube. Hrs. Mins. 

1. r 30 

2. 20 

3- I 45 

4. 20 

5. 20 

It will be noted that in the case of the bleached flour 
three hours or more were required for the complete diges- 
tion, while the unbleached digested in two hours or less. 

Several tests of each case were made with baked gluten, 
but the difference, however, could not be so well established 
as the rate of digestion was so rapid that the difference n 
time was not as marked as with raw gluten. 

Baked Gluten from Commercially Bleached Flour, 

Time of digestion. 
No. of tube. Hrs. Mins. 

1. o 45 

2. ID 

3- o 45 

Baked Gluten from Unbleached Flour. 

Time of digestion. 
No. of tube. Hrs. Mins. 

1. o 30 

2. O 45 

3- o 45 

It will be noted that in every experiment in both cases 
the gluten digested in one hour or less. 

The bread from bleached and unbleached flour was ntxi 
tried with the following results : — 



Bread from Bleached Flour. 


No. of tube. 


Time of digestion. 
Hrs. Mins. 


I. 


I 


45 


2. 


I 


45 


3- 


2 





4- 


2 





5- 


2 





Bread from 


Unbleached Flour. 


"io. of tube. 


Time of digestion. 
Hrs. Mins. 


I. 


I 


15 


2. 


I 





3- 


I 





4- 


I 





5- 


I 


30 



By accident a much better test of digestion for the bread 
was discovered ; that of digestion by means of the ordinary ' 
mould. Some of the bread used in the preceding experi- 
ments was allowed to stand in sealed Mason jars, and it 
was noticed that a large formation of mould appeared on 
the bread from unbleached flour in four days, while that 
from the commercially bleached flour remained free from 
any appreciable amount of mould for nearly ten days. 
However, the jars containing these samples of bread were 
not sterilised, and it was thought that this formation of 
mould might possibly be due to different conditions existing 
in the different jars. To determine this point the following 
experiments were carried out, in which we tried to make 
the conditions about the same. 



128 



Chemically Treated Flours. 



(Chbmical News, 
March 12, 1909 



Jars were sterilised in the hot-air oven at 115° C. and 
used in experiments which were carried out as follows : — 

Firsi Jar. — Bread made from unbleached flour was 
inoculated with some of the mould on the unbleached bread 
used in the above experiment. 

Second Jar. — Bread made from bleached flour was in- 
troduced and inoculated with some of the same mould 
used in No. i. 

Third yar. — Bread made from unbleached flour was 
introduced and inoculated with some of the mould on the 
bleached bread used in the former experiment. 

Fourth yar. — Bread made from bleached flour was in- 
troduced and inoculated with the same mould as in No. 3. 

The reasons for making these two distinct tests in 
carrying out these experiments with the mould was due to 
the appearance of the mould on the bleached bread, as it 
seemed to be of a more destructive nature and it was 
thought that possibly it might be that it was of a diff"erent 
character. The results from the above experiments were 
as follows : — 

The bread from the unbleached flour, in both cases, 
stood in the jars tightly sealed for two days before the 
mould made any appreciable show. The bread, however, 
from the commercially bleached flour, in both cases, re- 
sisted the action of the mould for five days. 

The samples, however, were allowed to stand for ten 
days and further development noticed. The bread made 
from unbleached flour, at the end of this time, was almost 
entirely eaten up, while that from the bleached flour was 
well covered with the mould, but the texture remained 
good. 

The tests with the mould indicate the same general 
conclusions as those brought out by the pepsin and pan- 
creatic digestions, as it shows that the mould digests the 
bread with a marked difference. 

The point might be raised that bleaching was a good 
thing as it acted as a preservative for the bread, but the 
pure food law wisely does not allow preservatives of other 
character, such as sulphites in meats, to be used, and 
this, no doubt, is similar in character so far as its effect is 
concerned. 

The point was now brought up, if the nitric oxide acted 
upon the flour, what portions did it act upon — the starch, 
the gluten, or only on the fat ? To determine this point 
the following observations were made : — 

If the nitric oxide acted upon the starch it would, no 
doubt, form a very low nitrated nitro-starch product, and 
if this were the case, when treated with an acid, and 
heated up, would give off nitric oxide that would act upon 
starch, iodide paper, or a solution of starch and potassium 
iodide ; but when 100 grms. of flour were treated in this 
manner, no such reaction was observed, showing, without 
doubt, that there could not be any action on the starch. 
However, it was noticed that a large amount of gas was 
given off, more than could be accounted for by being dis- 
solved in the acid solution or by the expansion of the small 
amount of air left in the flask. This phenomenon was not 
noticed when unbleached flour was used. 

The next problem now was to determine what this gas 
was, and as we had no action in the starch it remained 
either to be a decomposition product from fat or gluten. 

A 50 grms. sample of bleached flour was then taken and 
the fat extracted. This fat was then treated in the same 
manner as the flour, but no such action was noticed ; thus 
it could only be caused from an action on the gluten, but 
what this action was remained to be determined. 

In studying over the reactions which might occur be- 
tween such bodies as the protein bodies and nitric oxide, 
we will readily see the possibility of a diazo reaction, and 
if this occurred the gas should be nitrogen. A Schiff's 
azotometer was fixed up to collect such gas, and 100 grms. 
of flour was treated in the manner described above. After 
the complete apparatus had been filled with CO2 to drive 
out all the air, then the acid, which had been previously 
boiled and was still warm, was introduced through a sepa- 
rating funnel, and the gases forn^ed driven over into the 



azotometer by more CO2 (the CO2 being absorbed by the 
KOH in the azotometer), the nitrogen collecting in the top 
over the KOH. A very small amount of the nitrogen was 
given off, but enough to be readily measured. This, how- 
ever, if carried farther, would, no doubt, give means of 
determining the amount of NO2 that actually went into the 
chemical combination ; and, if the flour was over-bleached, 
the excess could then be approximately determined. 

Further evidence to prove this point has recently been 
secured. In bleaching some flour to the limit to try to 
duplicate that which collects on the agitators and in other 
parts of the bleacher, it was also noticed that quite an 
appreciable heat was developed, indicating, no doubt, that 
a definite chemical reaction was going on. The flour also 
absorbed the first volume of nitric oxide with extreme 
readiness. Further, it was noticed that there was a point 
that this readiness of absorption by the flour was at an end, 
and in order to make the flour further take up more of the 
gas vigorous shaking was required, and the stream of gas 
had to be diminished. 

This would seem to indicate that the gas acted on the 
gluten or some part of the gluten until its affinity for the 
gas was satisfied, and the further action was either a 
secondary action on the gluten or that a low nitrated 
nitro-starch was formed, which point is now under in- 
vestigation. 

The next work relating to this subject was done in the 
bleaching of different flours. A first patent durum flour 
was bleached with varying amounts of the nitric oxide 
under the same conditions, using 5 cc, 10 cc, &c., to the 
100 grms. of flour. The one bleached with 20 cc, how- 
ever, was slightly over-bleached. This blended with the 
best white hard wheat flour was used for a standard. The 
following mixture being made : — 

Blended Standard Remarks, 

(percent). (percent). 

10 90 \ 

^° g° I Could not be detected by slick. 

30 70 j 

It is evident that by the ordinary tests that 30 per cent 

of durum could be introduced without detection. The 

same thing was tried with flour which was bleached, with 

10 cc. NO2 to 100 grms., with practically the same results. 

Conclusions, 
As the result of the experiments already given in the 
preceding pages, and in previous articles, we may sum-" 
marise the facts in the following conclusions :— 

I. That nitrous and nitric acid are two of the con- 
stituents formed from the bleaching of flour with nitrogen 
peroxide. . 

II. The nitrites and nitrates, or nitrite and nitrate re- 
acting material, are among the products formed in the 
flour. 

III. That bread as baked in the home by the domestic 
method will contain from one-third to one-half of the 
nitrite reacting material found in the flour. 

IV. Oil properly extracted and purified from unbleached 
patent flour contains no nitrogen. 

V. Oil extracted from bleached flour and purified by 
the same methods gives a strong reaction for nitrogen, thus 
confirming the statement made by Lewkowitsch. 

VI. Oils from unbleached flours have an iodine absorp- 
tion number (Hanus' method) of loi or more, while the 
iodine absorption number for oils from bleached flours, 
when properly purified, will have a lower iodine number in 
proportion to the amount of bleaching. 

VII. The difference in the iodine number and the dif- 
ference in the nitrogen content of the oils show that the 
bleaching agent has acted upon the fat of the flour. 

VIII. Flours aged for nine months showed no reduction 
in iodine number, while the same flour bleached and aged 
for the same length of time showed a reduction of 17 i-io 
points, indicating that the artificial bleaching is not the 
ss^ine as the natural ageing of flours. 



Chemical News, I 
March 12, 1909 I 



Institute of Chemistry. — Annual General Meeting. 



129 



IX. The proportion of nitrates in the bread increases as 
as the nitrites decrease. 

X. The method of baking will determine to what extent 
the nitrites are changed or eliminated in the bread. 

XI. Artificial digestion experiments with pepsin solu- 
tions show that the gluten from the unbleached flour was 
digested in four hours and fifty-seven minutes ; while, 
under the same conditions, the gluten from the bleached 
flour was digested in eight hours and forty minutes. 

XII. The baked gluten from the bleached and unbleached 
flours showed similar variations but not so wide, the time 
of digestion being much less ; the same is true for the bread 
made from such flours. 

XIII. In pancreatic digestion the glutens digested in 
3*19 hours from bleached flour, and in 2-31 hours from 
unbleached flour. The time of digestion in pancreatic 
solutions of the baked gluten and of the bread was in 
favour of the unbleached product. 

XIV. The experiments made with the keeping quality of 
bread made from bleached and unbleached flour demon- 
strated the antiseptic effect of the bleaching agent. 

XV. It has been demonstrated that when the diazo or 
like action took place, the acid acted upon the gluten of 
the flour, changing its composition so that nitrogen gas was 
given off when the flour was treated with an acid. 

XVI. The fact that the xanthoproteic reaction takes 
place demonstrates further that the bleaching agent has 
acted upon the gluten or the protein of the flour. 

(To be continued). 



PROCEEDINGS OF SOCIETIES. 

THE INSTITUTE OF CHEMISTRY. 
Annual General Meeting, March ist, 1909. 

Professor Percy F. Frankland, the retiring President, 
in the Chair. 

On the motion of Mr. A. Gordon Salamon, Hon. 
Treasurer, seconded by Mr. Arthur C. Claudet, the 
Financial Statement for 1908 was received, and a vote of 
thanks accorded to the Hon. Auditors. 

Mr. Salamon said that, regarded as a business concern, 
the position of the Institute was sound for its present 
needs ; it was paying its way and putting a little by, but 
it had not sufficient to meet the problem of the future, 
namely, the approaching expiry of the lease of its 
premises. During the year 1908, however, the improve- 
ment in the finances of the Institute had been more than 
fully maintained. 

The President then submitted the Report of the 
Council, directing the attention of the Fellows and Asso- 
ciates to the principal items in the work of the Institute, to 
which he referred in more detail subsequently in his 
Address. 

Dr. Frank Clowes, in seconding, said that he had 
attended many Annual Meetings, and it was a great 
pleasure to him to hear of the continued progress of the 
Institute in all its work and in new work. When he was 
a teacher, he always advised his students to work for 
the qualification of the Institute, and now that he was 
engaged as a professional chemist he was glad to see that 
the authorities of the London County Council fully recog- 
nised the value of A.I.C. and F.I.C. 

The Report was received and adopted. 

Prof. Percy F. Frankland, the retiring President, then 
delivered his Address. Whilst he regretted that the honour 
of representing the Institute had drawn to a close, it was 
by no means disagreeable to leave the responsibilities 
which the office of President involved. He was very 
thankful that through good fortune and the help of the 
Council and officers with whom he had been associated he 
was able to band over the affairs of the Institute in as 



sound and healthy a condition as when he took them over 
from his predecessor three years ago. The roll of the 
Institute had increased by seventy-eight Fellows, thirty 
Associates, and sixty-eight Students ; and notwithstanding 
the increasing stringency of the regulations, the number 
of candidates for examination had increased from ninety- 
four (in 1906) to one hundred and fifty (1909). He believed 
these figures indicated that a real advance was taking 
place in the demand for highly trained chemists. He 
would emphasise the fact that whilst the well-being of the 
community was greatly promoted by the services of com- 
petent chemists, the mischief which could be wrought by 
the ill-trained and incompetent was incalculable. It was 
one of the chief duties of the Institute to maintain a high 
level of training for professional chemists by demanding 
of candidates for its membership evidence of thorough 
training, and by requiring them to pass searching examina- 
tions. Particular attention had lately been given to the 
educational side of the Institute's activity, and he referred 
to five important changes. Latin, hitherto compulsory, 
had been transferred to the list of optional subjects in the 
Preliminary Examination ; the number of Examiners had 
been greatly increased, forming a Board the members 01 
which were jointly responsible for the Examinations ; 
written papers had been introduced in the Final Examina- 
tions ; a working knowledge of French and German would 
shortly be required of all candidates for the Final Exami- 
nation ; and the Council now encouraged the holding ot 
Examinations in India, in the Colonies, and in different 
centres of the United Kingdom. There was no finality 
either in the syllabus of the Examinations or in the courses 
of training demanded ; such arrangements would require 
frequent remodelling in the future as the development of 
science and improvement of facilities of higher training 
might dictate and render possible. 

The President then referred to the criticism of the 
Institute by Prof. Kipping in his Presidential Address to 
the Chemical Section of the British Association at the 
meeting last year, wherein he indicated that the Institute 
ignored the necessity of research work, and suggested that 
good research work should be insisted on in the case of all 
candidates for its Fellowship. 

Professor Frankland reminded the Fellows that the 
results of research were not necessarily recorded in the 
Transactions or Proceedings of the Royal Society, or in 
the pages of any scientific journal ; those were mostly for 
academic researches. There was a vast amount of re- 
search involving originality and attainments of the highest 
order which from its very nature could not be published at 
all. Should chemists who are engaged on such research 
be debarred from the Fellowship because their names are 
not at the head of so many dozen pages apiece of the 
yournal of the Chemical Society or in a similar publication ? 
He would assure Dr. Kipping that he had met chemists 
whose names are not associated with such academic re- 
searches who were nevertheless fully equipped and highly 
original investigators. Should these men not have been 
admitted to the Fellowship of the Institute ? Succeeding 
Councils had built up an organisation of real flesh and 
blood, and not a paper Utopia. Could anybody deny that 
the Institute had by its policy during the thirty-two years 
of its existence enormously improved the theoretical and 
practical equipment of professional chemists in this country, 
and that it had stimulated hundreds to pursue courses ot 
study which but for the Institute would never have been 
undertaken at all ? Could it be denied that the examina- 
tions were specially distinguished as tests of original 
capacity as well as of theoretical attainments, manipulative 
skill, and knowledge of routine methods ? Moreover, the 
Examiners were empowered to take into consideration any 
research work which any candidate might previously have 
carried out. He would yield to none in the advocacy ot 
research as a part of training, but one must not be misled 
by an empty phrase or mere nomenclature. There was 
much training in originality of thought and experimental 
procedure which was not called research, and much of 



130 



Studies on Malting. 



{Chemical News, 
March iz, igog 



what was called research that involved no originality in 
the thought or deed. 

The President then referred to the work of the various 
Committees, indicating how the Institute had endeavoured 
to promote the interests of its members. He made special 
reference to protests made by the Council against pro- 
fessional chemists being invited to apply for appointments 
by tender, and appealed to the Fellows and Associates to 
assist in the endeavour to crush this sinister development. 
The Institute had lately taken steps to establish an 
Appointipents Register, and had already succeeded in 
placing a number of members in good positions ; steps 
would be taken to make manufacturers and other employers 
aware of the existence of this register, which promised to 
be most useful. 

Passing to the most important item in his Address, the 
President intimated that a Special Committee had been 
discussing the arrangements to be made in view of the 
approaching expiry of the lease of the present premises of 
the Institute. The Committee had come to the conclusion 
that between ten and fifteen thousand pounds would have 
to be raised by voluntary contributions, in order to provide 
even a modest but dignified home in which the Institute 
could carry on its administrative work and conduct its 
examinations. They did not require a pretentious exterior 
or luxurious interior, but they wanted more commodious 
laboratories, offices, and library. The sum named left no 
margin for extravagance. The Committee had prepared a 
pamphlet setting forth the work of the Institute, discussing 
its present and prospective financial position, and giving a 
clear account of the aims in view, and the President urged 
the Fellows and Associates to read it carefully, after which 
they would, he felt sure, make such contributions as they 
could afford. Their joint action and personal sacrifice 
would continue to bear fruit in the time which is to come, 
long after they had become sleeping and forgotten members 
of that professional brotherhood in which it was their 
privilege now to be active workers. 

After congratulating the Institute on the choice of Dr. 
George Beilby, F.R.S., as the new President, Prof. 
Frankland thanked the Fellows and Associates for their 
kindness and consideration during his term of office, 
remarking that such service as he had been able to give to 
the Institute had been rendered a labour so pleasant as 
hardly to partake of the nature of toil. 

On behalf of the Fellows and Associates, the President 
then presented an Illuminated Address to Mr. David 
Howard, in recognition of his services to the Institute in 
various capacities, as member of Council, Honorary 
Treasurer (eighteen years), President, Vice-President, and 
Censor, extending altogether over thirty years ; at the same 
time congratulating him on the approach of his seventieth 
birthday, while yet retaining remarkably his health and 
vigour. 

Mr. David Howard, in reply, said that as a man grew 
old he began to think of what he had done. Whatever 
effort or labour he had devoted to the work of the Institute 
of Chemistry, he felt he did not deserve all the President 
had said. He had served on the Council under Sir Edward 
Frankland, and it was a great pleasure to receive the 
Address from his son. The founders of the Institute 
worked hard and with self-sacrifice for the Institute. 
They had nothing to gain, and were looked upon as wild 
enthusiasts in trying to make a profession of chemistry. 
There was at that time just a beginning of the profession ; 
now the Institute could look back on the splendid work of 
the past, and it was for the younger men to work for its 
progress in the future. 

On the motion of Mr. Howard, seconded by Prof. J. 
Millar Thomson, a vote of thanks was accorded the 
President for his Address. Prof. Thomson endorsed 
much of what had been said on the subject of research. 

The President having replied, the Report of the 
Scrutineers was received. The following were elected 
Censors : — Prof. Percy F. Frankland, Mr. David Howard, 
Sir William Ramsay, and Prof. J. Millar Thomson. 



Mr. Walter F. Reid, Mr. G. T. HoUoway, and Mr. 
R. E. Alison were elected Hon. Auditors, and the Officers 
and Council were declared elected as follows : — 

President— G, T. Beilby, LL.D., F.R.S. 

Vice-Presidents— B. Dyer, D.Sc. ; M. O. Forster, D.Sc, 
F.R.S. ; P. F. Frankland, LL.D,, Ph.D., F.R.S. ; O. 
Guttmann, M.Inst.C.E. ; E. G. Hooper; R. Meldola, 
F.R.S. 

Hon. Treasurer — A. Gordon Salamon, A.R.S.M. 

Members of Council — L. Archbutt ; W. J. A. Butterfield, 
M.A. ; R. F. Carpenter; F. H. Carr ; C. E. Cassal, Col., 
V.D, ; A. C. Chapman ; F. D. Chattaway, M.A., D.Sc, 
F.R.S. ; A. C. Claudet, A.R.S.M. ; H. G. Colman, M.Sc, 
Ph.D. ; J H. Coste ; A. W. Crossley, D.Sc, F.R.S. ; 
W. W. Fisher, M.A. ; W. C. Hancock, B.A. ; O. Hehner ; 
G. G. Henderson, M.A., D.Sc; W. R. E. Hodgkinson, 
Ph.D; F. G. Hopkins, M.A., M.B., D.Sc, F.R.S.; 
W. Macnab ; G. McGowan, Ph.D. ; G. T. Moody, D.Sc. ; 
K. J. P. Orton, M.A., Ph.D. ; W. J. Pope, M.A., M.Sc, 
F.R.S.; R. R. Tatlock ; O. Trigger; J. A. Voelcker, 
M.A., B.Sc, Ph.D.; A. F. Watson, B.Sc ; W. M. G. 
Young. 

With a vote of thanks to the retiring Officers and 
Members of Council, moved by Dr. Edward Divers, 
seconded by Mr. Thomas Tvrer, the meeting terminated. 



SOCIETY OF CHEMICAL INDUSTRY. 
(London Section). 

Ordinary Meeting, March ist, 1909. 
Dr. Lewkowitsch in the Chair. 



By 



"On some Requirements of a Colour Standard." 
J. W. Lovibond. 

This paper deals with the various factors which influence 
the accuracy of observation in colour measurements and 
with some of the requirements oi colour standards. It 
first treats of the advantages and disadvantages of some 
sources from which colour standards may be derived, such 
as the spectrum, pigments, light, &c. Then with the 
lights available for illuminating colours under examination, 
demonstrating the unreliability of direct lights, and showing 
how a reliable light may be obtained, demonstrating also 
the limits of luminous intensity between which colour 
measurements can be made. An important factor in the 
connection is the angle at which substances are viewed, it 
having been found that the different colours differ in this 
respect ; red, for instance, varies greatly as the angle of 
incidence widens from forty degrees, whilst green is hardly 
affected. Other disturbing factors are dealt with, such as 
the differences in the colour intensity of pigments, the 
greater sensitiveness of trichromatic and printing and 
writing inks to light fluctuations compared to most other 
pigments. 

"Studies on Malting. Part I. The Production of 
Diastase during the Germination of Barley on the Malting 
Floors." By Arthur R. Ling, I<. I. C, Theodore Rendle, 
and George McLaren. 

The authors discuss the present state of our knowledge 
on the production of diastase during the germination of 
barley, and conclude that this production is not restricted 
to that portion of the endosperm adjacent to the columnar 
epithelium of the scutellum as stated by Brown and Morris, 
but that it is formed in all parts of the endosperm. They 
have determined the diastatic power of sections of the 
corns of barley during several stages of the steeping and 
flooring processes, and have obtained the following 
results : — 

During the steeping process the embryo is free from 
diastase, and the diastatic power of the barley remains 
constant. It is, however, possible that some augmentation 
of diastatic power occurs at this stage, for there is an 
apparent wandering of the enzyme towards the proximal 



Chemical News, I 
March 12, igog f 



Vacuum Tube Phenomena, 



131 



end of the corn. Since it is highly improbable that diastase 
diffuses, the probable explanation of this apparent wandering 
is that salts diffuse towards the embryo, leaving the diastase 
in the distal end less soluble and therefore less active, 
this being balanced by a small production of diastase in 
the other portions of the corn. On the floors there is a 
general increase in diastase in all partsof the corn, showing 
first in the proximal, then in the medial, and finally in the 
distal portion. The apparent production of diastase is 
greatly stimulated at the withering stage. 

The authors' experiments prove that the bulk of 
the diastase, not only in the resting corn, but at all 
stages of germination, is localised in that portion of the 
endosperm adjacent to the columnar epithelium of the 
scutellum, which is in agreement with the observation of 
Brown and Morris. They consider that enzymes may be 
formed as katabolic products of protoplasm, and they reject 
as improbable the explanation of Brown and Morris that 
diastase is formed by the direct secretory powers of various 
organs. It seems probable, however, from the position in 
which enzymes occur in the corn, that they are preferably 
formed from reserve rather than from histological protein, 
although both are to be regarded as sources. The authors 
suggest that diastase may be formed by the action of the 
proteolytic enzyme on the protoplasmic contents of the 
cell, the process being one of autodigestion (Ford and 
Guthrie, yourn. Inst. Brewing, 1908, xiv., 61). They 
show that when barley flour is made into a dough with 
water, and kept at the temperature of the room, a con- 
siderable increase in diastatic power occurs. 

"Sulphur as a cause of Corrosion in Steel." By G. 
Nevill Huntly. 

In a case of pitting in a stand-by boiler each pit was the 
centre of a blister. The liquid inside the blister was found 
to be quite different from the boiler fluid in composition, 
the former consisting of a slightly acid solution of ferrous 
sulphate, whilst the boiler water was alkaline with caustic 
soda. Reasons are given for supposing that the manganese 
sulphide in the steel is oxidised to sulphuric acid and an 
oxide of manganese, and that this acid acts locally on the 
surface of the boiler plate in the neighbourhood of the 
particle of manganese sulphide. 



RONTGEN SOCIETY. 

Mr. Alan A. Campbell Swinton read a paper on " Some 
Vacuum Tube Phenomena" at the last meeting of this 
Society on March 4th, and carried out a number of 
interesting experiments on high temperature effects with 
the cathode rays. One experiment of great interest was 
the entire conversion of a diamond into coke by means of 
the electric discharge. The cathode ray furnace for this 
purpose consisted of a glass tube with two concave cathodes 
focussing upon the diamond, which was placed upon an 
iridium plate supported by a platinum cup. Alternating 
current was applied to the terminals, and the temperature, 
measured by an optical pyrometer at the time of the 
diamond's conversion, was 1890° C. Mr. Swinton said 
that one of the points that could be investigated by this 
experiment was as to whether or not the diamond consisted 
of carbon containing dissolved in it one of the rare gases, 
such as krypton, argon, and neon. A spectrum of the 
residual gas was taken before the conversion of the diamond 
in the tube, and another spectrum after the conversion and 
the two spectra were practically identical. This seemed 
to prove conclusively the absence of these rare gases, 
although nitrogen and the commoner elements were found. 
Speaking of the manufacture of rubies, Mr. Swinton said 
that in such an experiment it was very necessary to keep 
the current down relatively to the vacuum in order to 
avoid the " Canal " rays, which appeared suddenly and 
had a tendency to crack the glass. In the manufacture of 
rubies a little pellet of pure alumina was taken, and to this 
was added a small quantity of chromium. If chromium 



were not used, sapphire was obtained instead of ruby. 
The ruby was mounted on a layer of alumina, which in the 
ordinary way fluoresced blue when bombarded by the 
cathode rays. After once being melted, however, it 
fluoresced red, but Mr. Swinton found that the red 
fluorescence was not due to the melting but to the presence 
of chromium, although the amount of chromium required 
to make the alumina fluoresce red was so small that if 
the alumina were put in a tube that had once been used 
for melting rubies there was always sufficient trace of 
chromium left in it to cause the red fluorescence. 

A matter of particular interest to the Rontgen Society 
was also brought forward by Mr. Swinton. He had lately 
been making some experiments with regard to the blackening 
and consequent hardening of X-ray tubes. He made 
several pairs of cylindrical tubes, each pair having a kind 
of Siamese connection to a single stem. He made quite 
sure that the same amount of vacuum was in each tube, 
and then he allowed one of the tubes to become quite 
black upon its inner surface while its fellow remained quite 
clean. Under such conditions he found that it required 
twice as many volts to start the current through the black 
tube as through the clear one. His conclusion was that 
the mere presence of blackness on the inner surface of the 
tube increased its resistance, quite irrespectively of the 
degree of vacuum. In other words, the hardening and 
depreciated utility of the tube has nothing to do with the 
vacuum, but is due to the presence of a conducting film 
upon the glass. 

A long discussion upon this effect took place, in the 
course of which Mr. W. Duddell said that he thought it 
possible that the high resistance of the inner coating 
allowed the cathode to come nearer to the anode, thereby 
increasing the tube's resistance. 



NOTICES OF BOOKS. 

The Methods of Textile Chemistry. By Frederic 
Dannerth, Ph.D. New York: John Wiley and Sons. 
London : Chapman and Hall, Ltd. igo8. 
This book gives exactly the course of practical work 
which is most suitable for the technical student who 
wishes to make a special study of the textile industries, 
and at the same time the chemist who is already engaged 
in such work will find that he can gather hints on practical 
methods from it. The first part deals with the qualitative 
analysis of wool and hair fibres, and describes methods of 
determining the physical differences between the various 
fibres, and thus identifying materials composed of or con- 
taining them. The reactions of the most important organic 
finishing materials are shown in a tabular form. Part II. 
discusses the quantitative analysis of various classes of 
fabrics, and also of the raw materials of which they are 
made, full experimental details being given for the per- 
formance of all the tests described. Methods of calculating 
results are explained by means of typical examples, and 
some tables of actual results obtained with various speci- 
mens of fibres are included. In the third part of the book 
a very short outline is given of a few important textile 
processes, such as cotton bleaching and mercerisation. 



Les Erreurs de la Science. (" The Errors of Science "). By 
Louis-Charles-Emile Vial. Paris : Published by the 
Author. 1908. 
The author of this book believes that there are advantages 
to be gained by a return to the system of the ancients who 
believed in philosophising without appeal to experimental 
facts, and he advocates discarding modern methods of 
gaining knowledge by experiment, with a corresponding 
neglect of the exercise of the reason. Certainly, he cannot 
be accused of leaving hypotheses alone and searching for 
facts, and the book teems with the most fanciful flights of 



13^ 



Meetings for the Week, 



I Chemical UzVfi, 
I March 12, 1909 



the imagination. The fundamental argument, which is 
worked out at wearisome length, is that contraries are the 
generative principle of all acts, and that the Universe is 
nothing but a dynamical male and female couple of 
Force and Matter. 



CHEMICAL NOTICES FROM FOREIGN 
SOURCES. 



Berichte der Deutschen Chemischen Gesellschaft. 
Vol. xlii., No. 2, igog. 

Absorption of Hydrogen by Metallic Nickel. — A. 
Sieverts and Joh. Hagenacker. — According to the experi- 
ments of Sieverts and Beckmann, i volume of nickel 
between 377° and 580° absorbs 025 to 0-5 volumes of 
hydrogen, while Mayer and Altmayer have recently stated 
that much larger quantities of hydrogen are absorbed. The 
authors have performed many experiments with nickel at 
various temperatures, and have confirmed the former 
experimenters' results. They have also determined the 
influence of pressure on the absorption of hydrogen by 
nickel. At 822° and g23'' the absorption is not proportional 
to the pressure, but is very nearly proportional to the 
square root of the pressure. 

Triphenylmethyl.— M. Gomberg.— Triphenylcarbinol 
chlorides exist in a tautomeric condition in liquid sulphur 
dioxide, namely, as quino-carbonium salts. Their colour 
and also the mobility of the halogen atoms in the para- 
position must be ascribed directly to this tautomeric con- 
dition. As carbinol sulphates behave in all solvents like 
the carbinol haloids in liquid sulphur dioxide, it must be 
deduced that they are also quino-carbonium salts in all 
solvents. In a previous communication on triphenyl- 
methyl, it was suggested from analogy that the acid 
carbinol sulphates, the double salts of the carbinol haloids 
with metallic haloids, and the metal-organic derivatives of 
the triphenylmethane series must all correspond to the 
quinoid type. Schmidlin has independently come to the 
•ame conclusion as regards the metal-organic compounds. 

Some New Fluorides. — Otto Ruff. — Niobium penta- 
fluoride, NbFj, may be prepared by acting on niobium, 
obtained from the pentoxide, with elementary fluorine at 
250°. It forms colourless, strongly refracting crystals 
which melt at 72° to 73°, and boil in glass vessels under 
760 mm. pressure at 236°. The residue remaining in the 
flask is light blue. Niobium pentafluoride is very hygro- 
scopic, quickly deliquesces in air, and gives a clear solu- 
tion with water, without separation of niobic acid. With 
caustic soda fluoxyniobate is precipitated. Caustic soda 
and ammonia precipitate niobic acid from a solution of the 
fluoride in water. Tantalum pentafluoride, TaFj, can be 
prepared by a similar method. It also forms colourless 
strongly refracting crystals which are hygroscopic and 
deliquesce in air. They melt at g^° and boil at 225° to 
226-5°. Dry glass is attacked by tantalum pentafluoride 
only very slowly at the ordinary temperature, but at higher 
temperatures tantalic acid is formed. When uranium is 
subjected to the action of fluorine a violent reaction occurs, 
and a black mass is first formed, and then light green pro- 
ducts, consisting chiefly of uranium tetrafluoride and con- 
taining some oxyfluoride. are obtained, while only small 
quantities of the hexafluoride can be prepared by this 
method. The reaction occurs far more quietly if uranium 
pentachloride is used instead of the metal itself. When 
heated with fluorine this readily yields the hexafluoride at 
a low temperature. UFe forms colourless monoclinic 
crystals, fuming in air. It sublimes on heating without 
melting. It is very hygroscopic, gives a clear yellowish 
green solution with water, and reacts with glass in presence 
of traces of water. The latter acts as a catalytic agent, 
and the products of the reaction are silicon tetrafluoride 
and uranium oxyfluoride. 



Products of Arc and Spark Discharge in Liquid 
Argon and Nitrogen, Tin Nitride and Pyrophoric 
Tin. — Franz Fischer and George Iliovici. — The authors 
have studied the products of the arc and spark discharge 
of various metals in liquid argon and in nitrogen. When 
tin is used a substance is obtained which is a mixture of 
metal, nitride, and oxide. When this substance is heated 
pure nitrogen is given off. In subsequent experiments 
first the oxygen and then the nitrogen was removed from 
the liquid argon ; oxides were first formed, then nitride, 
and finally pyrophoric tin. A gasometer was then con- 
structed, in which the argon could be purified by means of 
a calcium arc. The calcium arc is not effective until the 
strength of the current is great enough to evaporate 
the calcium on the walls of the gasometer, and after such 
treatment the residue after ignition of the substance 
in vacuo is pure tin, and the generation of nitrogen 
gradually ceases altogether, 



MISCELLANEOUS. 

Royal Photographic,Society of Great Britain. — An 
Exhibition of Photographs, by members of Societies 
affiliated with the Royal Photographic Society of Great 
Britain , at 66, Russell Square, will be open to the public daily 
(on production of visiting card) from March loth to April 
loth, between the hours of 11 a.m. and 5 p.m, ; Saturdays, 
n a.m. till 2 p.m. A number of photographic societies 
throughout the kingdom (representing in all a membership 
of about 15,000) are affiliated to the Royal Photographic 
Society of Great Britain, and some of the best workers in 
these societies enter their pictures in an annual competi- 
tion. These pictures are submitted to the Board of Judges, 
who select about fifty of the most noteworthy for circula- 
tion among the societies. The prints selected from the 
igo8 competition are now on view at the above address. 
These prints may be considered as representing the high- 
water mark in pictorial work attained by the members of 
the competing societies, and it is to the authors of these 
pictures that we look to maintain and raise the standard of 
photographic work in the future. A novel and educational 
feature in the present Exhibition is the inclusion of a 
number of sketches by W. J. Morgan, R.B.A., of Bir- 
mingham, who shows how a painter would treat the sub- 
jects selected by the photographers, and comparison of the 
pencil sketches with the photographic prints should be as 
interesting to the public generally as to those whose works 
have been selected for this distinction. 



MEETINGS FOR THE WEEK. 

Tuesday, i6th.— Royal Institution, 3. "Evolution of the Brain as 

an Organ of Mind," by Prof. F. W. Mott, F.R.S. 
Wednesday, 17th.— Microscopical, 8. "Optical Examination of a 

Crystal Section in a Rock Slice," by Dr. J. W. 

Evans. 

Royal Society of Arts, 8. " The Musical Aspect 

of Drums," by Gabriel G. Cleather (assisted by 
Mrs. Stanfeld Prior at the Pianoforte). 
Thursday, 18th.- Royal Institution, 3. " Recent Advances in Agri- 
cultural Science," by A. D. Hall, M.A. 

Chemical, 8.30. " Iodine Dioxide," by M. M. P. 

Muir. "The Constituents of the Rhizome of 
Apocynum androraemifo'iufn" by C. W. Moore. 
" Action of Phosphorus Pentachloride on the 
Methylene Ethers of Catechol Derivatives— Part 
IV., Derivatives of Dihydro.xyphenylacetic, 
-glycolic, and -glyoxylic Acids," by G. Barger and 
A. J. Ewins. "Studies in the Azine Series — 
Part I., The Constitution of Safranine," by J. T. 
Hewitt, S. H, Newman, and T. F. Winmill. 
"The Condensation of Amides with Esters of 
Acetylenic Acids," by S. Ruhemann, " Polari- 
metric Method of Identifying Chitin," by J. C. 
Irvine. "Studies in Asymmetric Synthesis — 
VII., Influence of the d-Amyl Group," by A. 
McKenzie and H. A. Mijller, 

Friday, 19th.— Royal Institution, 9. " Experiments at High Tempera- 
tures and Pressures," by R. Threlfall, F.R.S. 

Saturday, 20th.— Roval Institution, 3. " Properties of Matter," by 
Prof. Sir J. J. Thomson, F.R.S, 



Chemical News, 
March 19, 1909 



Chemically Treated Flours. 



133 



THE CHE MiCAL NEWS 



Vol XCIX., No. 2573. 



THE METALLOIDS ARSENIC AND ANTIMONY 

FROM A THERMO-CHEMICAL STANDPOINT. 

By J. C. THOMLINSON, B.Sc. 

The hydrogen compounds of these elements, as well as 
those of nitrogen and phosphorus, show a continually 
decreasing heat of formation with increase of atomic 
weight. 

Heat of formation (cals.). 

NH3 ii-gio 

PH3 4627 

AsHj -43770 

SbH3 -84-500 

With the exception of ammonia, NH3, these results are 
widely different from what we would be led to expect from 
a consideration of the heats of combination of phosphorus 
and hydrogen as derived from the chlorides of these ele- 
ments (Chemical News, xcv., 145), and of those of the 
metalloids as derived from their respective chlorides. This 
is due to the fact that these hydrogen compounds are 
gases, and the elements phosphorus, arsenic, and anti- 
mony are solid at the temperature for which the data are 
reckoned, 18 — 20° C. Hence allowance must be made for 
the latent heats of fusion and volatilisation of these ele- 
ments, and in general for the difference of heat content 
between the solid and gaseous state at this temperature. 

If this correction were made, we would obtain a distinct 
proof of the correctness of the views which we are about 
to formulate as to the heats of combination of the metal- 
loids, as well as to that of phosphorus, already dealt with. 

The heats of formation of the trichlorides of these ele- 
ments are given below, and we regard the atom of chlorine 
taking part in these reactions as having a heat value equal 
to i4"530 cals. 

Heat of formation (cals.). 

PCI3 75-300 

ASCI3 7i'390 

SbCl3 9i'390 

From these we at once find the heat of combination of 
trivalent phosphorus, arsenic, and antimony to be respect- 
ively 31 '710, 27-800, and 47-800 cals. 

Placed side by side with their atomic weights, the 
amounts of heat absorbed by phosphorus, arsenic, and 
antimony in assuming the gaseous state in their hydrides 
are seen to be roughly proportional to these atomic 

weights. 

Cals. Atomic weight. 

P .. .. 49'493 31 

As .. .. 93'98o 75 

Sb .. .. 154-710 120 

In this calculation, as in what follows, the heat of com- 
bination of hydrogen is taken to be 7-470 cals. 

In dealing with the chlorides, oxides, and oxygen acids 
of these elements we will first take phosphorous acid, — 

^O— H 
0-P^O 

/\ 
H H 

PB = 3^340 

O— = 71-405 

7i'405 

52-545 
- 22-410 ' 



TT pQ ( 227-700 crystallised acid 
3 3 1 224-600 aq acids 

The result by experiment is comparable with that ob- 
tained by calculation. 

Arsenic trichloride, ASCI3 has a heat of formation 71-390 
cals., giving us trivalent arsenic, As= = 27-800 cals. : — 



As- 


— As 


II 


II 





1 



^O^ 

If we regard arsenic trioxide as having the above 
structural formula, with trivalent oxygen 0= = 33-685 
cals., the calculated heat of formation is 156-655 cals., the 
experimental value being 154-670 cals. 



As- 



-As 



O \ O 

\ \/ 
Or:0— O 

Similarly, with arsenic pentoxide and one valency of an 
oxygen atom exerting a central influence in the molecule, 
the calculated and experimental heats of formation are 
224-025 and 219330 cals. respectively. 

As regards antimony, I have no data at hand for the 
anhydrous oxides. 



A SIMPLE METHOD FOR DETERMINING 

VAPOUR- DENSITIES. 

By PHILIP BLACKMAN. 

Among the references at the beginning of the paper in the 
Chemical News, 1909, xcix., p. 87, should be included 
Zeitschrift f^r Physikalische Cfiemie, 1909, Ixv., 550 (but 
read there I instead of S and Ic instead of Sc). Also, in 
the Chemical News {ibid.), instead of — 



250-105 



read — 



, _ 31068 w Z Lc (273-1-^1) 
, _ 31068 w ZLc (273 f ^i) 

"JMVTahlT^/)"* 



CHEMICALLY TREATED FLOURS.* 

By E. F. LADD, Food Commissioner and ChemiBt. 

(Concluded from p. 129). 

II. Effect of Bleached Flour Extracts on Rabbits. 

By E. F. Ladd and H. L. White. 
After reading the Address of Prof. Shepard, of South 
Dakota, with regard to the effect of nitrous acid in retarding 
or inhibiting digestion, and after considering the effect of 
other food preservatives, as reported upon by Dr. Wiley in 
various reports of experiments carried on by the Bureau of 
Chemistry, Department of Agriculture, it has seemed that, 
if flours contained varying quantities of nitrous acid, 
nitrites, or other toxic bodies, extracts from such flours 
would, if fed to animals, result in some physiological 
action, and especially in action upon the blood corpuscles, 
diminishing the oxyhemoglobin with a corresponding in- 
crease in the metahemoglobin, and in showing other con- 
ditions which would be noticeable when the various parts 



* Special Bulletin from the Government Agricultural Experiment 
Station, Agricultural College, N.D., December, 1908. 



i34 



Chejnically Treated P lours. 



I Chemical News, 
I March 19, 1909 



and organs of the body were carefully examined. It was 
then, after consultation with Dr. Van Es, decided to under- 
take such an experiment. A large amount of preliminary 
work in methods of extraction and the preparation of 
samples was undertaken in order to find out how best to 
prepare extracts which could be used. 

The first attempt was to prepare an aqueous extract of 
three samples of flour — the unbleached, the commercially 
bleached, and the over-bleached, the latter being for the 
purpose of magnifying the results. It was found, in the 
case of the commercially bleached flours, impossible to 
concentrate the aqueous extracts without losing in the dis- 
tillate of water all of the nitrous acid or nitrite reacting 
material, and this part of the experiment was, for the time 
being, necessarily abandoned until a method could be 
devised whereby concentration could be secured under 
such conditions as to permit of retaining the toxic material 
which might be extracted. 

These experiments were carried on with the assistance 
of Prof. White and Dr. Van Es. The results of these ex- 
periments are indicated in the following detailed report: — 
In order to determine the eff^ects of bleached flour on an 
animal organism, alcoholic extracts of over-bleached and 
commercially bleached flours were prepared and ad- 
ministered to rabbits. As a control alcoholic extracts of 
an unbleached flour were also prepared and administered 
to rabbits ; and, as a further check, physiological salt 
solutions containing alcohol, ranging from 7 to 16 per cent, 
were administered to other lots of rabbits. 

The flour having the laboratory number 5489 was found 
to be commercially bleached, the same having been pur- 
chased on the market, and was used to prepare the 
alcoholic residues. This flour contained 30 pans per 
million of nitrite reacting nitrogen, or as sodium nitrite 
15-0 parts. The flour No. 204 was used for the unbleached 
esidues. Some of this same flour (No. 204) was subjected 
to the action of nitrogen peroxide until it assumed a 
marked yellow colour, and this product was used in the 
preparation of the over-bleached residues. The nitrogen 
peroxide used in this bleaching was generated by allowmg 
nitric acid to act on strips of copper. The gas as generated 
was passed through a 2oinch coiled reflux condenser in 
order to condense all free acid, and the gas so collected 
was used in the preparation of the over-bleached flour. 

The alcoholic extracts were prepared by shaking up 
portions of 2000 grms. of the flour, in lots of 500 grms. 
each, with 95 per cent alcohol. The shaking was con- 
tinued at intervals for several days. The alcohol was then 
distilled off' in an atmosphere of hydrogen and under 
reduced pressure. The residue in each case was a little 
less than 100 cc. The residue from the over-bleached flour 
was so thick and viscous that it was found necessary to add 
a little alcohol so that it could be made thin enough to be 
administered. About 7 cc. of alcohol was added to the 
residue from the over-bleached, and that from the com- 
mercially bleached flours, enough to bring the volume of 
each residue up to 100 cc. 

The residue from the alcoholic extracts of over-bleached 
flour was, as already stated, a thick viscous substance, 
orange-yellow in colour, strongly acid in reaction, and 
having a strong odour. When put on the hands it made 
a yellow stain which was removed with considerable diffi- 
culty. When a small portion of the residue was moistened 
with ammonium hydroxide it gave a reaction similar to the 
xanthoproteic reaction, which is obtained by boiling proteid 
material with nitric acid, cooling, and theamoistening with 
ammonium hydroxide. 

The alcoholic residues from the commercially bleached 
and from the unbleached flours were thin yellow liquids, 
slightly acid in reaction. The alcoholic extracts were ad- 
ministered to rabbits by means of a stomach tube and a 
syringe, and in each case, before withdrawal of the tube, it 
was rinsed out with distilled water. By the use of the 
stomach tube none of the acid residues came in contact with 
the esophagus, so that the possibility of death from a 
secondary cause, such as strangulation, was eliminated. 



Results of Experiments. 
Series II. 
Alcoholic Extract, Over-bleached Flour. Amount of 
extract 100 cc. Each rabbit marked with string 
in ear. 
Rabbit No. Amount (cc). Remarks. 

1 (large grey) 15 Collapse in fifty minutes ; died in 

three hours. 

2 10—12 Violent convulsions ; dead in 

fifteen minutes. 

3 10—12 Collapse in fifty minutes ; dead 

in three hours. 

Post-mortem Findings by Dr. L. Van Es. — All examina- 
tions were made immediately after death to exclude, as far 
as possible, post-mortem changes. 

Series II. : Rabbit No. i.— Heart in diastole ; lungs 
slightly hyperemic ; liver blenched ; where it has been in 
contact with the stomach, the liver has a boxwood colour ; 
kidneys salmon coloured, and cut surface is pinkish in 
colour ; stomach walls come asunder when slightly pulled ; 
on section, there is noticed complete erosion of mucose 
which strips off easily, blood not coagulated. 

Rabbit No. 2. — Lungs not contracted by hyperemic, 
emphymacetous, liver hyperemic, blenched wherever in 
contact with stomach walls, stomach contents escaped 
owing to almost complete erosion of stomach walls, 
kidneys slightly hyperemic, blood not coagulated. 

Rabbit No. 3. — Lungs fully contracted, blenched on 
surface with hyperemic areas, heart in diastole, liver 
hyperemic, and where in contact with stomach walls, 
blenched and friable, stomach walls almost completely 
eroded, blood not coagulated. 

Series IV. 
Alcoholic Extract, Commercially Bleached Flour. (Flour 
No. 5489). Amount of extract 100 cc. Rabbits 
marked with string in ear. Pen V. (Sept. 16, 1908, 
11.30 a.m.). 
Rabbit No. Amount (cc). Remarks. 

1 10 Collapse in thirty minutes ; dead 

in three and a-half hours. 

2 10 Collapse in thirty minutes ; dead 

in three and a-half hours. 

3 10 Collapse in forty minutes ; re- 

covered and seemed well at 8 a.m. , 
Sept. 17. 

Extract had a decided odour of alcohol ; contained about 
7 per cent. 

Second Administration (Sept 17, 1901, 11 a.m.). 

Rabbit No. Amount (cc). Remarks. 

3 10 Immediate collapse and dead in 

fifteen minutes. 

Series IV. Post-mortem Findings: Rabbit No. 1. — 
Lungs normal, heart in diastole, blood poorly clotted, 
liver^ somewhat congested, kidneys normal, intestines 
normal, spleen normal, stomach intact, contents slightly 
acid, hyperemic condition with erosin of mucosa, walls 
somewhat edematous ; stomach preserved in 4 per cent 
formalin. 

Rabbit No. 2. — Heart in diastole, lungs hyperemic, 
blood poorly clotted, kidneys normal, intestines normal, 
spleen normal, liver hyperemic, stomach intact, contents 
acid, wall of stomach edematous with slight superficial 
erosion of mucosa. Stomach preserved in 4 per cent 
formalin. 

Rabbit No. 3. — Lungs normal, heart in diastole, blood 
clotted normally, intestines normal, kidneys slightly con- 
gested, liver normal except slightly blenched where in 
contact with stomach, spleen normal, stomach intact, 
contents acid, stomach shows slight superficial erosin, no 
hyperemia. 



Chemical News, • 
March 19, igoq • 



Chemically Treated Flours. 



135 



Alcoholic Extract of Unbleached Flour. Amount of 
Extract 100 cc, Pen II. (Sept. 16, 1908, 11.45 a.m.). 
Rabbit No. Amount (cc). Remarks. 

1 10 Some discomfort manifested for 

2 10 two or three hours, but seemed 

3 (large grey) 15 all right again in five hours. 

Second Administration (Sept. 17, 1908, 11. 15 a.m.). 

1 10 Did not seem to affect rabbits in 

2 10 any way. 

3 15 

Third Administration (Sept. 18, 1908, 11 a.m.). 

1 10 Did not seem to leave any effect. 

2 — 

3 15 

Series VII. 
Physiological Salt Solution. Pen II. (Sept. 16, 1908, 
12 noon). 
Rabbit No. Amount (cc). Remarks. 

1 10 Rabbits not affected. 

2 15 

3 10 

Second Administration (Sept. 17, 1908, 11.30 a.m.). 

1 10 Not affected. 

2 12 

3 15 

Third Administration (Sept. 18, 1908, 11. 15 a.m.). 

1 10 Not affected. 

2 15 

3 15 

Series VIII. 

Physiological Salt Solution containing Alcohol. Pen III. 
(Sept. 16, 1908, 12 noon). 
Rabbit No. Amount (cc). Remarks. 

1 10 Salt solution contains 7 per cent 

2 lo alcohol. Not affected. 

3 12 

Second Administration (Sept. 17, 1908, 11.30 a.m.). 

1 10 Salt solution contains 14 per cent 

2 15 alcohol. Not affected. 

3 15 

Third Administration (Sept. 18, 1908, 11. 15 a.m.). 

1 ID Salt solution contains 16 per cent 

2 10 alcohol. Not affected. 

3 12 

The results of these experiments were so striking that 
when taken together with previous investigations made by 
the department would seem to indicate that other toxic 
bodies, aside from nitrites, must be present in the flour, and 
this bears out the results of tests previously made on the 
fat as indicating a nitrated or nitro derivative resulting from 
the action of bleaching agents upon the fat or oil of the 
flour ; and, further, indicates the correctness of the 
assumption based upon the experiments that nitrous acid 
or nitric acid, or products resulting therefrom, have 
reacted upon the gluten, apparently producing, as previously 
shown, diazo compounds, and it is a well known fact that 
some of the diazo compounds are exceedingly poisonous. 
If this is true then there should be remaining in the aqueous 
extract, from the over-bleached flour, sufficient of other 
toxic bodies to produce some physiological effect when fed 
to rabbits, although all of the nitrous acid or nitric reacting 
material was lost in the distillate in the attempt at 
concentration. 

However, the aqueous extract or residue prepared from 
over-bleached flour, the same as was used for preparing 
the alcohol residue from over-bleached flour, was tested. 



The aqueous extract was brown or blackish in colour, of 
syrupy consistency, had the odour of caramel, and gave a 
strong acid reaction. 200 cc. of this extract was prepared 
of such a strength that 10 cc. represented the extract from 
100 grms. of flour, or, approximately, the amount of extract 
from the flour which would be used in the preparation of 
one-fourth loaf of bread. 

The results of feeding experiments as conducted in 
previous cases were as follows : — 

Series I. 
Aqueous Extract of Over-bleached Flour. Amount ot 
Extract 200 cc. Pen I. (Sept. 16, 1908). 
Rabbit No. Amount (cc.)- Remarks. 

1 (large grey) 15 Collapse in ten minutes ; dead in 

two to two and a-half hours. 

2 ID Collapse in ten minutes ; dead in 

twenty to thirty minutes. 

3 10 Collapse in ten minutes ; dead in 

twenty to thirty minutes. 

Series I. : Rabbit No. i. — Stomach contents show 
strongly acid, and have escaped into peritoneal cavity 
owing to perforation of stomach by erosion. Where 
stomach contents have been in contact with the liver, the 
liver tissue is friable and blenched on the surface. Escape 
of stomach contents is probably post-mortem owing to lack 
of inflammatory changes. Heart in diastole, lungs 
hyperemic, kidneys slightly hyperemic, blood poorly 
coagulated. 

Rabbit No. 2. — Stomach yet intact, but on withdrawal, 
stomach walls pull asunder. On inner side evidence of 
h}'peremia of mucosa. Liver friable and blenched on sur- 
face, kidneys hyperemic, lungs hyperemic, heart in 
diastole, intestines apparently normal, blood poorly 
coagulated. 

Rabbit No. 3. — Lungs hyperemic, heart in diastole, 
blood poorly coagulated, liver hyperemic, kidneys slightly 
hyperemic, stomach intact, mucosa eroded and adhering to 
stomach contents. 

In a previous series of experiments alcoholic and aqueous 
solution of over-bleached flour were fed to rabbits with 
fatal results, death resulting in from fifteen minutes to 
three hours. At the post-mortem examinations of these 
rabbits it was found that the stomach of each rabbit was 
either perforated or easily pulled apart, indicating that the 
extracts exerted on the stomach walls a marked corrosive 
action. As these extracts had a strong acid reaction, and 
in order to determine whether the extracts had a toxic as 
well as corrosive effect, both extracts were neutralised with 
sodium bicarbonate, and then administered as in the 
previous series of experiments. 

Series IX. 
Aqueous Extract Over-bleached Flour, neutralised with 
sodium bicarbonate. Pen IV. (Oct. 12, 1908, 
4.40 p.m.). 
Rabbit No. Amount (cc). Remarks. 

1 (grey) 12 Hindquarters paralysed in 

one hour. Died during 
night of Oct. i2th. 

2 (white and grey) 12 Prostrate in ten minutes — 

heavy respiration — con- 
vulsions, died in one hour. 

Series X. 
Alcoholic Extracts Over-bleached Flour, neutralised with 
sodium bicarbonate. Pen II. (Oct. 12, igo8, 
4.30 p.m.). 
Rabbit No. Amount (cc). Remarks. 

1 (grey) 12 After ten minutes would not eat ; 

2 (white) 10 stretched out on floor. 

Second Administration (Oct. 14, igo8, 4.30 p.m.). 

1 8 Survived treatment, but was not in 

2 8 good condition. Died during 

night. 



136 



Improvements in Production and Application of Giincotton, &c. {^u^'^'^igUl'^^' 



Post-mortem Findings. Series IX : Rabbit No. 2. — No 
coccidiosis in liver, heart normal, stomach congested, 
lungs normal, kidneys congested, odour of viscera same as 
that of extract, mucosa of stomach congested. 

Rabbit No. i. — Same findings as for rabbit No. 2. 

Senes X : Rabbit No. 2. — Stomach congested, liver 
showed coccidiosis. 

Alcoholic Extract of Unbleached Flour. 
A second alcoholic extract of unbleached flour was pre- 
pared by extracting 2000 grms. of flour with alcohol and 
concentrating to 100 cc. over a low flame. The extract 
was a thick liquid with the odour of alcohol, and on 
standing separated into two layers. The top layer was 
brown in colour, and looked like a fat ; the lower layer was 
straw-coloured. This extract was administered to rabbits 
n the manner as in previous experiments. 

Series. XI. (Oct. 20, igo8, 5 p.m.). 
Rabbit No. Amount (cc). Remarks. 

1 15 No ill effects noted. 

2 15 

3 " 

Second Administration (Oct. 21, igo8, 4 p.m.). 

1 15 No ill effects noted. 

2 15 

3 — 

The fact seems to have been clearly established that 
commercially bleached flour, such as we found on the 
market and purchased for use in this experiment, did 
contain toxic bodies in sufficient quantity to cause death in 
animals to which the same was fed as an extract. 

Conclusions. 
As the result of the experiments presented in this and 
other reports we feel justified in summarising the following 
facts : — 

I. There is produced in flour, as the results of artificial 
bleaching, toxic bodies. 

II. Experiments previously reported indicate the possi- 
bility of a diazo reaction where flour has been subjected to 
bleaching, especially when the bleaching has been carried 
to a considerable extent. 

III. The fact that the xanthoproteic reaction takes place 
demonstrates that the bleaching agent has acted upon the 
gluten or the protein of the flour. 

IV. Alcoholic extracts prepared from unbleached flour 
and fed to rabbits did not affect them. 

V. Alcoholic extracts prepared in the same manner from 
commercially bleached flour and fed to the rabbits in the 
same way caused their death within a few hours. 

VI. Alcoholic extracts prepared from over-bleached flour 
in the same manner and fed in the same way to rabbits 
caused their immediate collapse and death. 

VII. Aqueous extracts prepared from over-bleached 
flours when fed to rabbits caused their immediate collapse 
and death. 

VIII. Alcohol and aqueous extracts from over-bleached 
flour, when neutralised with sodium bicarbonate, and fed 
to rabbits, caused the death of the rabbits in a short time, 
demonstrating that it was not the acidity that produced 
the death of the rabbits. 

IX. — In preparing aqueous extracts all nitrite reacting 
material disappeared ; hence, the death of the rabbits ; in 
this case, must have been due to the presence of other 
toxic material than that of nitrites. 

While no decision has been rendered, at the time of this 
writing, by the District Court, it is of interest to the public 
to know that the Secretary of Agriculture, after carefully 
considering the question of bleached flour in all its phases, 
has recently rendered a decision with regard to the status 
of flour bleached by chemical means under the Food and 
Drugs Act of June 30th, 1906. This decision is fully set 
forth in the following telegram : — 



Washington, D.C., Dec. gth, 1908. 
"E. F. Ladd, Fargo, N.D. 

" You are advised that I have to-day issued the fol- 
lowing decision relative to bleached flour : — 

Bleached Flour, 

" Flour bleached with nitrogen peroxide, as affected by 
the Food and Drugs Act of June 30th, igo6, has been made 
the subject of a careful investigation extending over several 
months. A public hearing on this subject was held by the 
Secretary of Agriculture and the Board of Food and Drug 
Inspection, beginning November i8th, igoS, and continuing 
five days. At this hearing those who favoured the bleaching 
process and those who opposed it were given equal oppor- 
tunities to be heard. It is my opinion, based upon all the 
testimony given at the hearing, upon the reports of those 
who have investigated the subject, upon the literature, and 
upon the unanimous opinion of the Board of Food and Drug 
Inspection, that flour bleached by nitrogen peroxide is an 
adulterated product under the Food and Drugs Act of June 
30th, igo5. That the character of the adulteration is such 
that no statement upon the label will bring bleached flour 
within the law, and that such flour cannot be legally made 
or sold in the District of Columbia, or in the territories, or 
to be transported or sold in interstate commerce, or be 
transported or sold in foreign commerce except under that 
portion of Section 2 of the law which reads : — 

' , . . Provided, that no article shall be deemed mis- 
branded or adulterated within the provisions of this Act 
when intended for export to any foreign country, and pre- 
pared or packed according to the specifications or directions 
of the foreign purchaser, when no substance is used in the 
preparation or packing thereof in conflict with the Laws of 
the foreign country to which said article is intended to be 
shipped. . . .' 

" In view of the extent of the bleaching process, and of 
the immense quantity of bleached flour now on hand or in 
process of manufacture, no prosecutions will be recom- 
mended by this Department for manufacture and sale 
thereof in the District of Columbia or the territories, or for 
transportation or sale in interstate or foreign commerce for 
a period of six months from the date hereof.'' 

(Signed) James Wilson, Secretary of Agriculture. 



IMPROVEMENTS IN PRODUCTION 

AND APPLICATION OF GUNCOTTON AND 

NITROGLYCERIN.* 

By Colonel Sir FREDERIC L. NATHAN, R.A. 

The subject on which I have been asked to lecture to- 
night is one that has often been dealt with in this theatre 
by such great authorities as the late Sir Frederick Abel and 
Sir Andrew Noble. I feel it a great honour, therefore, to 
have been invited to deliver this discourse, but I realise 
that it is a very difiicult task I am attempting. Sir 
Frederick Abel was one of the greatest authorities on the 
chemistry of explosives, and used to deal with them mainly 
from the chemical point of view ; Sir Andrew Noble, on 
the other hand, is the greatest living authority on all that 
concerns artillery and ballistics, and he has considered 
explosives mainly from the ballistic standpoint. I am 
neither a chemist nor an artillerist, but occupy the much 
more humble position of a manufacturer of explosives, and 
I must ask your indulgence whilst I endeavour to describe 
the main features connected with the manufacture of gun- 
cotton and nitroglycerin, and to say a few words about 
cordite, essentially a combination of the two. 

For centuries the only explosive known to the world was 
that mechanical mixture of saltpetre, charcoal, and sulphur, 
called gunpowder. Chemical explosives may be said to 

* A Discourse delivered before the Royal Institution, January 29, 1909, 



Chemical Ne^vs, 
March 19, 1909 



Improvements in Production and Application of Guncotton, &c. 137 



date from the discovery of guncotton by Schonbein, and 
it is a fact worth noting on this occasion, that the first 
sample of guncotton in this country was one which accom- 
panied a letter of Schiinbein from Basle, dated March i8th, 
1846, and addressed to Michael Faraday at the Royal 
Institution. Sch mbein referred to guncotton in this letter 
as follows : — 

" There is another point about which I take the liberty 
to ask your kind advice. I am enabled to prepare in any 
quantity a matter which, next to gunpowder, must be 
regarded as the most combustible substance known. So 
inflammable is that matter that on being brought in con- 
tact with the slighest spark, it will instantly be set on fire, 
leaving hardly any trace of ashes, and if the combustion 
be caused within closed vessels, a violent explosion takes 
place. That combustible substance is, as I will con- 
fidently tell y«u, raw cotton, prepared in a simple manner, 
which I shall describe you hereafter. I must not omit to 
mention that water has not the least action upon my 
matter ; that is, that it may be immersed ever so long in 
that fluid without losing its inflam.nability after having 
been dried again. A substance of that description seems 
to be applicable to many purposes of daily life, and I 
should think that it might advantageously be used as a 
powerful means of defence and attack. Indeed, the Con- 
greveian rockets can hardly be more combustible than my 
prepared cotton is. What shall I do with that matter ? 
Shall I offer it to your Government ? I have enclosed a 
little bit of that really frightful body, and you may easily 
convince yourself of the correctness of my statements re- 
garding its properties." 

In a subsequent letter he gave this body the name of 
guncotton. 

Attempts to manufacture guncotton in accordance with 
the method devised by Sch inbein were made both in this 
country and abroad. Accidents which occur, however, 
both in great Britain and France in the early days of 
manufacture, led to the abandonment of attempts to pro- 
duce it in these countries; it was only in Austria that its 
production was persevered with, and a system of manu- 
facture worked out there by Baron von Lenk. Having 
succeeded in producing guncotton on the manufacturing 
scale, von Lenk turned his attention to adapting it for pro- 
pulsive purposes, and although at one time his efforts 
appeared to have met with a certain amount of success, 
and batteries of field artillery in Austria were actually 
equipped with guncotton cartridges, the difficulty of 
moderating its rate of combustion was never satisfactorily 
overcome. While this question was still the subject of 
experiments, serious accidents, due to the spontaneous 
combustion of guncotton in store, led to its production 
being given up even in Austria. 

In 1863, Sir Frederick Abel took up the study of the 
manufacture of guncotton in this country with a view to 
adapting it for propulsive purposes, and, at the same time, 
to improving its stability, so that its spontaneous com- 
bustion in store might be prevented. 

He was not successful in the first object, but as regards 
the production of guncotton of good stability, the modi- 
fications that he introduced into the von Lenk system of 
manufacture resulted in the production of stable guncotton. 
The process of manufacture devised by von Lenk was 
briefly as follows : — 

Skeins of long staple cotton yarn were immersed in a 
mixture of strong nitric acid of i"52 sp. gr., one part, and 
sulphuric acid of i'84 sp. gr. three parts, contained in iron 
pans. The skeins were stirred about in the acid bath for a 
few minutes,, removed to a grating above it, and some of 
the acid squeezed out with a suitable iron tool. The 
cotton, while still thoroughly wetted with acid, was trans- 
ferred to earthenware pots, in which it remained for forty- 
eight hours. The pots stood in cold water to prevent 
decomposition of their contents. At the end of two days 
the conversion of the cotton into guncotton was complete ; 
the skeins were removed from the pots, and as much as 
possible of the acid removed in centrifugal wringing 



machines. After centrifugalling, the skeins were drowned 
as rapidly as possible in a cascade of water, the object 
being to remove the rest of the free acid. The final puri- 
fication was effected by immersing the skeins for about 
three weeks in running water, boiling for a few minutes in 
an alkaline solution, and finally washing for a few days in 
flowing water. 

In all that concerned the actual process of nitration, 
Abel followed von Lenk, but instead of using skeins of long 
staple cotton, he introduced the use of cotton waste from 
the spinning mills, suitably cleaned ; and after the free acid 
had been removed in the preliminary drowning, the gun- 
cotton, still in the same physical condition as the cotton 
waste from which it had been produced, was reduced to a 
fine state of division in a beating-engine. The effect of 
this important modification was to remove the last traces 
of "free acid" and of unstable bodies, so that the pro- 
longed washing in cold water could be dispensed with, 
and at the same time, a much more stable product be 
obtained. 

Cotton fibre is of a tubular structure, and as long as 
these tubes exist in long lengths, the impurities in the 
interior of the tubes, derived from the evaporated juices of 
the cotton plant, and more or less affected by the nitration 
process, are extremely difficult of removal. Not only is 
the cotton in the form of long tubular fibres, but these 
fibres are themselves matted and entwined to such an 
extent that the former process of washing in running water 
even failed to remove impurities from amongst the bundles 
of fibre. 

The operation of pulping introduced by Abel breaks up 
both the bundles of fibre and the fibres themselves, reducing 
the latter to short lengths or destroying them altogether 
by crushing. In this fine state of division the removal of 
impurities is much more readily effected by washing. 

The manufacture of guncotton by the von Lenk-Abel 
process was commenced in this country about 1865. 
Foreign countries took it up in quick succession, and the 
process was the one universally followed for the next forty 
years. Some modifications of the nitration process were 
made towards the end of that period, in one case in the 
direction of dipping larger charges of cotton waste, and of 
allowing them to remain in the original acid mixture until 
nitration was completed, and then transferring the whole 
contents of the nitrating pan into the acid centrifugal ; in 
another case the nitration process was actually carried out 
in the centrifugal itself. 

In 1905, however, an entirely new system of nitration, 
hereafter referred to as the " displacement process," was 
invented by Messrs. Thomson, of the Royal Gunpowder 
Factory, and this process has been perfected and has 
entirely replaced the pot system of nitration there, and at 
Nobel's Explosives Factory at Ardeer, in Scotland. It is 
also being adopted at other factories both in this country 
and abroad. 

The nitration of the cotton waste is carried out in shallow 
circular earthenware pans. These pans are grouped 
together, and worked in sets of four. The bottom of the 
pan slopes downwards to a central hole, connected by suit- 
able pipes and cocks to a pipe supplying the nitrating acid, 
and to other pipes to which the waste acid is removed on 
completion of nitration. The pans are covered with 
aluminium hoods connected to an exhaust-pan, for carrying 
ofT fumes. 

Nitrating acid is then run in up to a definite mark, and a 
charge of 20 lb. of dry cotton waste is immersed in the 
acid in each pan in small quantities at a time. An aluminium 
fork is used for the purpose. When the charge of cotton 
waste has been dipped, perforated earthenware plates are 
placed on the top of it, to keep it all under the surface of 
the acid ; a film of cold water is run on to the surface of 
the plates, and serves as a seal to prevent fumes getting 
into the room, and the aluminium hoods are removed. 
The cotton waste remains soaking in the acid for two and 
a-half hours ; at the expiration of that time its conversion 
to guncotton is complete. The cock leading to the wastQ 



138 Improvements in Production and Application of Guncotton, &c. 



I CKtMICAL NbWS, 
1 March tg, igog 



acid pipe is then opened, and the waste acid allowed to 
flow away from the guncotton at a definite rate, whilst 
cold water is allowed to flow on to the top of the perforated 
plates at an equal rate. The water follows up the acid 
through the guncotton without any appreciable mixing of 
the water and the acid taking place, and when the whole 
of the acid has been displaced in this way, the water is 
allowed to drain away from the guncotton, which is then 
ready for the final purification process. This system of 
manufacture possesses many advantages over the systems 
which it is superseding. Foremost among them are : — 

1. Decreased cost of manufacture, due to the facts that 
for a given output very much less labour is required ; that 
the plant is both very cheap and very durable ; that no 
power is required to work it ; that less acid is lost in the 
washing processes ; and that, owing to the absence of 
fumes and spilt acid, the cost of maintenance of the 
buildings is reduced. 

2. Increased safety as far as personnel is concerned, 
because there is no escape or splashing about of acid, 
which in the old processes was a fruitful source of acid 
burns, and also because decompositions, which used to take 
place both in the digesting pots and in the acid centrifugals, 
with the consequent evolution of poisonous oxides of 
nitrogen, no longer occur. 

3. A better guncotton is obtained. It is freer from un- 
converted cotton, and as the whole of the nitration and 
preliminary washing operations are carried out in earthen- 
ware receptacles, it is freer from mineral impurities. 

4. An increased yield to the extent of about 7 per cent is 
realised. 

The manufacture of guncotton was not commenced at 
the Royal Gunpowder Factory, Waltham Abbey, until the 
year 1872. Shortly after that date an improvement was 
made in the purification process. It consisted in subjecting 
the guncotton, while still in the waste form, to a series of 
steam boilings in large wooden vats. In the early days of 
this process boilings of long duration were used throughout. 
Later, a system was introduced in which a large number 
of short boilings at the commencement was followed by a 
couple of final long boilings. With the introduction of the 
displacement process of nitration, a thorough investigation 
of the chemistry of the boiling process was undertaken at 
Waltham Abbey, and as a result it was ascertained that a 
more rapid purification was eff"ected by means of two long 
boilings, each of twelve hours duration, followed by a series 
of very much shorter ones. 

It is very probable that the displacement system of 
nitration is itself responsible for the reduction in the amount 
of boiling required to produce a stable guncotton. 
Although there is no appreciable amount of mixing taking 
place between the displacing water and the waste acid, 
still mixing at the surface of contact does occur to a slight 
extent, sufficient to produce a distinct rise of temperature. 
The zone of warm acid liquid produced passes very slowly 
through the whole of the guncotton, removing in its course 
various impurities. The purifying action of this liquid is 
no doubt due to the fact that it possesses strong oxidising 
and solvent properties. 

The pulping process introduced by Abel is still universally 
employed, and although its value from a purification point 
of view is no longer of such great importance now that 
guncotton is boiled, as it was in the early days of cold 
water washing, it is undoubtedly still of use in effecting a 
final purification of the guncotton. 

In the beating engine, the mechanical process of reducing 
the guncotton to a pulp is effected, but no actual removal 
of impurities takes place, because the water is not changed 
during the operation. The impurities still present in the 
guncotton at this stage are both mechanical and chemical. 
The mechanical impurities consist chiefly of particles of 
metal of various kinds, sand and fine grit, wood, and 
similar substances, introduced originally in the cotton 
waste and during the processes of manufacture. The 
chemical impurities are bodies produced by the action of 
the nitrating acid on bodies other than cellulose ; they are 



not entirely removed in the boiling process, but are set 
free in the pulping. To remove the mechanical impurities 
the guncotton pulp in a large volume of water, is at 
Waltham Abbey run from the beaters over flannel laid on 
long shallow troughs, the troughs having pockets with 
baffle plates at intervals. The rough surface of the flannel 
retains the fine particles of grit, &c., and the larger particles 
settle in the pockets or grit-traps. In the last pocket an 
electro-magnet is inserted to remove iron or steel particles, 
which may have escaped retention in the grit-traps. 

The guncotton thus freed from mechanical impurities 
runs into large oval iron tanks, called " poachers," where 
it receives several cold water washings. The contents of 
the poacher are agitated by means of a power-driven 
wooden paddle-wheel, and then allowed to settle. The 
washing water containing the impurities is drawn off from 
the surface of the guncotton by means of a large skimmer, 
in order that not only impurities in solution may be 
removed, but also any light solid impurities in suspension. 

The finally purified pulp is passed to a moulding machine, 
where it is lightly compressed to remove the bulk of the 
water, and converted into a form in which it can be easily 
handled. If intended for use in mines or torpedoes, or for 
demolition purposes, the lightly compressed shapes are 
submitted to heavy hydraulic pressure, converting them 
into dense hard blocks. 

The other high explosive of which I am to speak, viz., 
nitroglycerin, enters into the composition of many modern 
propellants. Nitroglycerin was discovered by Sobrero in 
1847, but it remained for a long time a chemical curiosity 
only. 

Alfred Nobel commenced its manufacture as a blasting 
agent, about 1868, for which purpose he absorbed nitro- 
glycerin with an infusorial earth, known as kieselguhi, and 
gave the compound the name of dynamite. But, prior to 
this, nitroglycerin had been made on a large scale in 
America, where it was frozen after manufacture, for pur- 
poses of transport, and used for blasting. 

Nitroglycerin is a liquid, and is a much more violent 
explosive than guncotton, and whereas the manufacture of 
guncotton is absolutely safe throughout, that of nitro» 
glycerin is dangerous. The risks attendant on the manu- 
facture of nitroglycerin are due to the facts that the tem- 
perature resulting from the chemical reaction is not so 
easily controlled and that nitroglycerin, being a liquid in- 
soluble in water, the processes after nitration have to be 
carried out with a substance not rendered inert, as gun- 
cotton is, by adm.ixture with water. For these reasons the 
nitration of glycerin in the early days of the production of 
nitroglycerin on a manufacturing scale was carried out in 
very small quantities. 

With the introduction of dynamite, the small pots used 
for the nitration of glycerin, standing in vessels full of ice- 
water, were replaced by lead tanks in which considerable 
quantities of glycerin, amounting to several hundred 
pounds, were nitrated at one operation. In these vessels 
the temperature was controlled by means of cold water 
circulating through lead coils fixed in the tank, and the 
whole contents of the tank were kept in agitation during 
the nitration by means of mechanical stirrers, or by com- 
pressed air escaping through small holes in lead pipes 
situated at the bottom of the nitrating vessel. On com- 
pletion of the nitration it was the practice in the early days 
to drown the whole of the charge of nitroglycerin and 
waste acid in a large bulk of water, from which the nitro- 
glycerin separated out, and was removed for subsequent 
purification by washing with alkaline solutions in lead 
tanks. This system entailed the loss of the waste acid, 
and was superseded by a process in which the nitroglycerin 
and waste acid were run from the nitrating vessel into 
another vessel termed a separator, and allowed to separate 
in it. The nitroglycerin, being lighter than the waste acid, 
came to the top and was run off into a third tank for 
preliminary purification consisting of several water 
washings. 

(To be continuad). 



Chemical News, » 
March 19, igog I 



A Ikaloids of Senecio latifolius. 



139 



PROCEEDINGS OF SOCIETIES. 

CHEMICAL SOCIETY. 
Ordinary Meeting, March /^th, igog. 

Sir William Ramsay, K.C.B., F.R.S., President, in the 
Chair. 

Messrs. A. G. C. Gwyer, R. E. Jackson, G. T. Morgan, 
W. N. Morley, C. S. Mummery, C. J. Regan, M. S. 
Salamon, and A. W. Stewart were formally admitted 
Fellows of the Society. 

Certificates were read for the first time in favour of 
Messrs. Harry Livsey, 54, Pemberton Street, Old Trafford, 
Manchester; Robert Cecil Owen, B.Sc, 89, Foregate 
Street, Chester ; Norman Scott Rudolf, M.Sc, Bangalore, 
India; Henry Llewellyn Smith, B.Sc, 23, EUingham 
Road, Shepherd's Bush, W. ; Arthur Percy Strohmenger, 
Bridgebank, Harrow-on-the-Hill ; George Bilderbeck 
Walker, Vale House, Trafalgar Road, Greenwich, S.E. 

Dr. Divers gave notice that, at the Annual General 
Meeting of the Society on March 25th next, he would 
move the adoption of a new By-law, to run as follows : — 

XIII. bis. — On Ascertaining the Will of the Society by 
means of Voting Papers. 

The President, either on his own motion or on a written 
requisition by the Council or by fifty Fellows, shall proceed 
to ascertain the will of the Society as to any suggested 
change in the By-laws or in the administration of these 
laws by the Council, by causing to be delivered, along 
with the Proceedings or separately, a notice to each Fellow 
of the change proposed, together with a voting paper upon 
it, to be filled in by the Fellow and returned to the Secre- 
taries not later than a prescribed date. After that date 
the results of the voting shall be counted by the Secretaries 
and two Scrutineers, appointed by the President, and be 
reported by him to a Council Meeting and to a General 
Meeting, upon which the Council shall proceed to act in 
accordance with the majority of votes, as being the ex- 
pression of the will of the majority. 

The President read the names of the Fellows recom- 
mended by the Council for election as Officers and as 
Ordinary Members of Council of the Society. 

A Ballot for the election of an Honorary and Foreign 
Member was held, and the President declared subse- 
quently that Prof. Dr. Georg Lunge, of Ziirich, had been 
unanimously elected. 

Of the following papers, those marked * were read : — 

•56. " The Action of Fuming Sulphuric Acid on Tri- 
phenylsilicol." By Geoffrey Martin and Frederic 
Stanley Kipping. 

Tetraphenylsilicane is decomposed by fuming sulphuric 
acid, giving sulphonic derivatives of benzene (Kipping and 
Lloyd, Trans., 1901, Ixxix., 449), and phenylbenzylethyl- 
propylsilicane is decomposed by sulphuric acid, the phenyl 
group being eliminated in the form of benzene (Kipping, 
Trans., 1907, xci., 209). 

These facts led the authors to doubt the existence of the 
" triphenylsilicoltrisulphonic acid " recently described by 
Ladenburg (B^r., 1907, xl., 2274; 1908, xli., 966), and a 
repetition of his experiments leads to the conclusion that 
his acid is not only a mixture, but also that it does not 
contain any appreciable quantity of triphenylsilicoltri- 
sulphonic acid. 

Even when triphenylsilicol is treated with fuming sul- 
phuric acid at - 10°, the greater part, if not the whole, of 
the silicol is decomposed and benzenesulphonic acid is 
formed, whereas at higher temperatures benzenedisulphonic 
acid is produced ; no compound containing silicon was 
isolated, but evidence pointing to the presence of diphenyl- 
siliconedisulphonic acid, SiO(C6H4'S03H)2, in the crude 
product was obtained. 



\-Menthylaminebenzenesulphonate,C6H^-S03H,Cioli2iN, 
forms colourless needles, melts at 223 — 226°, and is readily 
soluble in water, alcohol, or chloroform, but sparingly 
soluble in ethyl acetate. 

l-Menthylamine benzenedisiilphonate, 

C6H4(S03H)2,(C,oH2iN)2, 

melts at 212'', and is readily soluble in ethyl acetate, 
alcohol, or water, but insoluble, or nearly so, in ether. 

*57. " The Ignition-temperatures of Gases." By Harold 
Baily Dixon and Hubert Frank Coward. 

The temperature to which two gases must be heated in 
order that, when brought into contact, they will inflame 
immediately has been determined by passing an inflam- 
mable gas up a tube, terminating in a nozzle, fixed in the 
centre of a second tube conveying a current of air or 
oxygen, and electrically heated. Thus no reaction occurred 
during the preliminary heating of the gases. The tempera- 
ture of the gas 2 mm. below the nozzle was measured by 
means of a protected thermo-junction. 

The ignition-temperature of hydrogen thus obtained was 
constant, within 10°, under variation of the following 
circumstances : — 

1. The rates of flow of the gases, within wide limits. 

2. The size, material, and surface condition of the jet 
and of the walls of the furnace. 

3. The rate of heating of the furnace. 

4. The position of the thermo-junction, either inside or 
just outside the nozzle. 

The ignition-temperature was at first decreased some 
20° by increasing the diameter of the outer tube, but a 
limit was then reached when doubling the diameter pro- 
duced no further decrease. 

The ignition-temperature was raised 5° by working 
under half an atmosphere pressure, but decreased by 30" 
under a pressure of two atmospheres. 

The ignition-temperature of hydrogen in air is the same 
as in oxygen. 

The results obtained at atmospheric pressure are given 
in the following table. The paraffins and ammonia gave 
numbers varying with the rates of flow of the gases, as 
well as with the size of the furnace tube, so that their 
ignition temperatures are not so clearly defined as those 
of hydrogen, carbon monoxide, and the other gases. 

Ignition-temp, in oxygen. Ignition-temp, in air 



Gas. 
Hydrogen 
Carbon monoxide 

(moist) 

Cyanogen 

Ethylene 

Acetylene 
Hydrogen sulphide 

Methane 

Ethane 

Propane 

Ammonia 



Between. Mean. Between. Mean. 
580-590° 585° 580-590° 585" 



637-658 
803—818 
500—519 
400 — 440 
220—235 
556—700 
520 — 630 
490—570 
700 — 860 



650 644 — 658 651 

811 — — 

510 542—547 543 

428 (?) 406 — 440 429 

227 346—379 364 

— 650—750 — 

— 520—630 — 



Discussion. 

The President asked whether the temperature of 
ignition would not be aff"ected by varying the proportion of 
the gases ; for example, if the rate of flow be so adjusted 
as to diminish the relative amount of oxygen, while keeping 
that of the hydrogen constant. 

Professor Dixon replied that alteration of the proportion 
of the gases within wide limits had no effect on the ignition- 
temperature. 

*58. " r/<^ /I /^a/ou/so/ Senecio latifolius." By Henry 
Edgar Watt. 

The author has made a chemical examination of Senecio 
latifolius (N.O. Compositce), a poisonous plant which 
grows in South Africa, collected before flowering and also 
after flowering, and has isolated two new alkaloids of the 
formulae C18H27O8N and C18H25O7N respectively, for 



140 



Miscibility of Pyridine Bases with Water, 



, Chemical Nbws, 
I March 19, 1909 



which the names senecifoline and senecifolidine are pro- 
posed. The proportion of these substances present in the 
plant before flowering is equivalent to 1-20 per cent, whilst 
in the mature plant it only amounts to 0-49 per cent. 

Senecifoline crystallises in colourless, rhombic plates, 
which melt at 194 — 195°, and has [o]d + 28°8' ; it forms 
well-defined salts with nitric, hydrochloric, or hydriodic 
acids, and also an anrichloride. It can be decomposed by 
alkali into a hitherto undescribed dicarboxylic acid, 
CioHieOe, which it is proposed to name senecifolic acid, 
and a new base, C8H11O2N, for which the name senecifoli- 
nine is suggested. 

Senecifolidine crystallises in colourless, rhombic plates, 
which melt at 212", and has lujn - 13°56' ; it differs con- 
siderably from senecifoline in other physical respects, 
and forms salts corresponding with those mentioned above. 
Discussion. 

Dr. Watt stated, in reply to Dr. Bywaters, that Prof. 
Cushny had kindly undertaken to work out the pharma- 
cology of the alkaloids, and had already reported that one 
of them was poisonous to animals. 

*59. " An Interpretation of the Hantzch-Werner Hypo- 
thesis." By Martin Onslow Forster and Frederick 
Percy Dunn. 

From an investigation of the behaviour towards diazo- 
methane displayed by some typical oximes, the authors 
were led to suggest a possible explanation of the stereo- 
isomerism occurring in this group of compounds. 
Discussion. 

Dr. Flurscheim suggested that Dr. Forster's interesting 
hypothesis might perhaps also apply to the diazo-com- 
pounds formulated by Hantzsch as jjh- and a;j/j-isomerides. 

Dr. Morgan remarked that it would be of interest to 
know whether the supplementary valencies referred to by 
Dr. Forster were the ordinary valencies of oxygen and 
nitrogen indicated by the position of these elements in the 
periodic classification or the more elusive " Nebenvalenzen " 
postulated by Werner. 

On the ordinary theory of valency, the isomeric diazo- 
derivatives fall into line with this conception of the 
structure of the syn- and cM<i-oximes, for the former series 
of isomerides contains the necessary grouping with an 
element of variable valency (shown in heavy type) con- 
tiguous to the double linking — 

RN:NOK 

RNiNSOjK 

RN:N-CN. 

In the third case the required supplementary valencies 
could be obtained by a rearrangement of the cyanogen 
group. 

Mr. Baly asked Dr. Forster whether he had considered 
the expression — 

X Y 

\/ 
C 

l\ 
N=OH 

as the extreme phase arising from his formula. This would 
make the oxygen atom quadrivalent, but there appears to 
be no objection to this, seeing that Dr. Forster's own 
formula postulated a valency on the part of the oxygen 
supplemental to the two normal valencies. Dr. Forster's 
formula, moreover, would seem to require a supplemental 
valency on the part of the carbon in addition to the normal 
four. 

*6o. "The Triaso-group. Part IX. Transformation oj 
Cinnamoylazoimide into Cinnamenylcarbimide (cinnamenyl 
isocyanate)." By Martin Onslow Forster. 

The production of cinnamenylcarbimide when cinna- 
moylazoimide loses nitrogen in absence of water leads to 
the conclusion that other acyl azides owe their property of 
giving carbamates and carbamides with alcohols and 
amines respectively to intermediate formation of the 
respective c^rbimide, 



*6i. " Experiments on the Walden Inversion. II. The 
Interconversion of the Optically Active Mandelic Acids." 
By Alex. McKenzie and George William Clough. 

The preparation of rf-phenylchloroacetic acid was de- 
scribed. 

The following points have been investigated : action of 
water on / phenylchloroacetic acid, action oi water on 
salts of the optically active phenylchloroacetic acids, the 
displacement of chlorine in the active phenylchloroacetic 
acids by the amino-group, and the displacement of the 
amino-group in the active phenylaminoacetic acids by the 
hydroxyl group and by halogen groups. The inter-con- 
version of the active mandelic acids can be effected by a 
method different from that described previously, thus— 

rf-C6H5-CH(OH)C02H (byHNOi) /-C6H5-CH(NH2)-C02H 

Y(byPCl5) ^j\byNH40H) 

/-CeHsCHCl-COaH rf CeHsCHClCOaH 

Y(byNH40H) ^ ■^j^(byPCl5) 

rf-C6H5-CH(NH2)-C02H;^^^/-C6H5-CH(OH)C02H 

The striking feature in each one of these changes is the 
large amount of racemisation which always occurs. 

62. " Diazohydroxylamino-compounds and the Influence 
of Substituting Groups on the Stability of their Molecules." 
Bv Norman Leslie Gebhard and Herbert Bryan 
Thompson. 

Arylhydroxylamines react with diazonium salts to form 
diazohydroxylamino compounds or azohydroxyanilides, a 
class of substances which may be looked upon as hydroxyl 
derivatives of the diazoamino-compounds, in which the 
imino hydrogen atom of the latter is replaced by a hydroxyl 
group. The tautomeric phenomena shown by unsym- 
metrical diazoamino-compounds is not observed with the 
diazohydroxylamino-compounds. A series of these sub- 
stances, derived from ^-tolylhydroxylamine and various 
diazonium compounds, has been prepared with the object 
of examining the general properties of these little-known 
substances, and comparing the various compounds pre- 
pared with one another, with the view of determining the 
effect of substituting groups of various types and in different 
positions in the molecule on their general stability. The 
parent substance was benzenediazohydroxylamino-/> - 
toluene — 



CH, 



^N(0H)-N:N/ 






and a number of derivatives of this containing various 
substituting groups in the ring A have been prepared. 
The substituting groups used were methyl-, bromo-, nitro-, 
and carboxyethyl, whilst attempts were made to prepare 
the corresponding sulphonic acid and hydroxyl derivatives. 

63. " Tetraketopiperazine." Part II. By Alfred 
Theophilus de Mouilpied and Alexander Rule. 

The authors described the preparation and some of the 
reactions of tetraketopiperazine in a previous paper (Trans., 
1907, xci., 176). Attempts have since been made to reduce 
the compound to a piperine derivative, but without success. 
Phosphorus pentachloride and phenylcarbimide are without 
action on the tetraketone. 

The formation of coloured compounds during the pre- 
paration of the tetraketone had been noticed, and these 
are now found to be additive compounds of the sodium salt 
of tetraketopiperazine with sodium alcoholates. 

They vary in colour from deep indigo-blue to bright 
purple, and are easily decomposed by water, but remain 
unchanged in dry ether. 

64. " The Miscibility of the Pyridine Bases with Water 
and the Influence of a Critical-solution Point on the Shape 
of the Melting-point Curve." By Otto Flaschner. 

The problem of the connection between chemical con- 
stitution and mutual solubility of two liquids has been 
investigated in the case of the members of the pyridine and 



Chemical News, 
March 19, 1909 



Action of Carbon Dioxide on Nitrites 



141 



piperidine series combined with water. The width of the 
solubility ring for partly miscible liquids is taken as a 
comparable measure of the tniscibility, whilst the misci- 
bility of completely miscible pairs is defined by the width 
of that negative solubility ring which is obtained under a 
certain external influence, such as pressure or the solution 
of a third substance. The amount of this external action 
to be measured is that required to bring about under 
normal conditions the first appearance of two liquid phases. 
These considerations are illustrated by the miscibility of 
the three picolines and pipecolines with water. 

The influence of the neighbourhood of a critical-solution 
point on the shape of the melting-point curve was dis- 
cussed, and in the solutions of the zinc double salt of 
•y-picoline in the different aliphatic alcohols was found a 
convenient series of examples by means of which the 
analogy between the shape of a melting-point curve and 
that of an isotherm of a vapour in the neighbourhood of 
the critical point can be demonstrated. 

65. " The Preparation of Dichlorocarbamide." By 
Frederick Daniel Chattaway. 

When dichlorocarbamide is prepared by passing chlorine 
through a cooled concentrated aqueous solution of carb- 
imide, a yield of about 25 per cent of the theoretical can 
with care be obtained. Unless, however, the process is 
very rapidly carried out, with efficient cooling, the quantity 
which separates falls much below this maximum. The 
loss is mainly due to hydrolysis of the dichlorocarbamide 
under the influence of the hydrogen chloride formed in the 
substitution. If this hydrogen chloride is removed imme- 
diately it is formed by combining it with some basic sub- 
stance, hydrolysis is to a large extent prevented, and, if 
suitable quantities are used, over 75 per cent of the amount 
of dichlorocarbamide theoretically obtainable from the 
carbamide used can be isolated in a pure dry slate. 

Details of the procedure recommended, in which the 
hydrogen chloride is removed by zinc oxide, were 
described. 

66. " Thiotetrahydroquinazolines, Methylenecarbamides, 
Dicarbanilinomethylenediamines and their Homologues." 
By Alfred Senier and Frederick George Shepheard. 

The interaction of arylthiocarbimides with arylmethylene- 
diamines at temperatures from 150° to 200° results in the 
formation of cyclic compounds : cyclic carbamides and 
quinazolines. When the para-position in the aryl group of 
either the diamine or the thiocarbamide, or both of them, 
is occupied, thiotetrahydroquinazoline derivatives and a 
diarylthiocarbamide are formed. In all other instances, 
using thiocarbimides, and in all instances where the 
oxygen analogues, carbimides, are employed, the experi- 
ments being conducted at the temperatures mentioned, 
unstable cyclic metthylenecarbamides or thiocarbamides 
are probably formed, and at the same time a diarylcarb- 
amide or thiocarbamide. That these unstable cyclic carb- 
amides are actually formed, although they were identified 
only by the products of their hydrolysis, is rendered 
extremely probable by the fact that in two instances, 
employing a different reaction, namely, the substitution of 
methyleneaniline for a methylenediamine, the authors 
succeeded in isolating them and proving their instability. 

At the ordinary temperature, the course of the reactions 
is in agreement with previous experiments; carbanllino- or 
thiocarbanilinomethylenediamines or their homologues are 
always formed (Senier and Goodwin, Trans., 1901, Ixxix., 
254; 1902, Ixxxi., 283). 

67. " The Distillation of Butter Fat, Cocoannt Oil, and 
their Fatty Acids." By Kenneth Sommerville 
Caldwell and William Holdsworth Hurtley. 

The authors are of opinion that fats and fatty acids have 
no boiling-points in the vacuum of the cathode light, but 
that for any particular substance a temperature can be 
selected at which evaporation occurs at a speed convenient 
for fractional distillation. 

Butter fat, cocoanut oil, and their fatty acids were dis- 



tilled in the vacuum of the cathode light. The lowest 
fraction obtained from butter fat distilled with the bath 
temperature at 250 — 270° and inner thermometer at 187 — 
210°. Tributyrin distils rapidly with the bath temperature 
at 127° and inner thermometer at 107°. For this and other 
reasons, it is concluded that butter does not contain tri- 
butyrin. The iodine numbers yielded by the various 
fractions seem to indicate that there is little or no triolein 
in butter fat. Laurie acid forms at least 60 per cent of the 
fatty acids in cocoanut oil, whilst it could not. be detected 
in butter ; this method of distillation enabled the authors 
to detect with ease the presence of 10 per cent of cocoanut 
oil in butter. The presence of palmitic acid in cocoanut 
oil has been questioned by Ulzer (Ghent. Revue, 1899, 203), 
but the authors isolated several grms. of this acid from 
cocoanut oil. 

68. " Note on the Detection of White or Ordinary Phos- 
phorus in the Igniting Composition of Lucifer Matches." 
By Thomas Edward Thorpe. 

As the White Phosphorus Matches Prohibition Act, 
1908, will throw upon Officers of Customs and the Inspectors 
under the Factory and Workshop Act, 1901, the duty of 
sampling importations of matches and of materials in use 
in match factories, the author has examined the methods 
by which the presence of ordinary phosphorus in the 
igniting composition of lucifer matches containing phos- 
phorus sesquisulphide may be established, and he finds 
that the most direct and most certain test is to isolate the 
phosphorus as such , which is conveniently effected by gently 
heating the composition in a vacuum, when the phosphorus 
sublimes, and may be readily recognised by its physical 
characteristics. 

69. "Intramolecular Re-arrangement of the Diphenyl- 
amine Sulphoxides." (Preliminary Note). By Edward du 
Barry Barnett and Samuel Smiles. 

When the yellow tetranitro-, 3 : 9-dinitro-, and /sodinitro- 
diphenylamine sulphoxides are treated with suitable re- 
agents — for example, an alcoholic solution of hydrogen 
chloride — brick-red or chocolate coloured crystalline sub- 
stances are formed. According to the conditions of the 
reactions, the dark coloured compounds so obtained are 
either isomeric with the sulphoxides or differ from them by 
the content of a molecule of water. The evidence hitherto 
collected shows that these substances, although they are 
not of pronounced basic character, contain the ortho- 
quinonoid sulphonium structure, and this view is confirmed 
by the fact that the unsubstituted diphenylamine sulph- 
oxide is readily converted by aqueous acids into salts of 
phenazothionium. The depression of the basic properties 
in the nitro-derivatives is explained by the influence exerted 
on the quadrivalent sulphur by the acidic substituents. 

70. "A Crystalline Bleaching Powder." By Kennedy 
Joseph Previte Orton and William Jacob Jones. 

A basic hydrated compound of calcium chloride and 
calcium hypochlorite, which separates oncoolingmoderately 
concentrated (about 2N) solutions of bleaching powder, 
was described. This substance has been obtained in large 
prismatic crystals, the properties of which closely resemble 
those of bleaching powder. On the other hand, from very 
highly concentrated solutions of bleaching powder (about 
4N), a hydrated calcium hypochlorite separates at low 
temperatures. 

71. " The Action of Carbon Dioxide on Nitrites." By 
Ernest Robert Marle. 

The contradi