FEBRUARY II, 1897 ] 
ied TURE: a4 
LETTERS TO THE EDITOR. 
[Zhe Editor does not hold himself responsible for opinions ex- 
pressed by his correspondents. Neither can he undertake 
to return, or to correspond with the writers of, rejected 
manuscripts intended for this or any other part of NATURE. 
No notice ts taken of anonymous communications. ] 
The Direct Cynthesis of Optically Active Proteid- 
like Substances 
In a recent communication to the Royal Society (Proceedings, 
No. 364, lx. 337-349), of which an abstract has appeared in 
Nature, Dr. Pickering describes experiments he has made—in 
extension of those carried out by Grimaux several yearsago—on 
the synthesis of certain proteid-like substances: the substances 
were obtained by heating amido-acids, such as par- and meta-mi- 
dobenzoic acid and tyrosine, with amides, such as alloxan, biuret 
and xanthine, in presence of a dehydrating agent, or even by 
heating the amido-acid alone with the dehydrating agent. The 
substances so produced are said to be all soluble in warm water, 
forming opalescent /evorotatory solutions, the values given for 
a, varying between —38 and —52; but itis not clear what 
is meant by this, as the symbol ap is commonly used to denote 
the observed rotatory power, and is meaningless unless the 
strength of solution, &c., be stated, from which the specific 
rotatory power can be deduced. 
Dr. Pickering does not appear to be aware that if his state- 
ments are correct, he has made a discovery of a startling 
character, altogether remarkable in the light of our present 
knowledge. In all cases hitherto studied—not excluding nitrogen 
compounds (e.g. artificial conine)—as Pasteur foresaw would 
doubtless be the case, optically active substances are never 
directly produced; the synthetic product is always inactive. 
For example, when tartaric acid is synthesised, a mixture is ob- 
tained consisting of mesotartaric acid—the internally compen- 
sated modification—and racemic acid, this latter being resolv- 
able into equal quantities of the two equally but oppositely active 
tartaric acids. 
It is therefore desirable that Dr. Pickering should state 
exactly what is the evidence on which he relies as proving that 
the substances he has obtained are possessed of optical activity. 
Having reason to think that nitrogen may manifest peculiarities 
hitherto unsuspected, I await such information with im- 
patience. 
Dr. Pickering speaks of having obtained several of the sub- 
stances in translucent yellowish plates. What are we to under- 
stand from this? It would be interesting if we knew whether 
the substances are crystalline. 
Grimaux, who has discussed coagulation phenomena in a 
thoroughly scientific manner, has pointed out that the proteids 
do not differ as colloids in any essential manner from mineral 
and other colloids such as Graham investigated ; and it is per- 
haps, therefore, fair to question whether the production of intra- 
vascular coagulation, on which Dr. Pickering lays stress, is so 
significant a property as he supposes as indicating affinity with 
true proteids. |The substances he has obtained cannot well, 
from the chemical point of view, bear any real structural relation- 
ship to natural proteid substances. 
HENRY E. ARMSTRONG. 
Carbon in Bright-Line Stars. 
Dr. Hucerns should verify his references; it has taken me 
some considerable time to find the article he erroneously states 
to be contained in vol. xlviii. of NATURE. 
That article was an attempt to summarise a good deal of 
work I had communicated to the Royal Society, with all 
necessary details. 
To avoid the necessity of giving these details in the article, I 
distinctly stated that ‘* in the Bakerian lecture for 1888 I gave a 
complete discussion of the spectra of bright-line stars,” and 
referred to the ‘*bright fluting of carbon which extends from 
468 to 474.” 
The details were thus stated in my communications to the 
Royal Society :—‘* The bright band, with its maximum at 468, 
is the bright carbon fluting commencing at 474, and extending 
towards the blue with its maximum at 468, as photographed at 
Kensington” (Roy. Soc. Proc., vol. xliv. p. 37, March 1888). 
“Tt is necessary to state that the maximum luminosity of 
he blue band, under some conditions, is at about 468. As I 
have so often had occasion to refer to this, I here reproduce one 
NO. 1424, VOL. 55 | 
of the many photographs of the spectra of carbon compounds 
which show it” (Roy. Soc. Proc., vol. xlv. p. 169, November 1888). 
In a paper communicated to the Royal Society, on November 
9, 1889, in which this blue band of carbon is very frequently 
referred to, both in connection with comets and bright-line stars, 
its position is throughout defined by the figures 468-474, whether 
the brightest part was at 468 or 474. I had previously shown that 
the maximum might be at either wave-length in the spectra of 
different comets, and my earlier papers had sufficiently stated 
that in the case of bright-line stars the modified band, with the 
maximum at 468, was in question. Thus in comparing the 
spectra of comets and bright-line stars, ‘‘ 468-474” was used as 
a short title for the blue band, whether in flame, comet, or star, 
and this applied also to the new observations which were recorded 
at the same time, showing the coincidence of the star band with 
the spirit-flame band. With the instrument employed, the 
whole group in’ the flame spectrum appears as little more than 
a broad line; but that the previously noted shift of the maximum 
to 468 was simply regarded as ancient history, is shown by 
sketches in the Solar Physics Observatory note-books, which I 
shall be glad to show Dr. Huggins, if he cares to see them. 
I certainly see no reason to withdraw my assistants’ observa- 
tions of the blue band, but in the article which has given rise to 
this discussion (NATURE, January 28, 1897) I regarded them as 
superseded, as most of Dr. Huggins’ observations have been, by 
recent observations, made with much greater optical means. I 
am not aware that it is customary to formally withdraw observa- 
tions which have simply been superseded with the help of im- 
proved instruments. 
I retained the observations of the green fluting, however, for 
reasons sufficiently stated in my article. 
Dr. Huggins apparently objects to my statement that Prof. 
Campbell does not discuss the origins of the lines and bands 
which he has measured, but it will be seen by his quotation from 
Prof. Campbell’s paper that my statement is amply justified. 
Prof. Campbell makes only a general reference to the question 
of origins, and has only compared with ‘‘ well-known artificial 
spectra.” It is not quite clear what is meant by ‘‘ well-known” 
spectra, but presumably it is the published tables of lines seen 
in the arc and spark spectra of the more familiar substances 
which are meant ; these lines, however, would not be the only 
ones to be expected under the exceptional conditions which 
exist in a bright-line star. The experimental work on the blue 
band of carbon is only one indication of the necessity for 
observing terrestrial spectra under special conditions for such an 
investigation. It is certainly impossible that the resources of a 
comparatively young institution like the Lick Observatory can 
be sufficient to cope with this inquiry into origins. 
With reference to Prof. Vogel’s observations of the varying 
position of the maximum of the carbon band, I can only repeat 
the statement of my regret that I had forgotten them when my 
paper of 1888 was written. I have nowhere stated that this 
observer ascribed the blue band in the bright-line stars to carbon, 
but it is certainly strange he has not done so, since a similar band 
at about the same wave-length in the spectrum of comets was ex- 
perimentally demonstrated by him to be probably due to carbon. 
It would appear that if Dr. Huggins had done me the honour 
of reading my communications to the Royal Society, his letter 
would not have been written. J. Norman LOCKYER. 
February 9. 
Origin of the Cultivated Cineraria. 
Tue discussion in these pages, rather more than a year and a 
half ago, upon the origin of the ‘‘ Cultivated Cineraria,” by Mr. 
W. T. Thiselton-Dyer, Mr. W. Bateson and others, was pro- 
ductive of very considerable interest. It raised in my mind the 
idea of producing some living evidence on the question ; but the 
unfortunate position is, that certain kinds required for the pur- 
pose are not in cultivation. I venture to appeal, therefore, to 
the readers of NATURE, who were interested in the discussion, 
and who may visit or live in the Canaries or Madeira, to be so 
good as to send me any seed they may be able to obtain. It is 
desirable to have seeds of all the herbaceous species of Seveczo, 
without exception. S. Zzss¢laginis I consider important, 
whatever the facts of origin may have been, and it is necessary 
to have a new stock of S. crwentus. I have already used the 
material at command, and have made a variety of crosses among 
four distinct types. The set first in flower was exhibited, on 
account of its showy features, at a recent meeting of the Royal 
