504 
when solutions of ordinary formaldehyde and potassium 
nitrate are allowed to remain in the dark. Now, as this 
acid is also produced on passing carbon dioxide through 
aqueous solutions of either potassium nitrate or potas- 
sium nitrite exposed to ultra-violet light, the requisite 
proof is furnished of the statement that the freshly 
synthesised formaldehyde must be beyond doubt 
activated formaldehyde. These experiments have led 
us to the conclusion that formhydroxamic acid marks 
the initial stage in the phytosynthesis of nitrogen com- 
pounds. This view is further substantiated by the fact 
that, on exposure to ultra-violet light, formhydroxamic 
acid rapidly reacts with activated formaldehyde to form 
various other products, many of a complex nature, 
whereas in the absence of light no such change occurs. 
In the course of these experiments, other facts of 
great importance have been noted. It has been found 
that by employing excess of nitrite no reducing sugars 
whatsoever are formed, but that if the activated formal- 
dehyde is in excess of that utilised by the nitrite, the 
presence of reducing sugars can be readily detected. 
These experiments prove that the synthesis of nitrogen 
compounds by the interaction of nitrites with activated 
formaldehyde takes precedence over the condensation 
of the latter to carbohydrates. In the plant, however}; 
as the amount of nitrogen actually fixed is small in 
comparison with the total carbon assimilated, both 
carbohydrate and protein formation take place simul- 
taneously. 
As regards the type of substances which have been 
classified up to the present, conclusive proof of the 
formation of a-amino acids has been obtained, and thus 
a definite intermediate stage in protein production has 
been reached. At least four distinct types of a-amino 
acids have so far been isolated in the form of their copper 
salts, and it is certain that at least one of these is a 
complex acid, possibly analogous to histidine. 
In addition to the synthesis of amino acids, nitrogen 
bases, such as methylamine, pyridine and piperidine, 
have been isolated. Substances of alkaloidal character 
are also formed in the reaction, but as yet we have been 
unable to separate any one alkaloid in sufficient quantity 
for detailed investigation. 
Another line of attack, at present in active progress, 
is the study of the action of ammonia on photochemically 
activated formaldehyde. Here again it has been 
ascertained that, whether one starts from carbon di- 
oxide and ammonia or from ordinary formaldehyde and 

NATURE 
[APRIL 14, 1923 
ammonia, identical products are obtained. Moreover, 
although under normal conditions interaction only 
occurs under the influence of light of very short wave- 
length, by employing ammoniacal copper solutions the 
reaction can be photocatalysed to take place in visible 
light. In all cases the presénce of methylamine, 
pyridine or piperidine, can again be recognised after 
comparatively short exposure to light, and by extending 
the period of illumination to several days the presence 
of alkaloids can also be experimentally confirmed. 
In this case it has been possible to isolate an indi- 
vidual alkaloid in sufficient quantity to enable numerous 
qualitative and physiological tests to be carried out. 
Despite the difficulties of identification of these sub- 
stances, the experimental evidence obtained would 
seem definitely to indicate that this photosynthetic 
alkaloid is coniine.14 
In conclusion, I would direct attention to some 
general deductions naturally arising from the work in 
hand. According to the views now put forward, it 
necessarily follows that, both in the case of the photo- 
synthesis of carbohydrates and also in that of the phyto- 
synthesis of nitrogen products, the whole centre of 
activity must be contained in the green leaf itself. As 
to the manner in which translocation from this point 
to other portions of the plant is brought about, it may 
be suggested that, as the synthesis of active hexoses 
takes place concurrently with the production of nitrogen 
compounds, the conditions are especially favourable for 
glucoside formation. In this way a method would be 
found for the easy removal of insoluble materials from 
the leaf. 
Finally, I would emphasise the point that in regard 
to the work being carried out by Prof. Baly and myself, 
our only claim is that we consider it by no means 
impossible to reproduce in the laboratory processes 
strictly analogous and directly comparable with those 
taking place in the plant. The chemistry of photo- 
synthesis is new and strange, and as such will un- 
doubtedly be viewed with a certain degree of scepticism, 
for the inherent conservative spirit among even 
scientific investigators tends to react against any new 
order of things. Photosynthesis is in the main the 
chemistry of one single substance—formaldehyde. The 
whole process is dependent on energy supplied from the 
sun and made available through the wonderful activity 
of the pigment chlorophyll. 
14 Baly, Heilbron, and Stern, Jour. Chem. Soc. (1923) 123, 185. 

Obituary. 
Lorp CARNARVON. 
\\/* much regret to record that Lord Carnarvon died 
at Cairo on April 5, from the effects of pneu- 
monia, supervening on erysipelas and blood-poisoning, 
the result of a bite on the cheek by an insect, presum- 
ably a mosquito. 
Lord Carnarvon was born on June 26, 1866, and was 
the son of the fourth Earl, whom he succeeded in 1890. 
He was educated at Eton and Trinity, Cambridge. 
He travelled extensively, won a reputation as a big- 
game shot, and was interested in the Turf. He was a 
great connoisseur and collector of illuminated books, 
manuscripts, and medals, as well as of antiquities of 
fine workmanship and small size. Of the last-named 
he had a remarkable and, in some respects, a unique 
NO. 2789, VOL. 111] 
1 

collection. It is, however, in connexion with the study 
of the history and antiquities of Egypt that Lord 
Carnarvon’s name will be handed down to posterity. 
In 1906 he, in association with Mr. Howard Carter, 
formerly inspector under the Egyptian Antiquities 
Department, began excavations, chiefly on the north 
side of the Assassif Valley near Der el Bahari, which 
resulted in the discovery, among other finds, of the 
tomb of the “ King’s Son” of Dynasty XVIII. in 1908 
and, in 1910, of a rich tomb of Dynasty XII. The 
results of these early excavations were embodied 
in Lord Carnarvon’s “Five Years’ Excavations in 
Thebes,” which appeared in 1912. 
After the War, Lord Carnarvon began excavations 
in the Valley of the Kings, a site which had rewarded 
