342 
but falls, The inability of insects to crawl up against the 
points of the hairs I have often tested in the most satisfactory 
manner” -(7yans. Linnean Society, vol. xii.). I have again 
and again released blue-bottle flies after they have been trapped, 
and have never yet found them act in any way that would 
suggest an intoxicating property in the secretion which they had 
fed upon—this is contrary to the information of ‘‘ W. C. M.,” 
who says :—‘* After feeding upon the secretion for two or three 
minutes they [the insects] become quite stupid, unsteady on 
their feet, &c.” To prevent the pitchers being injured by the 
large number of insects which are lured into them, we find it 
necessary at Kew to fill the mouths of the pitchers with cotton- 
wool ; this prevents the insects from falling in. Before this 
precaution was taken many of our finest pitchers were lost, 
owing to the decay which was caused by the rotten mass of 
insects which had accumulated in the bottom of the pitchers. 
“©W. C. M.” will be surprised to hear that, in spite of this 
cutting off of the supply of insects to the pitchers, the plants 
were in no way affected as regarded growth or vigour, but that 
the length and general health of the pitchers were more satis- 
factory after the insects were not allowed to enter them, than 
before. The concluding sentence in his remarks is rather start- 
ling, as, so far as investigations conducted by physiologists have 
gone hitherto, the Sarracenias are not known to be carnivorous. 
Mr. W. H. Gilburt, of the Quekett Microscopical Club, says :— 
“The pitchers contain fluid, but nothing corresponding to a 
digestive fluid has been detected in them ; so that, if the insects 
which perish in the pitcher are of any value to the plant and 
afford any nutriment, it must be simply by maceration, and the 
glands can be regarded as absorbent only.” Of course it may 
be said that Sarracenias would not have been constructed with 
what appears to be a view specially to catching imsects, if the 
insects were not to serve some useful purpose in the economy of 
the plant. Anyhow, at present it is only safe to say of Sarra- 
cenias that they allure and ultimately destroy insects, but we do 
not yet know that they obtain nourishment from them. Cer- 
tainly under cultivation there is abundance of evidence to prove 
that these, and in fact all those plants which are considered to 
be distinctly carnivorous, grow and thrive at least as well when 
insect food is not allowed them as when it is. 
Kew W. WATSON 
Colourless Chlorophyll 
In his elaborate ‘‘ Contributions to the Chemistry of Chloro- 
phyll” (Nature, vol. xxxii. p. 117), Mr. E. Schunck rightly 
observes that the explanation given by Mr. Tschirch for the 
curious fact discovered by Mr. Church is not based on sufficient 
proof. Indeed it could hardly be admitted that the action of 
metallic zinc is a process of reduction, since a similar result may 
be arrived at when zinc oxide is used instead of the metal. (A 
fact that I stated in 1869). 
But quite recently I have had the opportunity to convince myself 
that the reaction that takes place when a chlorophyll solution is 
treated by metallic zinc and an ovgante acid is of an utterly 
different nature. Through the agency of nascent hydrogen 
generated in the reaction, chlorophyll is actually reduced, the 
resulting substance being not of a green colour, but perfectly 
colourless, and presenting no traces of the characteristic chloro- 
phyll spectrum or fluorescence. It is only on coming in contact 
with the air that it gradually acquires both its green colour and 
specific optical properties. It is highly instructive to watch the 
phenomenon in a test-tube placed before the slit of a spectro- 
scope and observe the first appearance and subsequent growth 
of the dark bands, the colourless substance regaining in the 
mean while its original splendid emerald green. 
The physiological importance of this fact will be obvious to 
all botanists interested in the subject ; for my part I consider 
that the discovery of this colourless modification of chlorophyll 
brings additional proof in favour of an hypothesis that I pro- 
posed in 1875 concerning the chemical nature of chlorophyll— 
viz. that the green colour of this substance is due to the presence 
of iron in the state of a FeOFe,O, compound. Im fact, all the 
changes that this substance undergoes, its production, its de- 
struction, the action of acids, of metallic zine and zinc oxide, 
might be easily accounted for by admitting this simple and very 
plausible hypothesis. 
But whatever may be the ultimate fate of this “ provisional” 
hypothesis, the fact just stated will lose nothing of its import- 
ance. Its chief interest lies in the establishment of the existence 
of a colourless substance, acquiring by oxidation all the optical 
NATURE 
[August 13, 1885 
properties of chlorophyll. It is evident that chlorophyll is 
generated in this case by a process similar to that which takes 
place in the living plant. (The existence of such a substance 
has been often announced, but continues to be a subject of 
doubt). At the same time we may see the reason why, 
admitting that chlorophyll undergoes a process of reduction 
when CO, is dissociated through the agency of light (this 
supposition is highly probable), this transformation may not 
be attended by a visible change of its colouy, and other optical 
properties—the produce of reduction being colourless and having 
no dark lines in the spectrum. However, the change of colour 
that M. Sachs observed in a great number of leaves on exposing 
them to direct sunlight, and which is generally attributed to a 
migration of the chlorophyll grains, might, partly at least, be 
due to this process of reduction. C. TIMIRIAZEFF 
Moscow, July 15 
July Meteors 
BETWEEN July 8 and 14, 111 shooting stars were recorded 
here in 11} hours of observation. The paths of these, repro- 
duced upon an 18-inch celestial globe, enabled me to fix the 
radiant points of 12 showers with considerable distinctness : — 
No. et eras Notes. 
I ... 13-14 .... 11+48 Meteors long, swift with streaks. 
2... 8-13 ... 245+52 Slow, yellow, max. July 8. 
3... 13-14 ... 255+37 Slow, faint, near r Herculis. 
4... 9-13 ... 265+63 Slow, faint, near ¢ Draconis. 
5... 9-14 ... 271+21 Slow, faint. In Cerberus. 
6 ... 9-13 ... 280-14 Very slow, long paths. 
7... 13-14 ... 285+42 Very swift and short, near a Lyre. 
8... 9-13 ... 289+ 31 Swift, faint, near y Lyrze. 
9... 8-13 ... 290+60 Slow, bright, near o Draconis. 
Io... 8-13 ... 303+24 Swift. In Vulpecula. q 
II ... 13-14 ... 314+47 Veryswift, short, bright, nearaCygni. — 
12... 9-14 ... 329+36 Swift, reddish streaks. S. of Lacerta. 
Nos. 1, 7, 8, 9, 11, and 12 were well observed by Zezioli in 
1867-68, and form: Nos. 93, 90, 88, 89, 99, and 98 of the cata- 
logue of radiants derived by Schiaparelli from his observations. 
Generally the meteors observed here during the past month 
were small, but three were estimated as bright as Jupiter. The 
first of these appeared on July 8 at 12h. 1m., shooting rapidly 
along a course of 27 degrees a little west of ¢, », @ Draconis. 
It left a brilliant streak, enabling the path to be very accurately 
noted. This meteor belonged to the radiant at 11° + 48°, and 
soon afterwards, at 12h. rom., another fine one was seen pur- — 
suing a greatly foreshortened path near 5 Draconis and throwing 
off a dense train of yellowish sparks. Its motion and appear- 
ance prove it to have been a Draconid and a member of the dis- 
play from 290° + 60°. On July 9, at 13h. 50m., I recorded a 
fine meteor shooting upwards, just east of Altair, froma centre at ~ 
304° —15° near aand 8 Capricorni ; but I have not included this 
position in the list, as I only saw one other shooting star with a 
conformable direction during the period included by my 
observations. 
On July 31 a few fine and early members of the August 
Perseids were seen, and on August I, between 9h. 45m. and 
gh. 50m., I noted three others, two of which were unusually 
brilliant, and projected vivid streaks upon their long, graceful 
flights through the Milky Way west of Aquila, This con- 
spicuous and early appearance of the Perseids would seem to 
predicate a bright maximum on the night of August Io. 
Bristol, August 2 W. F. DENNING 
The August Meteors 
Last night at 9.32 a brilliant meteor crossed Cassiopeia’s — 
Chair from W. to E. parallel to the horizon, Its trail was 
visible for twenty-six seconds after the bursting of the meteor. 
During a five mile walk, lighted by many meteors, the summer 
lightning incessantly flashed from the northern horizon, but its 
brightness was never comparable to that of this meteor. It re- 
sembled most a magnesium rocket in the Crystal Palace fireworks. 
But even this comparison is hardly adequate. 
Chatham, August 12 y HH, Be JigPe 
A Possible Windfall for Science 
Is not the better course for immediate action that the depart- 
ments in England and the United States should first combine ? 
