BEE-spoke-data/bees-v0 huggingface dataset:
The indicators were scarcely in place when they began to move. Sometimes they seemed to precipitate themselves towards the door, and stop for a moment, sometimes they were repelled with the same rapidity and held themselves in the air as much as one or two inches out of the perpendicular. The amount of motion appeared to be proportionate to the number of bees fanning. Sometimes there was less movement but they were never entirely stopped.
This experiment therefore demonstrates the existence of a current of air at the door of the hive: It shows that the air corrupted by the bees is at once replaced by external air, thus explaining the purity which we had previously noted.
It may possibly be objected that it is the custom of some beekeepers to close the doors of their hives during winter, apparently without harm. Assuredly if, by this method, entry of air were completely prevented it would be obvious that the bees could do without it. But this practice is only followed by skeppists and skeps are very difficult to close entirely as the air can penetrate through their joints.
For the rest we can affirm nothing of the winter as we only made a single experiment, though it certainly seemed sufficient to set our minds at rest on this point. It was again to Burnens that we entrusted the care of the experiment. He had by this time left us and sent the following letter on the subject:
I have just carried out, at the request of M. Senebler, the experiment which we made in the summer.
I chose for it a skep which was well populated, and one in which the bees seemed to be full of life and activity. After having fixed the edge of the skep to its floor, I placed through the top a fairly strong wire ending in a hook from which I suspended a loop made in the end of a hair. This carried a small square of the thinnest paper I could find, which was placed level with the door of the hive and at a distance of about an ineh from it.
As soon as the apparatus was in position, I noticed that my indicator began to move. To measure the movement I had placed at the junction of the hair and the paper a small horizontal rule graduated in lignes!* of the Paris foot. The paper moved backwards and forwards a number of times, and the greatest movements were an inch out of the perpendicular.
I tried putting the paper at a great distance from the opening, but the oscillations no longer took place, and the apparatus remained motionless.
Following your suggestion I made an opening in the upper part of the skep and ran in some honey. Very soon afterwards the bees started humming. Then the hum became louder, and several bees emerged. I watched the apparatus carefully, and saw that the movement of the paper was more frequent than before the introduction of the honey, and that it had a greater intensity: for when I fixed the hair fifteen lignes from the entrance, the paper was definitely moved to and fro several times. I endeavored to see whether the movement would take place at a greater distance, but the paper remained motionless.
All that remains is for me to report on the temperature. I had an alcohol thermometer which registered a shade temperature of 5%*R. (just over 43%*F). There was bright sunshine, and the experiment was made at 3 p. m.
If you wish for any further work be so good as to tell me of it, and I will fulfill your bebests with the greatest pleasure.
Your most humble and obedient servant,
F. BURNENS.
PART. V.
Phoofs Taken From the Results of a Mechanical Ventilator.
The preceding experiments left me in no doubt as to the object of ventilation. One could no longer hold the theory that the air was produced by chemical changes within the hive. I had shown that the used air could not
1*The twelfth part of an inch.
by its own change in weight set up the ventilation which is so essential to the bees. However not daring to trust entirely to my own judgment I wished again to consult M. Saussure before establishing an hypothesis which in many ways is of interest to scientists. This learned man was interested in the results of my experiments and being struck by the originality of the means employed by Nature to preserve bees from a certain death, suggested to me a test which would do away with all doubts on the matter.
He saw only one way of deciding whether the renewal of air in the hives could be attributed to natural ventilation, and this was to imitate the movements of bees by a mechanical action under conditions similar to those of an ordinary hive, all other possible sources of ventilation being cut off. He suggested that I should use a mechanical ventilator, the wings of which would vibrate at a speed fast enough to reproduce the movement of fanning bees. One of my friends15, a skillful mechanic and clever scientist, helped me to make this instrument, and assisted also in the various experiments for which it was destined.
In place of a number of small ventilators we constructed a tin windmill having eighteen wings. We adapted this to fit a large cylindrical vessel of which the capacity was increased by a super on which it was solidly fastened. An opening in the super of suitable size, which could be completely closed, served to introduce a candle into the bell jar. The ventilator was placed above the super and fixed in place. On one side of this box we had arranged another opening.
This part of the apparatus communicated with the upper vessel, but was arranged to prevent a direct draught, so that the ventilator should not itself blow out the candle. We suspended light substances in front of the opening of the box, and started with the following experiment in which the mill was not put into action.
FIRST Experiment.
We introduced a candle into the bell jar, the hole corresponding to the door of the hive being left open. The flame did not long maintain its first brilliancy. It soon diminished, and at the end of 8 mins. went out, although the capacity of the vessel was about 3228 cubic ins. The upper part of the bell jar was warm, and the indicators gave no sign of any current of air.
After having renewed the air which had been consumed, we repeated the experiment. The candle went out after the same length of time, showing that one opening only is not sufficient for circulation of air, unless it is put in motion by some outside agency.
Having again renewed the air of the vessel, we replaced the candle, and hung several indicators near the door. When these preparations were madewe started the ventilator. At once two currents of air were established: the indicators showed this clearly, swinging to and from the door, and the brilliancy of the light did not diminish at all during the course of the experiment, which could be prolonged indefinitely. A thermometer placed at the lower part of the apparatus registered 40"R. (122degF.), and the temperature in the upper part was evidently higher.
I wished to see whether my ventilator would provide enough air for two lighted candles. They burnt for 15 minutes and then went out together. In another test where the mill had not been started, they burned for 3 minutes only.
Fifti Experiment.
We tried increasing the number of openings in the side of the box, but were not successful. One of the two candles went out at the end of 8 minutes. The other kept alight as long as the ventilator was in motion. I had therefore not obtained a stronger air current by multiplying the openings. These experiments show that in a place with an opening only on one side, air can renew itself when there is some mechanical cause tending to displace it, and this seems to confirm our conjecture on the effect which the fanning of bees has on the hive.
ARTICLE VI.
Immediate Causes of Ventilation.
We shall misconstrue Nature if we suppose that the real objects of any given actions are always those which appear on the surface. This line of thought, which is capable of great development, is one of those which best show that invisible power which governs the universe. The bees in beating the air with their wings little realize the object which they achieve. Perhaps some simple desire or need makes itself felt, and instinct prompts them to fan their wings which seem to have been given them for flying only. This is without doubt a natural reaction to the stimulus of some particular sensation, for one cannot credit them with the knowledge which would lead us to act were we in an analogous position. Nevertheless it is interesting to note the characteristics with which Nature endows them; lower orders though they be, since they achieve the end which they set out to accomplish.
The first idea which occurs to us is that the bees do not fan except to procure a sensation of freshness, and an experiment will easily convince us that this motive may be one of the actual causes of fanning. We opened the shutter of a glazed hive: the sun's rays beat on the combs covered with bees. Soon those which first felt the influence of the heat started to hum, while those still in the shade remained quiet. An observation which one can make any day confirms the result of this experiment: the cluster of
bees one sees in front of the hive during the summer, feeling the heat of the sun, fan with the greatest energy, but if an intervening body shade a part of the cluster, the fanning ceases in the shaded part, while it continues in that which is in the sun.
The same fact may be noticed with insects similar to bees. The velvet coated bumble bees whose nest we kept on a window still, ordinarily became very active when the sun heated the box which held them, and all beat their wings, making a loud humming.
Sometimes one hears the same noise in nests of wasps or hornets. Thus it seems a constant law that heat will cause bees or other insects to fan.
But the remarkable point about bees is that they fan in the depth of winter, and that this noise is often the sign by which one tells that they are alive during that season. Heat is therefore only a secondary cause which in summer augments this habit of the bees. It is necessary to seek other causes. We tried surrounding bees with various obnoxious gases and found that several of these stimulated them to fan. We separated a number of bees from their hive, leaving them with some honey, and then placed some cotton wool soaked in methylated spirit near to them while they took their food. The wool had to be placed quite close to their heads before they noticed it, but then the effect was striking. The bees at once moved away, returning again shortly to the honey. As soon as they had come back we recommenced the experiment. They moved away once more, but this time without entirely rolling up their tongues, contenting themselves with beating their wings while feeding. Several times however the insects too close to the disagreeable odours moved away immediately and took to flight. Sometimes a bee turned her back to the honey, fanned until the odour was diminished, and then turned back to partake again of the repast we had provided.
These experiments succeeded best at the door of the hive, as the bees, held by the double attraction of honey and their home, were less disposed to escape by flight from the smell with which we were testing them. The humble bees, of which we have already spoken, act in the same manner when confronted by harmful odours, but a point which is very remarkable and emphasizes to a certain extent the importance of fanning, is that the drones and queens, though very sensitive to strong smells, do not know how to preserve themselves as do the workers.
Ventilation is therefore one of the labours of the hive undertaken only by the workers. The Almighty, in assigning to these insects a dwelling place into which air could only penetrate with difficulty, also gave them a means to overcome the sad effects which might result from the alteration of their atmosphere.
Of all the animal world the bees are perhaps the only creatures to which the care of so important a function is given, and incidentally this indicates the perfection of their organisation. An indirect consequence of this ventilation is the high temperature which bees sustain without effort in their hives. It results from their breathing as is the case with all other living beings. This heat, which one writer has attributed to the fermentation of honey, is certainly derived from the gathering together of a number of bees in the same place. It is so absolutely essential to them and their brood that it should be independent of the temperature of the outside air.
The very existence of the bees is therefore in direct dependence on the continuity of their fanning. Though called to so many different labours, each of these insects must occupy itself constantly in the duty of maintaining the air at the necessary degree of purity. This function, exercised by a number of individuals each in their turn, does not exempt any of them from the other work of the hive which has to be performed.
Thus the social organisation of these insects permits them to fulfill in turn the different functions imposed on the entire population.
## Chapter 12although a custom very prevalent among the country people seems to support a contrary opinion; I allude to the practice of striking a sonorous instrument, at the time of issue of a swarm, to prevent it from flying away; but in compensation, how great is the perfection of their organ of sight! How easily a bee recognizes her habitation amidst an apary of numerous boxes all similar to its own! She returns to it in a straight line and with extreme speed, which indicates that she distinguishes it from the others from afar by marks escaping our notice. The bee departs and flies straight to the most flowery field; having ascertained her course, she is seen traversing it by a path as direct as the flight of a bullet escaping from the barrel of a musket: her harvest being made, she rises aloft to recognize her hive and returns with the rapidity of lightning. (Since Huber wrote the above, it has been ascertained that the so-called beeline is more or less wavy, probably owing to the currents of air and the breeze. Translator).
Their sense of feeling is perhaps still more admirable, it is substituted for, and completely supplies the want of sight within the hive: the bee constructs her combs in darkness, pours her honey into the magazines, feeds the young, judges of their age and necessities, recognizes her queen, all by means of the antennae, the shape of which are much less adapted for _knowledge_ than our hands; shall we not therefore grant to this sense modifications and perfections unknown to the touch of man? Had we but two fingers to measure and compare so many divers things, what subtility would they not require to perform the same service?16
The sense of taste is perhaps the least perfect of all the senses of the bee; for this sense in general admits of selection in its object, but contrary to the received opinion the bee certainly displays little choice in the honey that it collects. Plants whose odor and savor appear to us most disagreeable do not repulse them. Poisonous flowers are not excluded from her choice, and it is said that the honey harvested in certain provinces of America is a rather violent poison; aside from this, bees do not despise the secretions of aphides under the form of honeydew, in spite of the impurity of its origin; we see them even quite tolerant concerning the quality of the water which they drink; that of ponds and of the foulest ditches is seemingly preferred to the most limpid stream and to dew itself.
Nothing therefore is more unequal than the quality of honey: that of one district does not have similar flavor to that of another; that of spring is unlike that of autumn; the honey of one hive does not always resemble that of the hive adjoining.
Thus it is true that the bee does not select her food; but if she is not particular as to the quality of the honey, she is not indifferent as to the quantity contained in flowers. They constantly resort where most is to be found; they issue from their hive much less in regard to the temperature than according to their expectation of a more plentiful or scanty harvest. When the basswood (tilia) or buckwheat are in bloom, they brave the rain, they depart before sunrise, and return later than ordinary; but this effervescence relaxes as soon as the flowers fade, and when the scythe has cut
## 6 On the senses of bees, especially of smelj.
down those which adorned the meadows, the bees remain in the hive, however brilliant the sunshine. To what shall we ascribe the knowledge of the greater or less abundance of honey in the flowers of the country which bees appear to possess, without leaving their home? Does one sense, more subtle than the others, that of smell, warn them of it?
There are odors repugnant to bees; others attract them; the smoke of tobacco and every other kind of smoke displease them. Human industry turns to its benefit their aversion as well as their liking; but it is satisfied with reaching the desired aim and does not invade the domain of philosophical inquiry.
Led by other motives, we will endeavor to find how different odors affect the bees, to what degree they are attracted by some and repulsed by others; this is within our reach; perhaps some day the growth of progress will permit us to go beyond.
Of all odorous substances, honey is that which most powerfully attracts bees; other odors have the same faculty perhaps only as far as they suggest to them the presence of a liquid which seems so valuable to them.
To ascertain whether it was the odor of honey and not the sight of flowers only which apprises bees of its presence, we must hide this substance where their eyes could not see it; for this purpose, we first placed honey near the apiary, in a window, where the shutters almost closed still allowed their passage if they chose; in less than a quarter of an hour, four bees, a butterfly and some house-flies insinuated themselves between the shutter and the window, and we found them feeding on it. Although this observation was sufficiently conclusive, I wished it better confirmed: we took boxes of different sizes, colors and forms, we adjusted to them small card valves corresponding with apertures in their covers; honey being put into them, they were placed two hundred paces from my apiary.
In half an hour bees were seen arriving, they carefully inspected the boxes, and soon discovering the openings through which they could enter we saw them press against the valves and reach the honey.
One may thence judge of the extreme delicacy of smelling of these insects; not only was the honey quite concealed from view, but its emanations could not be much diffused, since it was covered and disguised in the experiment.
Flowers frequently exhibit an organization resembling our valves: the nectery of several classes is situated at the bottom of a tube, enclosed or concealed by the petals; nevertheless the bees find it; but its instinct, less refined than that of the bumblebee (Bremus), affords less resource; the latter, when unable to penetrate the flowers by their natural cavity, knows how to make an aperture at the base of the corolla, or even of the calyx, to insert its probocsis at the place where nature has located the reservoir of honey; by means of this straegem and the length of its tongue, the bumblebee can obtain honey where the domestic bee would reach it with great difficulty. From the difference of the honey produced by these two insects, one might conjecture that they do not harvest it from the same flowers.
The honeybee, however, is as much attracted by the honey of the bumblebee as by her own. In a time of scarcity, we have seen them pillage,a nest of bumblebees which had been placed in an open box near an apiary; they had taken almost entire possession of it: a few bumblebees, remaining in spite of the disaster to the nest, still repaired to the fields and brought back the surplus of their needs to their ancient asylum; but the plundering bees, trailing them, accompanied them home and never quitted them until having obtained the fruits of their harvest; they licked them, held out their trunks, surrounded them and did not release them until they had obtained the saccharine fluid of which they were the depositaries: they did not try to kill the insect which thus afforded them their repeat; the sting was never unsheathed, and the bumblebee itself was accustomed to these exacerbations, it yielded its honey and resumed its flight: this new-fashioned domestic economy lasted above three weeks; wasps, attracted by the same cause, did not become so familiar with the original propriators of the nest; at night the bumblebees remained alone; they finally disappeared and the parasites did not return.
We have been assured that the same scene happens between robber bees and those of weak hives, which is less astonishing.
Not only have the bees a very acute sense of smell, but to this advantage is added the recollection of sensations; here is an example. Honey had been placed in a window in autumn, bees came to it in multitudes; the honey was removed and the shutters closed during the winter; but when opened again, on the return of spring, the bees came back, though no honey was there; doubtless they remembered that some had been there before; thus an interval of several months did not obliterate the impression received.
Let us now seek the site or the organ of this sense, whose existence has been so well proved.
Nostrils have not yet been recognized in insects, nor do we know in what part of the body these, or any organs corresponding to them are placed, in this class of beings. Probably odors reach the sensorium, by a mechanism similar to the one given to us; that is, the air is introduced into some opening at the termination of the olfactory nerves; hence we must ascertain whether the stigmata do not perform this function, whether the organ which we seek is situated in the head or in some other part of the body.
First Experiment.
A pencil dipped in turpentine, one of the substances most formidable to insects, was presented successfully to all parts of the body of a bee, but whether it was brought to the abdomen, the thorax, the head, or the stigmata of the thorax, the bee which was busy eating did not seem to be in the least affected.
From the uselessness of the first test, we concluded that it was necessary to bring the pencil successively to all parts of the head: so we took a very fine pencil, to avoid touching more than one spot each time. The bee, busy with her meal, held her trunk protruding forward; we brought the pencil near the eyes, the antennae, the trunk, in valn; it was otherwise when we placed it near the cavity of the mouth, above the insertion of the pro-boscis.
At that instant the bee receded, left the honey, and beat its wings while walking with much agitation; she would have taken flight had not the pencil been withdrawn; she resumed her eating and we again presented the turpentine, still placing it near her mouth; the bee then turned away from the honey, clung to the table and fanned herself during some minutes. A similar test, with oil of marjoram produced the same effect, but in a more speedy and constant manner.
This experiment seems to indicate, therefore, that the organ of smell, in these insects, resides in the mouth or in the parts depending on it.
Bees not occupied in feeding appeared more sensible of this odor, they perceived it at a greater distance, and speedily took flight, whereas, when their trunk was dipped in honey, several parts of the body might be touched without disturbing them from this occupation.
Were they absorbed by their love for honey and distracted by its smell, or were their organs less exposed? This could be ascertained in two ways, either by covering all parts of the body with varnish, leaving only the sensitive organ bare, or by cementing up the part wherein the seat of this sense was supposed to be located, leaving the other parts completely free.
The latter method appearing the more positive and practicable, we seized several bees and, compelling them to unfold their trunks, filled their mouths with flour paste; when this coating was dry enough to prevent them from divesting themselves of it, they were freed; this process did not seem to incommodate them, they breathed and moved as easily as their companions.