Illustration: 254] Mr. William Henry Barnard, in the course of some experiments upon the impregnation of ropes with caoutchouc, at the factory of Messrs.
A window on each side enables the operator to judge how the impregnation goes on by the colour of the air, and also gives light for making the arrangements within at the commencement of the process.
In circumstances where a stronger impregnation with this antiseptic oil may be necessary, common wood vinegar may be heated to 167 deg.
It consists of carbon in a peculiar state of aggregation, with an extremely minute and apparently accidental impregnation of iron.
Three years are requisite to give the full calcareous impregnation to the indigenous madders of Avignon.
This impregnation is still more fully ensured by laying the padded cloth aside in wooden troughs during 16 or 18 days.
From hence it should seem to follow, that the former kind of eggs are first in the oviducts, and, if impregnation be not effected within a given time, that all the worker embryos perish.
Huber is of opinion that a single impregnation fertilizes all the eggs that a queen will produce during her whole life, which is sometimes more than two years[182].
The office of the males, which are also winged, and at the time of swarming are extremely numerous, is merely the impregnation of the females: after the season for this is passed, they die.
When her impregnation takes place late in the year, she does not begin laying till the following spring.
The impregnation of the female is supposed to take place after this confinement, and she soon begins to furnish the infant colony with new inhabitants.
Impregnation is the only mission of intercourse, and after that has taken place, intercourse can subserve no other purpose than sensual gratification.
Conception or impregnation takes place by the union of the male sperm and female sperm.
You have most agreeably surprised me, Sir, with your interesting discovery of the impregnation of the queen bee.
But as new experiments will unquestionably occur to you, whether on the impregnation of the queen or on other points, may I solicit you to suggest them?
In my Journal, I find a detail of many experiments on the retarded impregnation of queen bees, so many, that transcribing the whole would be tedious.
But, what is the remote cause of this peculiarity; or, in other words, why does the delay of impregnation render queens incapable of laying the eggs of workers?
Hitherto no other effect has been observed from the retarded impregnation of animals, but that of rendering them absolutely sterile.
But they so far correspond with queens whose impregnation has been retarded, that they sometimes lay in royal cells.
Let me remind you, that male and female ants copulate in the air; and that after impregnation the females return to the ant hills to deposit their eggs.
The distinction is important, for the same certainty of instinct is no longer conspicuous in the conduct of those females whose impregnation has been deferred.
The perfect impregnation of the water with gas, however, requires time.
The difficulty of determining the precise time when impregnation takes place in the human subject, renders it almost impossible, in any case, to calculate with absolute certainty the duration of pregnancy.
Thus the act of ordinaryimpregnation and the development of each part in each being are closely analogous processes.
The causes which induce variability act on the mature organism, on the embryo, and, probably, on the sexual elements before impregnation has been effected.
I have found sorts of potatoes which would not bear seed from impregnation with the pollen of their own flowers would bear it when impregnated with other pollen.
So that, with these illegitimate unions, the act ofimpregnation is less assured, and the fertility slightly less, when the pollen and ovules belong to the same flower, than when belonging to two distinct individuals of the same form.
This was the first stream we had for a long time seen traversing rocks of the secondary formation, whose waters were free of an impregnation of muriate of soda and other salts.
In the districts occupied by that rock, we have observed several copious springs, but not one whose waters were without a very manifest impregnation of muriate of soda, or other saline substances.
The sweetish metallic taste observed in the water of one or two, appears to depend on animpregnation of sulphate of iron.
It instances both the heredity connected with hypospadias and the peculiar circumstances under which impregnation at times takes place; it is reported by Dr.
It is an obstacle to the impregnation of the young female by immature, aged, or feeble males.
This activity is present almost from the first--a few days after the impregnation of the ovum--in the breasts, and quickly becomes obvious to inspection and palpation.
It is in the human species that the tendency to limitation of offspring is most marked, combined at the same time with a greater aptitude for impregnation than exists among any lower mammals.
Janke quotes numerous cases in which there has been impregnation in virgins who have merely allowed the penis to be placed in contact with the vulva, the hymen remaining unruptured until delivery.
There is far more of all these things common to the impregnate ovum and the ovum immediately before impregnation, or again between the impregnate ovum, and both the ovum before impregnation and the spermatozoon which impregnated it.
The method of impregnation employed has always been an imitation of the Russian method introduced into America in 1871.
This is a favorable circumstance, since the milt of a single male is fully equal to the impregnation of the ova of many females.
Some physiologists have attempted to account for these remarkable results from a first impregnation by the close attachment and freely intercommunicating blood-vessels between the modified embryo and the mother.
Many authors maintain that impregnation takes place in the closed flower, but I am sure from my own observations that this is not the case, at least with those varieties to which I have attended.
Where elastic tissue predominates, diphtheritic impregnation is slow to take place, and recovery is also slow when the tissue has finally submitted.
In respect to atmospheric infection by yellow fever, localizations of aërial impregnation are often observable, not common in other air-infecting diseases.
Under these circumstances atmospheric impregnation is conclusive.
The effect of this impregnation was to increase the dimensions as well as the specific gravity of the wood, every solid inch having increased one-twentieth in size and twenty-one twenty-fifths in weight.
Even where such synchronism does prevail, so that a cross impregnation is effected, the chances are very numerous against the establishment of a hybrid race.
The plan of impregnation adopted, was the cutting off of the anthers of the plant intended for fructification before they had shed pollen, and then laying on foreign pollen upon the stigma.
If their organization be very remote, impregnation never takes place; if somewhat less distant, seeds are formed, but always imperfect and sterile.
The impregnation from new mineral springs, caused by earthquakes in volcanic countries, is perhaps here alluded to.
The predominant characteristic of Turgenieff's talent is here revealed in a particularly brilliant manner: a profound impregnation with Nature,--an impregnation which reached the point almost of fusion with it.
The leather, if genuine quality, is very watertight and strong, and owing to its impregnation with the empyreumatic oil, it wards off the attacks of insects.
To return to the particular question of the impregnation of the Virgin Mary by the Holy Ghost, we are referred to the gospels for testimony to the fact.
Apello, experimenting with Teleostean fish, found that very often impregnation and segmentation occurred, but that the development broke down immediately afterwards.
Finally, when the actual impregnation of the egg is possible naturally, or has been secured by artificial means, the development of the hybrid may stop at an early stage.
The seminal fluid may pass by its loose rim and impregnation may result.
For many reasons which I need not enumerate here, the precautions against impregnation can most easily and effectively be taken by the woman, rather than by the man.
Many authors maintain that impregnation takes place in the closed flower, but I am sure from my own observation that this is not the case, at least with those varieties to which I have attended.
With some kinds it will be advisable to assist nature by artificial impregnation with a camel hair pencil, carefully placing the pollen on the point of the stigma.
