For most purposes the solid media are to be preferred, since bacterial growth appears as a discrete mass and accidental contamination can be readily recognized.
Keene's cement and its congeners are made in fixed kilns so constructed that only the gaseous products of combustion come into contact with the gypsum to be burnt, in order to avoid contamination with the ash of the fuel.
The unavoidable contamination with muddy particles of vat-waste is removed by allowing the vatliquor to rest for some hours in a separate tank and settling out the mud.
(2) The Institute is of opinion that in the hands of more or less unskilled workers it is easier to ensure freedom from contamination by Haffkine's ` standard method ' of manufacturing plague vaccine than with the ` water agar process ' as employed by him.
The varying degrees of contamination to which a water surface is subject are the cause of many curious phenomena.
Although throughout a certain range the surface-tension varies rapidly with the degree of contamination, it is remarkable that, as was first fully indicated by Miss Pockels,the earlier stages of contamination have little or no effect upon surface-tension.
It would seem that the surfaces, coming into collision within a fraction of a second of their birth, would still be subject to further contamination from the interior.
H.) protection against plague; (2) on the comparative liability of each fluid to contamination; and (3) on the probable origin of tetanus virus in the Malkowal cases.
Another method of removing grease is to immerse and remove strips of paper by which the surface available for the contamination is in effect increased.
Another consequence of the tendency of a moderate contamination to distribute itself uniformly is the calming effect of oil, investigated by B.
The tension for clean water thus found is considerably lower than that (81) adopted by Quincke, but it seems to be entitled to confidence, and at any rate the deficiency is not due to contamination of the surface.
Only in a few isolated cases has any contamination been traced to fever or other zymotic germs. In this connexion it is worth noting that the infectious diseases hospital has a separate system of drainage which is carefully disinfected, and not allowed to be employed for the purposes of manure.
He would pollinate a wheat stalk, then cover it with a trash bag to prevent contamination by other plants.
It is obvious that the effect would fail if the contamination of the surface had proceeded too far previously to the collision.
In ordinary circumstances, where the artery is obstructed by an agent free from such organismal contamination, the part becomes first red.
Appointed a member of the second royal commission on the pollution of rivers in 1868, he was provided by the government with a completely-equipped laboratory, in which, for a period of six years, he carried on the inquiries necessary for the purposes of that body, and was thus the means of bringing to light an enormous amount of valuable information respecting the contamination of rivers by sewage, trade-refuse, &c., and the purification of water for domestic use.
Thus in1877-1878efforts were made to minimize contamination by segregating the worst criminals and restricting conversation at exercise.
But the work is too arduous to allow of long and desultory conversation; the chance of contamination is now minimized by the careful separation of the less hardened from the old offenders.
It has been proved, however, that the question is one of contamination, and that a water surface may be prepared so as to behave in the same manner as alcohol.
In the absence of dust and greasy contamination, the obliquely colliding jets may rebound from one another without coalescence for a considerable time.
The media from the store-flasks are placed in glass test-tubes or small flasks, protected from contamination by cotton-wool plugs, and are sterilized by heat.
It is necessary to note that von Soden is able to place D in this group because he regards it as owing many of its most remarkable readings to contamination with the Latin version.
If the injury be a small incised wound through the skin and subcutaneous tissues without any septic contamination, there usually follows a minimum of reaction on the part of the tissues.
Yet tons of caustic soda are fused daily in chemical works in iron pots without thereby suffering contamination, which seems to show that (clean) iron, like gold and silver, is attacked only by the joint action of fused alkali and air, the influence of the latter being of course minimized in large-scale operations.
For example, we find him arguing for the legitimacy of judicial punishments and military service against an over-literal interpretation of the Sermon on the Mount; and he took an important part in giving currency to the distinction between evangelical " counsels " and " commands," and so defending the life of marriage and temperate enjoyment of natural good against the attacks of the more extravagant advocate of celibacy and self-abnegation; although he fully admitted the superiority of the latter method of avoiding the contamination of sin.
It is, therefore, further recommended (a) that the milk be rapidly cooled or chilled, as the lower the temperature the less do the bacteria multiply, (b) that contamination during railway transit be avoided by dustproof locked milk cans.
The cockle is liable to the same suspicion as the oyster of conveying the contamination of typhoid fever where the shores are polluted, but as it is boiled before being eaten it is probably less dangerous.