Biological FactorsThese include the reactions of plants and animals on the habitat.
The reactions of the nitroparaffins with nitrous acid are very characteristic and have been used as a method for discriminating between the primary, secondary and tertiary alcohols (V.
The healthy bone marrow reacts with remarkable rapidity to the demand for more blood cells which may be required by the organism; its reactions and variations in disease are very striking.
Uncertain what to think of their reactions, Deidre turned to Wynn.
It is a colourless fuming liquid boiling at 90.5° C. With water and with ammonia it undergoes the same reactions as the chloride.
Our perceptions differentiate but imperfectlysymptonis which are due to very different causes and reactions, probably because the organization of the plant is so much less highly specialized than that of higher animals.
B~it the staining reactions of nuclei may vary at different stages of their development; and it i~ probable that there is no method of staining which differentiates with certainty the various morphological constituents of the nucleus.
2, L), a nucleolus appears, a nuclear membrane is formed, and daughter nuclei are thus constituted which possess the same structure and staining reactions as the mother nucleus.
The dominant forms result from crustal movements, the subsidiary from secondary reactions o during the action of the primitive forms on mobile distri butions.
The reactions taking place are complicated, and the solution contains ultimately small drops of sulphur in suspension, a colloidal sulphur (which Spring (Rec. tra y.
The attempt to work out either of the reactions against Thomism in new theological systems is pretty much confined to Germany.
By his insistence upon the use of the balance as a quantitative check upon the masses involved in all chemical reactions, Lavoisier was enabled to establish by his own investigations and the results achieved by others the principle now known as the " conservation of mass."
Gerhardt found that reactions could be best followed if one assumed the molecular weight of an element or compound to be that weight which occupied the same volume as two unit weights of hydrogen, and this assumption led him to double the equivalents accepted by Gmelin, making H= 1, 0 =16, and C = 12, thereby agreeing with Berzelius, and also to halve the values given by Berzelius to many metals.
This link was the full extension of Avogadro's theory to all substances, Cannizzaro showing that chemical reactions in themselves would not suffice.
If this be the case, however, it is evident that there is no real distinction between the reactions which take place when two elements combine together and when an element in a compound is displaced by another.
The combination, as it is ordinarily termed, of chlorine with hydrogen, and the displacement of iodine in potassium iodide by the action of chlorine, may be cited as examples; if these reactions are represented, as such reactions very commonly are, by equations which merely express the relative weights of the bodies which enter into reaction, and of the products, thus Cl = HC1 Hydrogen.
Balard discovered chlorine monoxide in 1834, investigating its properties and reactions; and his observations on hypochlorous acid and hypochlorites led him to conclude that " bleaching-powder " or " chloride of lime " was a compound or mixture in equimolecular proportions of calcium chloride and hypochlorite, with a little calcium hydrate.
Similarly he represented the reactions investigated by Liebig and Wehler on benzoyl compounds as double decompositions.
It is necessary, therefore, to avoid reactions involving such intermolecular migrations when determining the orientation of aromatic compounds.
Methane, tetrachlormethane, &c., to yield aromatic compounds when subjected to a high temperature, the so-called pyrogenetic reactions (from Greek 7rup, fire, and - yon, fco, I produce); the predominance of benzenoid, and related compounds-naphthalene, anthracene, phenanthrene, &c.-in coal-tar is probably to be associated with similar pyrocondensations.
Hitherto we have generally restricted ourselves to syntheses which result in the production of a true benzene ring; but there are many reactions by which reduced benzene rings are synthesized, and from the compounds so obtained true benzenoid compounds may be prepared.
- We have previously alluded to the relative stability of the benzene complex; consequently reactions which lead to its disruption are all the more interesting, and have engaged the attention of many chemists.
The methods of chemical analysis may be classified according to the type of reaction: (I) dry or blowpipe analysis, which consists in an examination of the substance in the dry condition; this includes such tests as ignition in a tube, ignition on charcoal in the blowpipe flame, fusion with borax, microcosmic salt or fluxes, and flame colorations (in quantitative work the dry methods are sometimes termed " dry assaying "); (2) wet analysis, in which a solution of the substance is treated with reagents which produce specific reactions when certain elements or groups of elements are present.
It must be mentioned here that the reactions of any particular substance are given under its own heading, and in this article we shall only collate the various operations and outline the general procedure.
It is unnecessary here to dwell on the precautions which can only be conveniently acquired by experience; a sound appreciation of analytical methods is only possible after the reactions and characters of individual substances have been studied, and we therefore refer the reader to the articles on the particular elements and compounds for more information on this subject.
P. 411), the cycle of reactions probably being as follows: NO 2 [[Nhoh-Hno 2 +Hno]]; HNO-}-RI-CHI+RNO (CH3CH2NO-->CH 3 CH: N OH).
The reactions are represented as (I) N2+3H2+2C0 -1-2H 2 0=2H CO 2 NH 4 (Ammonium formate).
They give the biuret and xanthoproteic reactions, and form salts with both acids and bases.
They are loose, white, non-hygroscopic powders, soluble in water and salt solutions, and have an acid reaction; they give the colour reactions of albumins.
The mucins and mucoids belong to this group; they are acid and contain no phosphorus; they give the albumin colour reactions but are not coagulated by heat.
Mucoids resemble mucins in their composition and reactions, but differ, in general, in their physical properties.
Repair Of Injuries In the process of inflammation we have a series of reactions on the part of the tissues, and fluids of the body, to counteract the ill effects of irritation or injury, to get rid of the cause, and to repair its results.
In the various reactions of the tissues against the exciting cause of the injury we see a striking example of a beautifully organized plan of attack and defence on the part of the organism.
One can easily demonstrate all the actions and reactions which take place in this form of acute inflammation.
At this point one's attention is focused on the wonderful reactions possessed by the healthy tissues to combat these evil influences.
The reactions of the tissues vary in degrees according to the nature and severity of the injury.
There is neither any absolute difference nor a constancy in their chemical reactions, and there can be brought about a transition of the " colloid " material into the " mucoid," or conversely.
Few simple derivatives of the a-series are known, those which have been prepared result by such reactions as the condensation of aminoguanidine or a similar type of compound (e.g.
The aromatic aldehydes resemble the aliphatic aldehydes in most respects, but in certain reactions they exhibit an entirely different behaviour.
But his best known contribution to general chemistry is his work on the phenomena of reversible reactions, which he comprehended under a general theory of " dissociation.
Secondary reactions take place at the same time, yielding more particularly hydrocarbons of the paraffin series.
Thus neither a chlorate, which contains the ion C103, nor monochloracetic acid, shows the reactions of chlorine, though it is, of course, present in both substances; again, the sulphates do not answer to the usual tests which indicate the presence of sulphur as sulphide.