acquires new and especial forms to express new and especial events in human life。 Geiger＇1＇ cites the following example of such changes in the meaning of words。 ‘‘Mriga'' means in Sanscrit； ‘‘wild beast；'' in Zend it means merely ‘‘bird；'' and the equivalent Persian term ‘‘mrug'' continues to mean only ‘‘bird；'' so that the barnyard fowls； song…birds； etc。； are now called ‘‘mrug。'' Thus the first meaning； ‘‘wild animal'' has been transmuted into its opposite； ‘‘tame animal。'' In other cases we may incorrectly suppose certain expressions to stand for certain things。 We say； ‘‘to bake bread； to bake cake； to bake certain meats；'' and then again； ‘‘to roast apples； to roast potatoes； to roast certain meats。'' We should laugh if some foreigner told us that he had ‘‘roasted'' bread。
＇1＇ Ursprung u。 Eutwieklung der Sprache。 Stuttgart； 1869。
These forms of expression have； as yet； no relation to character； but they are the starting…point of quite characteristic modes which establish themselves in all corporations； groups； classes； such as students； soldiers； hunters； etc。； as well as among the middle classes in large cities。 Forms of this kind may become so significant that the use of a single one of them might put the user in question into jeopardy。 I once saw two old gentlemen on a train who did not know each other。 They fell into conversation and one told the other that he had seen an officer； while jumping from his horse； trip over his sword and fall。 But instead of the word sword he made use of the old couleur…student slang word ‘‘speer；'' and the other old boy looked at him with shining eyes and cried out ‘‘Well； brother； what color？''
Still more remarkable is the mutation and addition of new words of especially definite meaning among certain classes。 The words become more modern； like so much slang。
The especial use of certain forms is individual as well as social。 Every person has his private usage。 One makes use of ‘‘certainly；'' another of ‘‘yes； indeed；'' one prefers ‘‘dark；'' another ‘‘darkish。'' This fact has a double significance。 Sometimes a man's giving a word a definite meaning may explain his whole nature。 How heartless and raw is the statement of a doctor who is telling about a painful operation； ‘‘The patient sang！'' In addition； it is frequently necessary to investigate the connotation people like to give certain words； otherwise misunderstandings are inevitable This investigation is； as a rule； not easy； for even when it is simple to bring out what is intended by an expression； it is still quite as simple to overlook the fact that people use peculiar expressions for ordinary things。 This occurs particularly when people are led astray by the substitution of similars and by the repetition of such a substitution。 Very few persons are able to distinguish between identity and similarity； most of them take these two characters to be equivalent。 If A and B are otherwise identical； save that B is a little bigger； so that they appear similar； there is no great mistake if I hold them to be equivalent and substitute B for A。 Now I compare B with C； C with D； D with E； etc。； and each member of the series is progressively bigger than its predecessor。 If now I continue to repeat my first mistake； I have in the end substituted for A the enormously bigger E and the mistake has become a very notable one。 I certainly would not have substituted E for A at the beginning； but the repeated substitution of similars has led me to this complete incommensurability。 gou_；'' to stride proudly； ‘‘dna；'' to demand。 The Mpongwes say； ‘‘m tonda；'' I love； and ‘‘mi tnda；'' I do not love。 Such differentiations in tone our own people make also； and the mutation of meaning is very close。 But who observes it at all？
Important as are the changes in the meanings of words； they fall short beside the changes of meaning of the conception given in the mode of exposition。 Hence； there are still greater mistakes； because a single error is neither easily noticeable nor traceable。 J。 S。 Mill says； justly； that the ancient scientists missed a great deal because they were guided by linguistic classification。 It scarcely occurred to them that what they assigned abstract names to really consisted of several phenomena。 Nevertheless； the mistake has been inherited； and people who nowadays name abstract things； conceive； according to their intelligence； now this and now that phenomenon by means of it。 Then they wonder at the other fellow's not understanding them。 The situation being so； the criminalist is coercively required； whenever anything abstract is named； first of all to determine accurately what the interlocutor means by his word。 In these cases we make the curious discovery that such determination is most necessary among people who have studied the object profoundly； for a technical language arises with just the persons who have dealt especially with any one subject。
As a rule it must be maintained that time； even a little time； makes an essential difference in the conception of any object。 Mittermaier； and indeed Bentham； have shown what an influence the interval between observation and announcement exercises on the form of exposition。 The witness who is immediately examined may； perhaps； say the same thing that he would say several weeks after but his presentation is different； he uses different words； he understands by the different words different concepts； and so his testimony becomes altered。
A similar effect may be brought about by the conditions under which the evidence is given。 Every one of us knows what surprising differences occur between the statements of the witness made in the silent office of the examining justice and his secretary； and what he says in the open trial before the jury。 There is frequently an inclination to attack angrily the witnesses who make such divergent statements。 Yet more accurate observation would show that the testimony is essentially the same as the former but that the manner of giving it is different； and hence the apparently different story。 The difference between the members of the audience has a powerful influence。 It is generally true that reproductive construction is intensified by the sight of a larger number of attentive hearers； but this is not without exception。 In the words ‘‘attentive hearers'' there is the notion that the speaker is speaking interestingly and well； for otherwise his hearers would not be attentive； and if anything is well done and is known to be well done； the number of the listeners is exciting； inasmuch as each listener is reckoned as a stimulating admirer。 This is invariably the case。 If anybody is doing a piece of work under observation he will feel pleasant when he knows that he is doing it well； but he will feel disturbed and troubled if he is certain of his lack of skill。 So we may grant that a large number of listeners increases reproductive constructivity； but only when the speaker is certain of his subject and of the favor of his auditors。 Of the latter； strained attention is not always evidence。 When a scholar is speaking of some subject chosen by himself； and his audience listens to him attentively； he has chosen his subject fortunately； and speaks well； the attention acts as a spur； he speaks still better； etc。 But this changes when； in the course of a great trial which excites general interest； the witness for the government appears。 Strained attention will also be the rule； but it does not apply to him； it applies to the subject。 He has not chosen his topic； and no recognition for it is due himit is indifferent to him whether he speaks ill or well。 The interest belongs only to the subject； and the speaker himself receives； perhaps； the undivided antipathy； hatred； disgust； or scorn； of all the listeners。 Nevertheless； attention is intense and strained； and inasmuch as the speaker knows that this does not pertain to him or his merits； it confuses and depresses him。 It is for this reason that so many criminal trials turn out quite contrary to expectation。 Those who have seen the trial only； and were not at the prior examination； understand the result still less when they are told that ‘‘nothing'' has altered since the prior examinationand yet much has altered； the witnesses； excited or frightened by the crowd of listeners； have spoken and expressed themselves otherwise than before until； in this manner； the whole case has become different。
In a similar fashion； some fact may be shown in another light by the manner of narration used by a particular witness。 Take； as example； some energetically influential quality like humor。 It is self…evident that joke； witticism； comedy； are excluded from the court…room； but if somebody has actually introduced real； genuine humor by way of the dry form of his testimony； without having crossed in a single word the permissible limit； he may； not rarely； narrate a very serious story so as to reduce its dangerous aspect to a minimum。 Frequently the testimony of some funny witness makes the rounds of all the newspapers for the pleasure of their readers。 Everybody knows how a really humorous person may so narrate experiences； doubtful situations of his student days； unpleasant traveling experiences； difficult positions in quarrels； etc。； that every listener must laugh。 At the same time； the events t