OCTOHEK 2 1, 1887.] 



SCIENCE 



199 



on zoology and a child's picture-book of animals. The chapters 

 are divided into short, numbered paragraphs, each headed with a 

 full-faced subtitle, in the style of a school ' reader.' This, and the 

 rather pedagogical style, render it nearly certain that young people 

 will not 7-ead it ; while the necessary sketchiness of its contents, 

 and the innumerable omissions, render it nearly useless as a book 

 of reference. It may have some value in the hands of a teacher as 

 suggesting a series of topics for elaboration, but, even so, we are 

 confident that the patient e.Kamination of half a dozen typical speci- 

 mens would furnish better results than this fragmentary treatment 

 of several hundred. It is essentially a compilation. After reading 

 the book, one dare not swear that the author has ever seen a single 

 one of all the animals described, unless it be some of the common 

 sea-creatures of the Massachusetts coast. The illustrations are 

 attractive, reasonably accurate, and many of them artistic. The 

 mechanical part of the book is well done. 



Die Psychischen Stdrungen des Kindesaltcrs. Von Dr. H. 

 Emminghaus. Tubingen. 



While this work by an eminent German alienist is primarily 

 designed for specialists, it contains a number of interesting obser- 

 vations valuable to all v\'ho are concerned in the training of chil- 

 dren, and illustrating from an unusual point of view certain marked 

 characteristics of child-mind. The limitation of ' childhood ' strictly 

 to the period before the establishing of the functions that connect 

 the individual with the race is at once significant : it gives the 

 physiological basis for much of what is distinctive in child-life, and 

 accents the enormity of the field of thought and feeling which the 

 approach of adolescence suddenly reveals. As mental disease is to 

 a large extent a concomitant of civilization, and this in turn is 

 dependent upon a general and prolonged brain-culture, it is easy to 

 see that the child who has not yet reached the stage where char- 

 acter is established, where keen competition e.xcites each brain-cell 

 to a maximum of action, is spared a large proportion of mental 

 disease. This fact, then, that mental diseases are far less common 

 among children than among adults, with the further fact that the 

 affliction of children by a large class of mental diseases not uncom- 

 mon in adults is a sporadic occurrence, it is essential to bear in 

 mind. Since the influence of a pernicious environment is respon- 

 sible for only a small share of mental breakdown in childhood, it 

 follows that heredity — ' the sins of the fathers ' — is the great dis- 

 posing cause. And this shows itself in the production of two 

 classes of children : ( i ) those who from birth show the marks of 

 mental deficiency or perversity, or who, without any accident or 

 maltreatment, are sure to show such marks within a few years ; 

 { 2 ) those who show almost no suspicious symptoms in early child- 

 hood, but in whom the strains demanded of a civilized city child 

 cause mental breakdown. It is this last numerous class of children 

 that is open to the wise treatment of the intelligent parent and 

 teacher as well as of the knowing physician. Another noteworthy 

 point is that the mental abnormality of a*child can be determined 

 only by reference to a normal child of the same age, and with an 

 appreciation of certain traits, which, almost always pathological 

 when occurring in adults, are within the range of normal indi- 

 viduality in children. The analogy between the acts of the insane 

 and the traits of children is often drawn. This includes more than 

 the degenerative processes of senile dementia (second childhood ), 

 and is shown, for example, in the passion for collecting all sorts of 

 curiosities, odds and ends, and the Uke ( common to certain forms 

 of mania). The most striking instance of this analogy is that of 

 the wantonness of the actions in the transition period between boy- 

 hood and youth, for which the Germans have the term Flegeljahj-c. 

 Here there is all the recklessness of demeanor, bigness of plans, 

 swaggering egotism, and excitable caprice characteristic of devel- 

 oped mania. But it is only in the presence of predisposing causes 

 that this period leaves the region of the normal ; and the frequency 

 of runaways from home, and other cravings for a free roaming life 

 that appear at this age, suggest that a rational outlet for this 

 superfluous energy might be provided. 



Leaving these general considerations, a few points of illustrative 

 value should be mentioned. In an interesting chapter on suicides 

 in children, Dr. Emminghaus accents the importance of one-sided 

 precocity as a disposing factor. Ideas belonging to a more mature 



period of life are by accident, by exciting literature or other cause, 

 planted in a yielding brain, that has not yet acquired the stability of 

 will, or the firm distinctiveness of moral habit, that keeps such 

 weird notions from realization in action. Nothing could better 

 illustrate the mischievous tendency fostered by competitive exami- 

 nations, to goad children on ahead of their years, with a show of 

 great brilliancy, but a brilliancy dangerous by lack of a sound 

 physiological basis. The triviality of the alleged cause of suicide is 

 only a further evidence of the abnormality (usually hereditary) of 

 such children.' 



Idiocy and imbecility have always been the type of mental dis- 

 ease in children. Their ultimate relation with other forms of in- 

 sanity is likewise well understood, and it has been spoken of as 

 nature's method of cutting off the progeny of a degenerate strain. 

 While by its nature incurable, modern study has succeeded, by an 

 early appreciation of the condition, in rescuing all but the severest 

 forms from the utter helplessness formerly so common. 



Finally, this very imperfect sketch of Dr. Emminghaus's point of 

 view should not be completed without mentioning that the sharply 

 defined plan of his work prevents him from recognizing that host 

 of mental affections whose germs are often innate, and whose 

 prodromal symptoms often clearly manifest in childhood, but 

 which come to distinct view only later in life, especially at the 

 periods of intense physiological change. 



The Relative Proportions of the Steam-Engi7ie. By William 

 Dennis Marks. Philadelphia, Lippincott. 8°. 



The little book lying before us is a volume containing matter of 

 value and interest to technical schools. It represents the first 

 attempt which, so far as we are aware, has ever been made to de- 

 termine, by correct methods and in any considerable detail, the 

 proportions of the parts of the steam-engine. It is a singular fact, 

 that notwithstanding the importance of the steam-engine, and its 

 attractiveness to scientific writers on applied mechanics, no treatise 

 of this character has ever before been produced. The general 

 theory of the heat-engines has, especially during the present gener- 

 ation and since the time of Rankine and of Clausius' work, been 

 written and re-written by many writers, great and small, and has 

 been elaborated with all the ingenuity that such authors are capable 

 of ; but not one has hitherto had the good judgment, the patience, 

 and the abiUty, to produce a good book on the proportioning of its 

 rods and cranks, its fly-wheels and its cylinders. Some such work 

 has been done by a few European writers ; but none have devoted 

 themselves to the production of a special treatise upon the subject. 



Professor Marks has gone into the work with a zeal which could 

 not but be fruitful of result, and has produced a book which 

 will be of very great value to the profession and in the schools. 

 Collating all that could be found in standard writers on the strength 

 of materials and on machine design, he has added much useful 

 material as the result of his own investigations, and has thus put 

 into convenient form and into a single volume a very large amount 

 of fact and calculation indispensable to the student in engineering 

 and to the designer of machinery of this kind. A chapter is devoted 

 to the study of the proportions of the steam-cylinder and the calcu- 

 lation of power ; another to the sizes of bolts, areas of ports, and 

 size of piston-rods. The proportions of fastenings, such as gibs and 

 keys ; the size and shape of the connecting-rod and its connections ; 

 the sizes, forms, and proportions of crank-pins, and the proportion- 

 ing of the crank in wrought or cast iron and in steel, — form the sub- 

 jects of succeeding chapters ; and the size of the crank-shaft in the 

 several available metals is calculated by carefully established for- 

 mulas and rules. Among the best parts of the book are the studies 

 of the effect of the fly-wheel, and its action as a regulator. This is 

 probably the most complete and practically valuable discussion of 

 this subject to be found. The last chapter, that on the governor, 

 is the least satisfactory in the book ; and it would seem that the 

 writer had not yet worked up to that point in his progress toward 

 his ideal of his book. 



^ It is interesting to note that even in children the modes of suicide in the two 

 sexes are strikingly different. The boys in seventy-five per cent of all cases hang 

 themselves, in iifteen per cent drown themselves, in three percent poison themselves,^ 

 and never stab themselves. Of the girls, only ten per cent meet death by hangins, 

 but sixty-four per cent by drowning, thirteen per cent by poison, and eight per cent 

 by stabbing. 



