April 2%, 1881] 



NATURE 



617 



Jiminalde Physiqut for March). It shows very well the fringes 

 of a crystal only 2 mm. in diameter and \ mm. in thicUness, and 

 all uniaxial crystals give fringes in it. With the old pincette 

 only two biaxial crystals can be ohserved (nitre and lead cry-ial), 

 the limit for the exterior angle of the axis beni;.< about 17° ; but 

 in the new instrument, a small calamme plate, with axe^ 78° 

 20' apart, shovved the fringes well. 



According to M. Angot ijo^ir. de Phys., March) the psy- 

 chrometer, of whatever form, may give pretty good indications 

 in the hands of careful observers, in these regions ( France), so long 

 as the atmospheric pressure is not far from 760 mm., the wet 

 bulb thermometer is above 1° or 2°, and the difference of the 

 two thermometers remains below 12° ; but otherwise the ordinaiy 

 formuire become illusory. 



The influence of atmospheric electricity on the vegetation of 

 the vine has been studied near Palermo by M. Macagiio [Jour, 

 de Agi: Prat.) thus : Sixteen stocks were rendered more subject 

 to the effects of the electric tension by means of a copper wire 

 inserted vertically with platinum point in the upper end of the 

 fruit branch, while another wire connected the bottom of the 

 branch with the ground. This continued from April to Sep- 

 tember. An acceleration of vegetation was proved by the wood 

 of these stocks containing less uimeral matters and potash than 

 that of the other stocks, while the contrary occurred in the 

 leaves, and in these the potash was mostly in the hitanrate form. 

 A much greater quantity of n.ust was got from the grapes of 

 those vines, and it had considerably more glucose and less acid. 



A DETERMINATION of the electric phenomena which occur 

 on contact of metals and gases has been attempted by Herr 

 Schulze-BerJe in Berlin {IVied. Ann. No. 2). He worUed with 

 a condenser havnng two circular plates of a given metal, the 

 upper plate being connected with an electrometer and submitted 

 to contact with various gases or to vacuum ; the lower connected 

 to earth. The quantity of electriciiy from a known souice requir- 

 ing to be communicated to the upper plate to make its potential 

 equal to the lower, was measured. /nU-r alia, ozone « as found 

 to make gold, platinum, and bra^s negative to a plate of the 

 same metal in air. Hydrogen always made platinum strongly 

 positive, while its inflilence on gold was hardly perceptible, and 

 on brass qualitatively various. Chlorine made platinum nega- 

 tive; ammoniacal gas (from aqueous solution) made br iss positive. 

 The amount of difference of potential with as similar treatment 

 as possible of a given pair of plates was very differeut in the 

 several observations of a series. Nor Could a certain relation 

 be discovered between it and the time of action of the gas. It 

 was greatest with two platinu n plates, one in hydrogen (viz. 

 o"2I4 D). It gradually decreased to a point generally somewhat 

 short of that at the beginning. As to the cau-e of thi^ decrease, 

 the author thinks it probable that a gradual neutralisation of the 

 electrical double layer takes place. 



THE DEVELOPMENT OF HUMAN 

 INTELLIGENCE 



THE Department of Education of the American Social 

 Science Association has issued the following Cir- 

 cular and Register, which we commend to the notice of 

 our readers, some of whom may be able to give Mrs. 

 Talbot answers to the questions given below : — 



We have been made familiar with the habits of plants and 

 animals from the careful investigations which have from time to 

 time been published — the intelligence of animals, even, coming 

 in for a due share of attention. One author alone contiitmtes a 

 book of one thousand pages upon '* Mind in the Lower Animals." 

 Recently some educators in this country have been quietly think- 

 ing that to study the natural develooment of a single child is 

 worth more than a Noah's ark full of animals. Little has been 

 done in this study, at least little has been recorded. It is certain 

 that a great many mothers might contribute observations of their 

 own child's life and development that miiiht be at some future 

 time invaluable to the psychologist. In this belief the Education 

 Department of the American .^ocial Science Association has 

 issued the accompanying Register, and asks the parents of very 

 young children to interest themselves in the subject — 



1. By recognising the importance of the study of the youngest 

 infants. 



2. By observing the simplest manifestations of their life and 

 movements. 



3 By answering fully and carefully the questions asked in the 

 Register. 



4. By a careful record of the signs of development during the 

 coming year, each observation to be verified, if possible, by other 

 members of the family. 



5. By interesting their friends in the subject and forwarding 

 the results to the secretary. 



6. Above all, by perseverance and exactness in recording these 

 observations. 



From the records of many thousand observers in the next few 

 years it is believed that important facts will be gathered of great 

 value to the educator and to the psychologist. 



First Seiies — Register of Physical and Mental 



Development of (='^f=;';\Sf>''=) 



Name and occupation of the father? 



Place and time of father's birth? 



,, ,, mother's ,, ? 



,, ,, baby's ,, ? 



Baby's weight at birth at 3 months? 



„ ,, 6months? at 1 year? 



Is baby strong and healthy, or otherwise? 



At what age did the baby exhibit consciou.sness, and in what 

 manner ? 



At what age did the Baby 



smile ? 



recogni-e its mother ? 



notice its hand ? 



follow a light with its eyes? 



hold up its head? 



sit alone on the floor? 



creep? 



stand by a chair? 



standalone? 



walk alone? 



hold a plaything when put in its hand? 



reach out and take a plaything? 



appear to be right or left handed ? 



notice pain, as the prick of a pin ? 



show a like or dislike in taste? .' 



appear sensible to sound? 



notice the light of a window or turn towards it? 



fear the heat from stove or grate? 



speak, and what did it say? 



How many words could it say 

 at I year? at 18 months? at 2 years? 



Will the mother have the kindness to carefully answer as 

 many as possible of these questions and return this circular, 

 before July 15, 1881, to Mrs. Emily Talbot, Secretary of the 

 Education Department of the American Social Science Associa- 

 tion, 66, Marlborough Street, Boston, Mass. 



Boston, March i, 1881 



In connection with the inquiry indicated above, the following 

 letter from Dr. Preyer of Prussia, addressed to Mrs. Talbot, will 

 be found of interest : — 



Jena, November 22, 1880 



Dear Madam, — It has given me much pleasure to read your 

 letter and the extract of a paper of mine on "psychogenesis," 

 or "the growth of voUtion, intellect, &c., in infants," and I 

 readily comply with your wish to have this paper sent off without 

 delay. You will find it reprinted in the book accompanying 

 this letter, p. 199-237. I am about to publish an extensive 

 work on the same subject, which is to contain all my observa- 

 tions and a careful analysis of the phenomena which the deve- 

 lopment of the faculty of speech presents. This book is to be 

 printed next year. I am sorry to s.ay that a reliable investigator 

 of the whole subject is not known to me. Your newspaper 

 seems to be right in calling the field " as yet almost unbroken.'^ 

 Prof. Kussmaul's "Seelenleben des neugeborenen Menschen" 

 (Leipzig and Heidleberg, 1859), and Mr. C. Darwin's bio- 

 graphical sketch of an infant, contain some [good observations, 

 but both are very short. Many excellent remarks on infants and 

 very young children I find in Mr. C. Darwin's book, "On the 

 Expression of the Emotions." The German books on the subject, 

 although numerous, are nearly worthless ; many are sentimental, 

 giving no facts, or, what is worse, false statements. B. Sigis- 

 mund's " Kind und Welt " (1851) is an exception. 



The case you mention of a child of eleven months expressing 



