DISCOVERY 



197 



temporary with that fair lady and therefore black with 

 age. All that could be distinguished on this little 

 medallion portrait were the faint outlines of a woman'; 

 head and bust, slightly decolletec. Here and there were 

 faint outlines of things which the artist had carefully 

 drawn and coloured — details so obscured by Time that 

 one could hardly tell what they represented. But once 

 the canvas was set up, flooded with light in the 

 darkened laboratory, and viewed through the prism, 

 everything down to the slightest particular and touch 

 of colour was restored to pristine freshness. The 

 writer was able to count the jewels in a magnificent 

 ornament at the lady's waist ; he could see every lock 

 of her hair, almost every hair of the pretty curl which 

 caressed her bosom ; her eyes became as li\dng to him 

 as they were to her contemporaries. 



An old picture of a bouquet of flowers was trans- 

 formed in a similarly marvellous manner. This particu- 

 lar work was in so advanced a stage of obliteration that 

 the flowers seemed to be suspended in mid air above 

 a table. But on being illuminated and viewed through 

 the Nicol's-prism everything sprang into being, with all 

 the freshness of colour given to the still-life subject on 

 the day it left the painter's studio. The flowers — roses, 

 honeysuckle, and other species all easily distinguishable 

 — were seen to be in a dark green glass bowl, partly 

 filled with water, the transparency of which was really 

 admirably depicted. 



A number of landscapes were next examined, and in 

 each case they appeared to the eye as though they had 

 just passed through the hands of an expert restorer. 



" WTiat an admirable aid to the restorer of works of 

 art ! " was the reflection made by more than one of M. 

 Pierre Lambert's guests. And someone voiced the 

 thought. 



" Yes," replied the physicist, with his customary 

 modesty. " But for that I should not have taken the 

 liberty of troubling you to see the application of a 

 phenomenon which is weU-known to us. It does 

 seem to me that this method may be of use to con- 

 noisseurs who wish to judge of the artistic value of 

 old paintings and to determine whether a given work 

 is susceptible of being improved by modifying its 

 varnish." 



Let me sa\', in conclusion, that M. Lambert has in- 

 vented an accessory to his lantern — a V-shaped Xicol's- 

 prism binocular — which advantageously replaces the 

 single tube prism, since it dispenses with any turning 

 of the prisms to the " position of extinction," whilst 

 the arms can be placed at angles to suit all eyes. 



(b) Studying the Human 

 Machine 



By George Frederic Lees 



The first moving platform for the study of the mechan- 

 ism of the human body when walking was made in the 

 L'nited States by Benedict. Xery excellent work was 

 done with it, and it certainly put scientists on the track 

 of a new branch of physiology. But this platform only 

 permitted a study of walking on the flat and at speeds 

 not exceeding five miles per hour. Manifestly this was 

 but the beginning. One is not surprised to hear, 

 therefore, that a French professor has made many 

 improvements on Benedict's apparatus and, thanks to 



GIV^EN AS ..Ki.^i .-> ouwrt .-v., , 

 F.\ST AS IS MILES PER HOUR. 

 .\T A SLOPE OF 25°. 



iM, WHICH CAN BE 

 .-i-Nu .MADE TO TRAVEL AS 

 IT IS HERE REPRESENTED 



Vitamines. Essential Food Factors. By Dk. Ben- 

 j.\MiN Harrow. (Routledge, los. 6i.) 

 An exposition for the general reader by a well-known 

 American writer on physiological chemistn,'. 



the perfected apparatus, has come to many interesting 

 and absolutely new conclusions regarding the working 

 of the human machine. 



This new moving platform is the invention of Pro- 

 fessor Langlois, a member of the Academy of Medicine 

 and professor at the Conservatoire Nationale des Arts 

 et Metiers ; it is to be seen in his laboratory at the 

 Faculty of Medicine in Paris ; and, as has just been 

 explained to the members of the Academy of Sciences, 

 it is possible to obtain a speed of 18 miles and to 

 study with it the physiological effects produced on a 

 person walking up or descending slopes varying from 

 5 to 35 degrees. The man when walking or running 

 on the carpet can be studied by means of appropriate 

 registering apparatus, connected by means of rubber 

 tubes to his body, whilst he is at work. Thus the 

 physiological reactions when walking, running, carrying 

 weights, pushing or pulling a wheelbarrow up the 



