Feb. 17, 1888.] 



SCIENTIFIC NEAVS. 



161 



abdomina, and their heads too heavy for the necks to 

 support, we could not but marvel." 



Davy and Whewell might further have found in 

 Erasmus Darwin's " Zoonomia " (Vol. I., p. 187-194), 

 some remarks on the different stages of growth which 

 animals of different species have reached when first 

 brought into the world. The author uses these words : 

 " The chicks of the pheasant and the partridge have more 

 perfect plumage, more perfect eyes, and greater aptitudes 

 for walking, than the callow nestlings of the dove or the 

 wren. It is only necessary to show the former their 

 food and teach them to pick, whilst the latter for days 

 obtrude a gaping mouth." 



Prof. Whewell, being a German scholar, might have 

 read how Lorenz Oken divided the class "birds " into the 

 main groups " nest sitters " and " nest quitters " (nest- 

 hocker and nest-fluechter), according as when hatched 

 they remain helpless in the nest, or are at once able to 

 run about and seek food for themselves. 



Davy puts into the mouth of his " Ornither " a very 

 lame explanation of the fact that most birds cannot fly as 

 soon as hatched. Before they can take flight they have 

 to await, not alone the growth of their feathers, but the 

 development of the muscles. The fact that parent birds 

 educate their young is clearly shown by the interesting 

 observations of Dr. C. Abbott (Journal of Science, VI. , 

 second series, p. 361). He remarks : " With the simple 

 growth of the wing-feathers there does not come the 

 ability to fly. Just as creeping precedes walking in 

 children, this is a gradually acquired power. The com- 

 mencement may be termed ' flapping,' and consists in 

 simply breaking the force of a descent ; this is followed 

 by a more effectual use of the wings and by horizontal pro- 

 gression, and it is some time subsequent to this that the 



young birds attain to the power of upward flight 



When a sufficient growth of feathers has been obtained, 

 the parent-birds directly and indirectly instruct them, or, 

 perhaps, more properly force them to use their wings." 

 He describes the manner in which a pair of indigo-birds 

 forced their brood to fly, and the progress made by the 

 nestlings in the course of five days. " Indirect instruc- 

 tion " is also given, the parents ceasing to bring food to 

 the nest and thus compel the young ones to follow them. 

 " Once out of the nest they soon endeavour to walk on 

 air, as it were, and falling, open their wings, and thus 

 take the initial step. This ceasing to bring the food to 

 the young while yet in the nest is done, in some in- 

 stances I judge, only to draw them from the nest ; and 

 then they feed them as before, but not so frequently, 

 which leads the young to voluntarily move from point to 

 point. In the case of birds of prey, the process is more 

 prolonged, and the young are still fed by their parents 

 after leaving the nest." For the training of young eagles 

 we may refer to Deuteronomy xxxii. 11. 



Dr. Spalding's observations on young swallows do not, 

 in reality, controvert those of Dr. Abbott : " A young 

 swallow will as little need instruction in flying, when its 

 muscles are once developed, as does a chick is the art of 

 walking." 



Thus we see that the condition of young animals is 

 analogous to that of the human infant. The child, 

 indeed is still slower in learnmg to walk than the 

 kitten or the young ape, \not because he has to learn 

 in a different manner, but because the development of 

 his muscles and joints is still more gradual ; because he 

 has to support himself on one pair of limbs only, render- 

 ing his base narrower, and his centre of gravity higherfrom 



the ground. Finally, as we have already shown, the hinder 

 extremities gain strength more slowly than the anterior.. 

 Surely, therefore, the helplessness of the child is no 

 exceptional fact, and the hypotheses built upon it by 

 rhetoricians may be safely dismissed to dreamland,, 

 whence they came. 



ARTISTS' COLOURS. 



FROM the cochineal insect is obtained the gorgeous 

 carmine, as well as the crimson, scarlet and purple 

 lakes. Sepia is the inky fluid discharged by the cuttle 

 fish, to render the water opaque for its own concealment 

 when attacked. Ivory black and bone black are made 

 out of ivory chips. The exquisite Prussian blue is got 

 by fusing horses' hoofs and other refuse animal matter 

 with impure potassium carbonate. It was discovered by 

 an accident. In the vegetable kingdom are included the 

 lakes, derived from roots, barks and gums. Blue black 

 is from the charcoal of the vine stalk. Lampblack is 

 soot from certain resinous substances. From the madder 

 plant, which grows in Hindostan, is manufactured 

 Turkey red. Gamboge comes from the yellow sap of a 

 tree, which the natives of Siam catch in cocoanut shells. 

 Raw sienna is the natural earth from the neighbourhood 

 of Sienna, Italy. When burned it is burned sienna. Raw- 

 umber is an earth from Umbria, and is also burned. 



To the vegetable pigments may be added Indian ink,, 

 which is said to be made from burnt camphor. The 

 Chinese, who alone can produce it, will not reveal 

 the secret of its composition. Mastic — the base of the 

 varnish so called — is from the gum of the mastic tree,, 

 indigenous to the Grecian archipelago. Bistre is the soot 

 of wood. Of real ultramarine but little is found in the 

 market. It is obtained from the precious lapis lazuli, and 

 commands afabulous price. Chinese whiteis prepared from 

 zinc. Scarlet is iodide of mercury, and cinnabar, or native- 

 Vermillion, is a quicksilver ore. — New Orleans Picayune^ 



A GOOD THING FOR BOYS. 



MANUAL training is one of the few good things that 

 are good for everybody. It is good for the rich 

 boy, to teach him respect for the dignity of work. It is 

 good for the poor boy, to increase his facility for handling 

 tools, if tools prove to be the thing he must handle for a 

 living afterwards. The boy utterly .unable, even if he 

 were studious, to keep up in book, knowledge with the 

 brighter boys, becomes discouraged, dull, and moody- 

 Let him go to the work-room for an hour, and find that 

 he can make a box or plane a rough piece of board as 

 well as the brighter scholar, nay, very likely better than 

 his brighter neighbour, and you have given him an im- 

 pulse of self-respect that is one of untold benefit to him 

 when he goes back to his studies. He will be a brighter 

 and a better boy for finding out something that he can 

 do wefl. It is not planing the board that does him good ; 

 it is planing the board in the presence of other boys who 

 can no longer look down upon him when they see how 

 well he can plane. He might go home after school and 

 plane a board in the bosom of his family, or go to an 

 eveningschoolto learn toplane without a quarter part, nay,, 

 without any, of the invaluable effect upon his manhood 

 that it will have to let him plane side by side with those 

 who in mental attainments may be his superiors. — From 

 Manual Training in Schools, by Alice Wellington Rollins,, 

 in the American Magazine for January. 



