136 
NATCORE 
[Dec. 15, 1870 

thought applicable to the explanation of an infinite variety of 
phenomena, and they recommend that every one be placed in 
his youth somewhere where he may best learn such general prin- 
ciples. The first party takes little account of the development of 
the mental powers as a distinct object to be aimed at in educa- 
tion; the second attends but little to special operations. 
‘« The former recommends special or technical instruction with 
a direct view to material success in a particular business, the 
direct aim of the latter is to educate and strengthen each indi- 
vidual mind. The essential differences between them arise from 
the fact that they look at the question from opposite sides, and 
respectively put forward what they see most clearly.” 
After this sketch of the outline of the characteristics of the two 
great parties, Professor Williamson describes some results of the 
arrangements recommended by them respectively. The great 
aim and object of science is to systematise our knowledge ; and 
the discovery of an idea which helps to arrange any considerable 
number of facts in such a manner as to facilitate their apprehen- 
sion, is the highest result of scientific work. We are then led 
in an admirable manner from the periodical disappearance of the 
sun to the law of gravitation as a model of scientific work. But 
it must not be supposed that the application of science to prac- 
tical purposes is the greatest reward of scientific work. We read 
on page 12— 
‘*To any one possessing a clear and vigorous mind, the ac- 
quisition of an idea which helps to explain things is a source 6f 
intense pleasure. He feels that it enlarges the scope of his mind, 
and gives him new power; and when facts, previously unintelli- 
gible, are explained by the aid of such an idea, they immediately 
acquire vivid interest and special value to his mind ; such facts 
seem to gain life by acquiring an intelligible place in the system 
of nature. 
“T believe that the triumphant feeling of the enlargement of his 
faculties which is experienced by a real student in the acquisition 
of any new law or principle of nature, is the most direct and 
vivid reward of his labours. The best and truest, as well as the 
most rapid progress in study, is made for the sake of that reward. 
Whoever has once enjoyed it will gladly seize any opportunities 
of wrestling, as far as his powers permit, with new difficulties, 
and mastering new ideas. 
‘Tt has been said that the happiness of an individual results 
from the due exercise of his various facult es, and this is surely 
not le st true of the highest faculties of the mind ; certainly 
those who have the power of understanding the wonders of nature 
derive great hap, in ss from learning to employ it. It is like the 
pleasure which a min of healthy an1 vigorous france experiences 
i1 climbing a mountain peak, and in enjcying, in proportion as 
he rises, a wider and more commanding view of things below.” 
Our space does not permit us to follow the author into the 
study of the conditions under which science flourishes, and does 
most effectively the good which it has to do, and we must content 
ourselves with a quotation of his description of the usual results 
which follow a system of special professional pupilage : 
“* But it often happens (page 15) that aman learns thoroughly 
the particulars of a business, as practised in some one successful 
case, and although he has sufficient capital and industrious 
habits, fails to realise similar results elsewhere. 
‘« For instance, he has learnt and practised the management of a 
particular farm, and then takes a lease of one in another district. 
Ife purchases implements exactly similar-to those which he has 
been using, and gets sheep and cattle of the same breeds. He 
ad pts the same rotation of crops, and spares no pains to make 
everything go on precisely in the same way as that to which he 
has been accustomed. 
‘¢ His first year is unprofitable ; but he looks forward hopefully 
to better results, when things will have got into better working 
order. But the second and third year only bring more losses, 
and he is ultimately compelled to give up the farm. 
‘©The next tenant is perhaps a man who has learnt the 
management of an adjoining farm, wh'c’: happen2d to be in siz», 
in soil, &c., very much like it, He uses ploughs and other im- 
plements which have been found to suit the soil, and gets breeds 
of sheep and cattle which thrive in that put of the country. He 
adopts the same rotation of crops and system of manuring which 
is customary in that district, and carefully imitates what he hal 
seen to succeed, under conditions similar to his own. ‘The re- 
sult s hat he goes onsteadily year after year making a fair profit. 
** Both of these men were mere servile imitators of what they 
had seen, and both had been taught to believe that a practical 
man ought to be nothing more, and that all theories are 

dangerous. Yet one failed while the other succeeded. We 
ought not to be surprised at the failure of the one, so much as at 
the success of the other, which was due to the exceptional cir- 
cumstance of his finding a farm which admitted of being profit- 
ably managed upon exactly the same system.” 
Men of business, in the opinion of our author, ought to 
have not only a knowledge of things, but also of principles ; and 
they must be able to use their knowledge of these things and 
principles for the purpose of bringing about special results ; 
in fact they must have a knowledge of the laws of nature, and 
skill in the methods of applying that knowledge to experimental 
purposes. ‘Their power of bringing about the material results 
from which they derive profit is proportional to the amount of 
such knowledge and skill which they possess. 
And here we must break off our account of an essay which, no 
doubt, will greatly help to clear up our ideas about scientific and 
technical education, 


ZOOLOGY 
Researches on the Amcébze 
THE minute masses of protoplasm termed Amcebe have 
been recently examined by M. V. Czerny, in relation to their 
resistance to reagents, and his results have been published in 
Schultze’s *‘Archiv fiir Mikroscopische Anatomie,” p. 158. He 
finds that the power of resistance to the action of solutions of 
common salt varies considerably in different individuals, In 
solutions containing one part to four hundred of water none 
died, but in those containing one to three hundred many died ; 
whilst others, especially the quiescent ones, still lived in solutions 
containing one per cent., or more. None, however, survived 
when suddenly placed in a two per cent. solution. It is interest- 
ing to observe, however, that these lowly organised beings 
possess a certain adaptability to external conditions—a power of 
acclimatisation as it were, enabling them, if these conditions 
undergo slow alterations, to accommodate themselves to their new 
and modified surroundings. Thus, if the strength of the solu- 
tion were gradually raised, it was found that some Amecebze 
could continue to exist in solutions of four per cent. of salt. M. 
Czerny corroborates the statements already made by Kiihne, 
that, on exposure to weak saline solutions, Amoebze thrust forth 
numerous extremely delicate processes resembling cilia, and 
that they undergo fission. It is worthy of remark that the 
partially double contour of the Aseda bilabiata, which has led 
to the admission of a double contoured membrane in this species, 
is resolved, when examined with a No. 10 Hartnack immersion 
lens, into a number of closely aggregated, extremely minute 
toothlets, which, like the stinging cells, cover the whole surface 
of the body. 
M. Engelmann has made some observations on the electrical 
excitation of the Amoeba of the Arcella in the fifth volume of the 
** Nederlandische Archiv voor geneesen Natuur kunde,” p. 28. 
His investigations were conducted in a moist gas chamber, with 
unpolarisable electrodes, the stimulus consisting of a single open- 
ing induction shock. Ia Amada diffluens, as Kiihne had showed 
previously, the results of the excitation differ according to whether 
the individual is in the active or in the quiescent condition. In 
the former condition, that is, when the animal is elongated or 
club-shaped and homogeneous, and its protoplasm seems to be 
flowing continuously in one direction, a very slight stimulus re- 
tards or altogether arrests the current, though it speedily recom- 
mences, the period of arrest not exceeding at most five seconds. 
If, however, the stimulus has been a little stronger, in addition to 
the arrest of the protoplasmic movements, a condensation and 
shortening of the whole animal occurs, and at a subsequent period 
perfectly transparent projections form in the anterior part of the 
body, into which the highly granular protoplasm streams until the 
original form of the Amoeba, which sometimes moves forward 
with great rapidity, is re-established. The length of time occu- 
pied in these changes may amount with tolerably strong currents 
to about from one to two minutes. If the excitation be applied 
to the quiescent animal, the protoplasmic movements first cease, 
the mass assumes the spherical form, but instead of remaining 
quiescent, it now begins to move from place to place, in which 
active condition it may remain for a long time. From these ex- 
periments, and from others performed upon specimens of Arcella, 
containing air-vesicles M. Engelmann draws the conclusion that 
protoplasm, in consequence of electrical excitation, transitorily 
assumes the mechanical properties of a fluid, 
—— 
