in fact, short of the absolute certainty of their resulting in the prevention of a larger quantity of equally acute suffering. Practically, such certainty it is impossible to predict for any experiment. Consequently, I hold that to inflict very extreme and prolonged suffering is not justifiable at all. I consider that some continental vivisectors have inflicted tortures which would have been utterly inexcusable even if the benefits to be derived therefrom were likely to be very considerable, but from which, as a matter of fact, the results obtained were exceedingly trivial; and while, as I have said before, I think anti-vivisectionist writers have tried to produce an impression in the public mind that the same sort of things are being done in England to-day, on the other hand, I think the defenders of vivisection have been very unwise not more prominently and more strenuously to condemn the cruelties which have been perpetrated in the interests of Science in France and Italy. And although I believe that the sympathy of Englishmen, as a class, for lower animals is so great, that under no circumstances, whether there were legal restrictions or not, would gross cruelties be practised in this country by really competent experimenters; still, much needless suffering might be inflicted on animals by the clumsy experiments of incompetent persons if there were, what Mr. Hutton so grimly calls, a" free vivisection table." I therefore thoroughly approve of the practice of vivisection being restricted to licensed persons; and no person ought to receive a license who has not had such previous training as would ensure his being competent and skilful.

Further, I agree with the principle of the Act of 1876, that it should not be left altogether to an individual physiologist to determine how much suffering it is justifiable to inflict in order to solve a given problem; at all events, in those exceptional cases where it is proposed to cause a considerable amount of pain; nor do I think that the majority of practical

physiologists would object to submitting their proposals for experiments to a suitable authority for approval before carrying them out.

There is one absurd feature of the Act, however, viz., its leaving the Home Secretary to decide, without recognised skilled assistance, on the propriety of granting or suspending licenses, and on the relative importance of suggested investigations relating to such highly technical matters as the problems of physiology and pathology.

There can be no doubt that the Home Secretary ought to be relieved of his duties in relation to the Act of 1876, or, at all events, if he retains his responsibility as administrator of the Act, the investigation of the claims of persons to receive licenses, and of the justifiability of all proposed experiments which would be likely to give any material amount of pain, should be in the hands of a competent Board of Administration.

I cannot now discuss how far the details of the Act require amending. My impression is that its regulations are too complicated and its methods too cumbrous; but that is a small matter compared with the necessity for the Home Secretary being either replaced by, or associated with, a suitable Board for administering the Act in detail. If a Board of this kind could be so constituted that both the medical profession and the public would be satisfied to leave in its hands the regulation of scientific experiments on animals, it might be fairly hoped that the subject of vivisection would be allowed to subside into quietude; that the various antivivisectionist societies would cease to be able to extract from an emotional but unreflecting public that pecuniary pabulum which the prolific character of their literary productions must require; and that those who have the talents and the opportunities of carrying out researches in practical physiology, or in experimental pathology, which has been rightly described

as "the youngest and most brilliant branch of medical science," might do so without exposing themselves to be held up to public reprobation as heartless torturers, or their experiments to be described in widely-disseminated pamphlets as "the bloody infamies of the vivisecting trough."

It might be fairly hoped, too, that the subscribers to hospitals would no longer be bullied into withdrawing their subscriptions because one of the members of the medical staff might hold a license to perform experiments; and that ladies would be able to advertise for strayed dogs without being inundated with nauseous stories about the horrors of vivisection.

Such devices are utterly unworthy of an honest desire to settle an important question of practical morality; and however much my hearers may differ from me in their conclusions regarding the justifiability, under restrictions, of scientific experiments upon living animals, I trust they will, whenever occasion may arise, do their best to discourage all unfair methods of appealing to the passions and prejudices of people rather than to their sober reason; for, in the long run, the question will have to be settled "on the best and surest foundations," viz., accurate knowledge and dispassionate judgment.

THE PRIMARY COLORS.

ABSTRACT OF PAPER READ BY G. H. MORTON, Jun.

Or all the interesting phenomena concerning color, resulting from recent scientific researches, probably the hypothesis that red, green and violet are the three primary color sensations, attracts most attention, because of its apparent antagonism with the fact that red, yellow and blue are the three primary colors of pigments.

All colors are really sensations, caused by the action of light on one of the divisions of the retina, the so-called layer of rods and cones. It has only recently been discovered, however, by Professor Max Schultz, that both the rods and the cones have each their peculiar function, and though probably both serve as elements of light, it is more especially the function of the rods, whilst the perception of color is due, possibly exclusively, to the cones. These cones appear to be divided into three sets; one set being stimulated by the strongest vibrations of light produces the sensation of red, another set acted upon by the vibrations of medium strength produces green, and the third set responding to the short and weak vibrations produces the sensation of violet. Red, green and violet are therefore termed primary colors. Intermediate vibrations affect two sets of cones simultaneously, and consequently produce compound or secondary colors. Upon the three sets of cones being excited together, in their proper proportions, the sensation of white is the consequence. If this theory be true, we may assume the existence of a color-sense wherever we find the cones, and to mark it absent wherever they are absent. A defect in their arrangement probably accounts

for color-blindness. It is well known that color-blind persons are usually insensible to the stronger, red-producing, vibrations, though cases occur when they are blind to other colors and keenly sensible to the red; indeed, the partially color-blind, as a rule, appreciate more intensely the colors they are able to perceive than persons possessing the normal sense of color. The number of persons affected, more or less, with color-blindness is surprising; according to Professor Rood it has been estimated that in England about one person in every eighteen has an imperfect color-sense, though it is remarkable that the affliction is almost exclusively peculiar to the male sex, women being comparatively free from it. Often the color-blind are for years unconcious of their defect, and it is very difficult to demonstrate the fact to them. When we consider the theory of the rods and cones, and are aware that a slight difference in their arrangement causes a proportionate difference of colorperception, and knowing that we are all subject to a slight difference, it would appear probable that each individual is affected by the vibrations of light to a different degree, or, in other words, that possibly no two persons see colors exactly alike.

Color combinations may be demonstrated in different ways; perhaps the simplest is by employing two lanterns, and projecting colored light from both on to a white screen. The two color-discs, when superposed, produce one color; the sum of the two separate discs.

Taking the

primary colors, red and green produce the sensation of yellow; red and violet produce pink; green and violet produce greenish-blue.

The resulting colors, yellow, pink and greenish-blue, are the secondary colors, and it follows that the brightness, or lightness, of any of these colors must be greater than that of any of the primaries, because of the nearer approach to