April 5, 1883 | 
NATURE’ 
545, 
ii. Zo obtain direct and exact knowledge of the processes of | 
disease. 
The following examples may be cited :— 
(1) Experiments relating to the nutrition of the body and the 
maintenance of its constant temperature constitute the basis of 
the existing knowledge of fever. 
(2) Experiments relating to the mechanism of the circulatlon, 
and to the influence of the nervous system thereon, have served 
to explain the nature and mode of origin of the various forms 
of dropsy 
(3) Experiments as to the effect of plugging arteries (Em- 
bolism) have afforded explanations of diseased processes pre- 
viously not understood, and in particular of many obscure cases 
of sudden death. 
(4) Experimental investigations of the functions of the liver 
and other secreting glands have materially advanced our know- 
ledge of diabetes and of the affections known as Bright's 
disease. 
(5) Knowledge gained from experiments relating to the mode 
of action of the muscles, and of the nervous system which 
regulates them, constitutes the basis of the pathology and 
diagnosis of convulsive and paralytic diseases. 
(6) Experiments on animal grafting and as to the nature of 
the processes by which wounds are healed and injured parts 
restored. Among the best known are those which relate to the 
mode of repair of fractured or otherwise injured bones, par- 
ticularly the researches of Duhamel (1740), Sir Astley Cooper 
(1820), and Syme (1831). In recent times such inquiries have 
been pursued much more completely by Ollier and others, and 
with practical results of ever-increasing value. 
(7) The dangerous form of blood poisoning after operations 
has been investigated by strictly physiological experiments, with 
the result of almost complete protection from it. 
(8) Researches into the origin and nature of inflammation, by 
Redfern, Cohnheim, Von Recklinghausen, and others, have 
been of necessity conducted by means of experiments on 
animals, and have proved of great practical value. 
(9) Our recently extended knowledge of the locality of diseases 
of the brain, and of their accurate diagnosis and treatment, has 
been due, partly to clinical observations, partly to pathological 
investigations, but also, and not least, to direct experiments 
upon the lower animals. 
iii, Zo test various remedial measures directly. 
The utility of the greater number of the older remedies and 
methods was first learnt empirically : but many of them were 
not applied to the best purpose until they have been investigated 
by observations on the lower animals. As regards the remedies 
and appliances of modern times, they have, in almost every 
instance, been investigated first and brought into use afterwards. 
For example ;— 
(1) Subcutaneous injection was used in the laboratory for 
years before it was applied in practice. 
(2) The useful property of the well-known anodyne chloral 
hydrate was first investigated in the laboratory, and then intro- 
duced into practice. ; 
(3) Pepsin and pancreatin were known for years as physio- 
logical agents before they were applied in practice. 
(4) The action and mode of administration of such important 
new drugs as nitrate of amyl, physostigma, and the anzesthetic, 
methylene, were discovered entirely by physiological experiments. 
(5) The better appreciation and more useful application of 
some of the most valuable remedies were gained by experiments, 
such as those by Traube on‘digitalis, by Magendie on strychnia, 
and by Moreau and others on saline purgatives. 
(6) The application of various practically useful methods of 
checking hemorrhage was tested upon animals before being 
tried gn human beings, with the result of saving innumerable 
lives, 
(7) Similar preliminary trials of subcutaneous and other 
operations, especially those of tenotomy, have helped in the 
relief of numerous deformities; while the trial of such for- 
midable operations as excision of the kidney and tentative im- 
provements in ovariotomy have led to some of the most brilliant 
results of modern surgery.’ 
In cases where new drugs are to be introduced, or new operative 
methods tried, the first experiments must be made either upon 
t See an article in Narure, vol. xxv., p. 73- 
® See an article in the Nineteenth Century for December 1881, p. 926. 
3 See a paper by Mr. Spencer Wells, Trans. Internat. Med. Congr. vol. 
il, p. 226. 
living animals or upon living men. Where circumstances ex- 
cluded the former alternative, members of our profession have 
not hesitated to make themselves the subject of often hazardous 
experiments : but happily, in most instances, the sacrific: of a 
= guinea-pigs or frogs will suffice to help in saving human 
ife. 
iv. Zo ascertain the means of checking contagion, and pre- 
venting epidemic disease both in man and in brutes 
An experiment of this kind, inoculating the udder of a cow 
so as to produce a vaccine pustule, was one of the links in the 
great discovery of Jenner. Among more recent examples may 
be mentioned :— 
(1) The experimental investigations of the last fifteen years, 
as to the origin and nature of the infective diseases which spring 
from wounds and injuries (pyzemia and septiczemia), the results 
of which constitute the basis of antiseptic surgery.” 
(2) Th discovery by experiments of the infective nature of 
tuberculosis (1868), of its relation to chronic inflammation, and 
finally of the dependence of its infectiveness on a living parasitic 
organism (1881). 
(3) Discovery of the mode of origin, and consequently of the 
prevention, of various parasitic entozoa (hydatids, trichina) 
which infect the human body, by inference from investigation of 
their development in the bodies of animals. 
Among diseases of animals may be mentioned :— 
(1) Silkworm disease, which has been brought completely 
under control by the experimental discoveries of Pasteur. 
(2) Small-pox of sheep, against which preventive inoculation 
has been long used. 
(3) Cattle-plague, the prevention of which is entirely founded 
on the knowledge of its mode of spreading gained by ex- 
periment. 
(4) Pleuro-pneumonia of cattle, and foot and mouth disease, 
of which, although experiment has not as yet yielded a satis- 
factory mode of prevention, it has furnished exact knowledge 
as to the method of its propagation. 
(5) Splenic fever of cattle, and the analagous diseases of 
horses, sheep, and other animals, against which experiment has 
recently furnished a mode of prevention, now successfully used 
in countries in which this disease has most fatally prevailed, 
particularly in France. 
(6) Farcy and glanders, the early detection and prevention of 
which has been greatly promoted by experiments. 
v. Lor instruction. 
It is not necessary to insist on the well-known difference 
between book-learning and demonstration. Like chemistry, 
physiology must be taught practically if it is to be tauzht well, 
and it is necessary that all students of medicine to whom the 
care of the human body will be intrusted should have a practical 
and thorough familiarity with the most important functions of 
that body. For this purpose no painful experiments are neces- 
sary, and none are performed in our medical schools and 
colleges. Most of the demonstrations of what is called ‘ prac- 
tical physiology ” are demonstrations of the microscopical struc- 
ture of the tissues, or of their chemical properties and processes, 
or of their physical endowments, and the remainder apply to 
the organs of insensible or recently killed animals. Whether 
the occasional repetition of an experiment of great importance, 
and involving very little pain, would be morally justifiable may 
admit of question; but, as a matter of fact, it is not and cannot 
be done. Apart from the provisions of the Act, this question 
was decided long before by the resolution quoted above. 
vi for the detection of poisons. 
The fact that some of the most subtle and dangerous poisons 
cannot be certainly identified by ordinary testing (7.e. by recoz- 
nition of their physical and chemical properties), is well known. 
In such cases the physiological test, or the effect of the poison 
upon the lower animals, is the only means by which the guilt of 
murder can be brought home to a criminal, or the innocence of 
a wrongfully accused person established. This, like many other 
scientific facts, has been disputed by ill-informed persons: but 
it is beyond serious question.? 
* For details on this part of the subject, see the Address by Mr. Simon 
C.B., F.R.S., entitled ‘‘ Experiments on Life as fundamental to the Science 
of Preventive Medicine.”” (‘Transactions .of the International Medical 
Congress. 188r.’’) 
? For details, see a paperin the Wineteenth Century for March, 1382, by 
Mr. George Fleming, President of the Royal College of Veterinary Sur- 
geons : ‘‘ Vivisection and Diseases of Animals.”’ 
3 See on this subject a paper by Prof. Gamgee, of Owens College, ‘The 
Utility of Physiological Tests in Medico-Legal Inquiries.” 
