THE DANYSZ EXPERIMENTS.

Lyttelton Times, Volume XCVI, Issue 14386, 31 May 1907, Page 8

THE DANYSZ EXPERIMENTS.

(" Canterbury Times.") Dr Danysz has completed six months of experimenting with the rabbit virus on Broughton Island and lias left for France. Ho has stated publicly that ho is dissatisfied on account of opposition he has had to •encounter, and may return if given an opportunity to carry out his work under more favourable conditions. Precisely what form this opposition took has not been made clear, but the position as a whole is far from satisfactory from the point of view of those who hoped' the Doctor would provide an effective solution of the rabbit problem. Prior to his departure, Dr Danysz issued a report upon the results of his experiments to date, from which the following main points are extracted:— The objects of the experiments made were to ascertain—(l) If "the rabbit virus can give better results than the means of rabbit destruction hitherto employed; (2) If the rabbit virus can be used on stations infested with rabbits without danger to man and the domestic or wild animals. The report states that the first of these questions may be considered as solved, as far as it can be under the special conditions of climate and soil found on the island, which will rarely be found on the mainland As to the second question, the report states that very reassuring experiments have been made; but it was thought necessary to expose domestic animals to contagion, for a year, as some contagious diseases are more virulent at some seasons of the year than at others. Cattle, sheep, pigs, goats, kangaroos and poultry were submitted to contagion by eating fodder sprinkled with the virus, and by direct infection, but in not a, single instance was the disease communicated. Of the effect on rabbits it was proved that all of them fed on. fodder sprinkled with the virus died. The report states: —" The total result of four experiments is that 72 rabbits infected with the virus all died themselves, and gave the disease to 193 out of 307 healthy rabbits with which they were put; in other words, one rabbit infected directly by the virus has given a mortal disease to' about three-others (2.68 exactly). . . . Tho observations made on Broughton Island, as well a 3 in tho Board of Health laboratory, enable us to hope that on the mainland, by the help of different climatic conditions, the disease will be more contagious than on the island." The preparation of the virus can be easily made by tho stockowners 1 , and on this head Dr Danysz says:—" When the time cornea to use these methods, all interested will get full particulars and instructions on this subject'."

The publication of the report has produced varied criticisms from Australian journals. The " Australasian " favours the Doctor's treatment to this extent: Six months' experiments with the rabbit virus have proved to ©very unprejudiced mind that the virus is harmless to man and to all the domestic- animals, and that it is a better remedy for the rabbit pest than any yet employed. It is to be regretted that Dr Danysz has met with meet determined opposition in carrying out his experiments, which are of such vital importance to the stock-owners of all Australia. It is natural that all who are interested in what is miscalled the rabbit industry should be violently opposed to any means, likely to prove successful, of extirpating, or even greatly reducing, the rabbits now infesting the land. Oddly enough the representatives of M. Pasteur met with oven a stronger opposition when they introduced preventive means for rendering live stock immune to the disease of anthrax.

The Sydney "Stock and Station Journal" is by no weans bo optimistic, and gives voice to the views of many Australian pastoralists thus:—v There is on© Hct. that stands out very

clearly, and that is the fact that Dr Danysz does not expect that the pas-*, teurella is going to exterminate rabbits, j It is not so much a sweeping disease as > a superior poison, the chief advant-. '■ ages of pasteurella being that it will not kill sheep,_ as phosphorised pollard will, or arsenic, or strychnine. But" the pasteurella, needs to be constantly renewed. But nobody is very certain , as to the nature of a pasteurella; Dr ' Danysz says that: "If in laboratories or elsewhere rabbits are found diseased or dead xvith a pasteurellosis, it would not be possible to tell at once whether this pasteurellosis is specific for the> rabbit, or had previously been derived from a sheep a pig or' a fowl." If the pasteurella which kilLs a fowl will kill a rabbit, or vice versa, then why not kill a sheep? The swine fever is tha product of a" pasteurella, and it would l bo a terrible thing if the sheep pasteuiv ella suddenly became virulent, and fatal to our flocks. Dr Danysz 6ays, in his report, that—"lt is very probable that by keeping on passing always tho same culture from one rabbit to another, one will make it more and mora virulent and specific for the rabbits." But a change of virulence means a change of character in the microbe, and if the wretched germ is thus gifted with the capacity for variability, and is so capable of development, and is so like the sheep pasteurella, are we. not running a terrible risk? This is playing with fire indeed, and monkeying with a disease «which contains almost infinite capacity for evil. Dr Danysz wants six months' trial on tho island under the supervision of Mr Latapie and Dr : Tidswell, and some people are complaining about the lons, time the experiment is going to take. Far better that it should take sis years instead of six months, and be quite safe. Disease is a dangerous thing to fool with. We introduced rabbits with a light heart, and look at them now! They are actually ruining us. As soon as the dry days come w 6 shall have to reckon with tho vermin. Wo introduced thistles, too, and foxes, and starlings, and the burrs introduced themselves. The harmless blackberry, and the pretty ill-smelling lantana. are curses to us but pets elsewhere, and they came to us because of our ignorance. And now we are in a hurry to introduce a strange disease. The only one who appears to understand tho subject fully is Dr Danysz. He tells us that chicken cholera is caused by a pasteurella, and he says: " Since "the chicken cholera is very virulent to rabbits, the epidemic may also spread to tho latter, at the same time or later. In this case tho microbes, though, isolated from rabbits dead from infection, are not specific for rabbits; they will kill fowls also because, they are really : the fowl pasteurellosis." And yet we.' are howling for a trial of this disease "in the open." Would it not be wiser to be calm, and leave the matter in the' hands of the committee? Since the foregoing was written a cablegram has announced that the South Australian Commissioners have reported adversely on the Danysz virus experiments, and state that it would be a waste of time and money for Pro- 1 , fessor Danysz to proceed further. Unless the remaining six months of' experimenting which is to be supervised by Commonwealth experts produce.*? more definite conclusions than those so far obtainable it would appear that tho ordinary methods of poisoning, netting, " etc., will have to be proceeded with vigorously by those who are afflicted with the rabbit curse.