104 
The Tick Trouble. 
INOCULATION TESTS.—DR. HUNT'S EXPERIMENTS.—HIGHLY 
VALUABLE RESULTS.—A MOST INTERESTING REPORT.— 
INOCULATION AT GRACEMERE. 
Tue following is the latest progress report received by the Chief Inspector of 
Stock from Dr. J. S. Hunt, who is carrying on experiments with reference to 
tick fever in the vicinity of Hughenden :— 
“Tn view of the desirability of obtaining definite evidence as to the safety 
and efficacy of inoculation with the blood of a recovered animal as a means 0 
protecting cattle from tick fever, the following experiments, recently performed 
here, are, I venture to think, of sufficient interest to warrant their being at once 
communicated for the information of your Board. ; 
“The experiments in question were designed to ascertain— 
“1, The amount of immediate danger incurred in inoculating clean cattle 
with various quantities of blood from a recovered beast. ; 
“9. The protective efficacy of such inoculations—(a) against virulent tick 
infection; (4) against injections of virulent blood from an acutely diseased 
beast. 
' 3, The protective efficacy of small daily doses of arsenic—(a) against 
virulent tick infection ; (b) against injections of blood from an acutely diseased 
t. 
“Tt will be at once observed that these experiments, so far as inoculation 
with the blood of a recovered beast is concerned, are on the same lines as those 
instituted at Mundoolan. From the scientifie standpoint they are decidedly 
inferior to the Mundoolan experiments, not only on account of the smaller 
numbers dealt with, but because the absolute cleanliness—past and present— 
of cattle within the infested area is always more or less open to question. On 
the other hand, from the purely practical point of view they are, I think, of 
considerable interest, because they were carried out under precisely those 
conditions in which protective treatment is mostly called for—namely, in the 
case of cattle yet unaffected with disease in the tick-infested areas, and cattle 
threatened on the borders of those areas. In neither of these cases can the 
_absolute cleanliness of the cattle be assured, nor, so far as the interests of the 
owners of such stock is concerned, is this of any importance, because, whether 
perfectly clean or not, such cattle are certainly susceptible to the disease, and 
therefore require protection. 
“Tt may perhaps be suggested that for experimental purposes—to deter- 
mine the actual value of any given method of inoculation—the bare possibility 
of any of the cattle employed being partially or even wholly immune from some 
previous tick infection is an absolutely fatal objection to the validity of any 
deductions that might be drawn from such experiment. But as against this it 
must be remembered that all the cattle employed were of the same class, and 
drawn from the same locality ; and even though a percentage of them might 
possibly have been partially or wholly immune, the error from this cause was 
equally distributed over the whole lot, and would not affect the comparative 
results as between those inoculated, those treated with arsenic, and those used 
as ‘ controls.’ 
“The conditions requisite for carrying out the proposed experiments 
were :—l. Clean cattle, or cattle from a locality where no disease had been. 
2. An.animal that was known to have had the disease and recovered (from 
