DISEASE-GERMS. 253 



view to the further experimental testing of the poisonous effect pro- 

 duced upon the grass which will grow over their graves. But the re- 

 sult, says the reporter of the " Times " (June 2d), " is already certain ; 

 and the agricultural public now know that an infallible preventive ex- 

 ists against the charbon-poison, which is neither costly nor difficult, as 

 a single man can inoculate a thousand sheep in a day." I have since 

 learned that this protection is being eagerly sought by the French 

 owners of flocks and herds ; and, if any severe epidemic of the same 

 kind were to break out in this country, our own agriculturists would 

 probably show themselves quite ready to avail themselves of it. To 

 the " wool-sorters " of Bradford it must prove a most important boon, 

 if they can be led to understand its value. 



That this is not to remain an isolated fact, but will be the first of a 

 series of discoveries of surpassing importance (some of them already 

 approaching maturity), is shown by the fact that Pasteur has found 

 himself able to impart a like protection against fowl-cholera by " vac- 

 cinating " chickens with its cultivated bacillus. 



These wonderful results obviously hold out an almost sure hope of 

 preventing the ravages, not merely of the destructive animal plagues 

 that show themselves from time to time among us, but of doing that 

 for some of the most fatal forms of human infectious disease which 

 Jennerian vaccination has already done as shown by Sir Thomas 

 Watson in these pages for what was once the most dreaded of them 

 small-pox. It is unfortunately too true that, with the reduction of 

 small-pox mortality, there has been an increase in the mortality from 

 measles and scarlatina exceeding that which increase of population 

 would account for, the number of deaths in England and Wales from 

 the former of these diseases frequently exceeding 10,000 in the year, 

 while the annual mortality from the latter averages neai'ly 20,000, 

 sometimes exceeding 30,000. It scarcely seems too much to expect 

 that before long, as Professor Lister last year suggested, " an appro- 

 priate ' vaccine ' may be discovered for measles, scarlet fever, and other 

 acute specific diseases in the human subject" ; for already, as I have 

 been informed by one of the most distinguished of the United States 

 members of our Congress, researches have been there made, with very 

 promising results, on the " cultivation " of the diphtheritic virus the 

 mortality from which, in England and Wales, during the last decade, 

 has averaged nearly 3,000 annually, being, for the seven years, 1873-79, 

 half as great again as the mortality from small-pox during the same 

 period. 



Another important line of inquiry, which was supposed by many 

 able pathologists to have been closed by the negative results of pre- 

 vious investigations, has now to be reopened under the new light shed 

 upon it by Pasteur's discovei'ies : I refer to the relation between cow- 

 pox and small-pox. It is well known that Jenner himself, struck with 

 the fact that the protective influence of successful vaccination against 



