COMPARATIVE MERITS OF VACCINATION. 
589 
fatory apologetic remarks, Dr. Martin proceeds to discuss the 
question—one of paramount importance —“ Whether the 
virus obtained by the inoculation of bovine animals with the 
virus of original cowpox induces the development of Vaccinia 
of greater perfection, and, therefore, of probably more pro¬ 
tective efficacy than that obtained by the transmission of the 
same disease on a series of human subjects?” The key-note 
of all legal enactments, the opposition to such laws, the oft- 
related results of smallpox epidemics, the origin of anti¬ 
vaccination leagues—all include the pith of this query. But 
the answer to it—a decided and truthful answer—is difficult 
to reach. If the only reliable test, post-vaccinal inoculation 
with variolous lymph, could be applied, and better, if it could 
be repeated at intervals of time, indubitable and veritable 
results would be obtained; but in the absence of such we 
must draw r our inferences as carefully as possible from nature's 
experiments during smallpox, epidemics, and from such in¬ 
direct data as the role of phenomena furnished by the several 
varieties of vaccination and the cicatrices they produce may 
furnish. 
An important point stated by our author, and it is one too 
frequently overlooked by vaccinators, is that Jenner always 
maintained febrile reaction to be “ the only perfect proof of 
constitutional affection, and absolutely essential to the perfec¬ 
tion of the prophylaxis. Without it he pronounced a vaccin¬ 
ation merely local and quite or nearly without value.” This, 
moreover, has always been felt to be a drawback attached to 
the continuous transmission of vaccine lymph through the 
human subject. To remedy it retro-vaccination (or the 
transmission of vaccinia through the bovine species at intervals 
before its transference to man) was strongly advocated, and 
with this object retro-vaccination is still carried on in Bavaria 
and some other countries. But the difference of opinion as 
to the utility of retro-vaccination has failed to encourage an 
extensive trial of the method. 
Animal vaccination, or heifer-transmitted cowpox in¬ 
oculation, was inaugurated in America during September 
1870 by Dr. Martin, and in his report we have the observations 
he has made, and the results at which he has arrived, from a 
continuous and careful study of this mode of vaccinating since 
that time. During twenty-five years prior to this date, he 
had “ had constant experience” of the Jennerian method, 
and after receiving the “ animal lymph” from M. Depaul of 
Paris in September 1870, he continued for some time to 
vaccinate children with humanised (National Vaccine In¬ 
stitution of England) lymph on one arm and with heifer 
