^pril 2, 1886.] 



SCIENCE. 



297 



>uch attempts as those of the eminent chemist 

 ind philanthropist. The sober-minded man should 

 snconrage every form of research designed to 

 promote the interests of humanity ; but he should 

 it the same time reserve his judgment until suffi- 

 cient data are at hand for reaching a well-ground- 

 ed conclusion. 



The efficacy of any method of treating hydro- 

 phobia must be extremely difficult to test in a 

 way which shall be at all conclusive. The first 

 difficulty we meet in reaching a conclusion arises 

 from the extreme rarity of the disease. The 

 number of readers of these lines who have ever 

 had personal knowledge of a case of hydrophobia 

 is probably very small. In the returns of the last 

 census eighty deaths are reported from this cause 

 in the United States. But we should regard this 

 number as an extreme limit rather than as a 

 well-established quantity, owing to the possibility 

 of other forms of disease being mistaken for 

 hydrophobia. On the other hand, the number of 

 persons who are actually bitten by clogs which, 

 for aught they know, might have been rabid, is 

 very great. It is certainly to be estimated by 

 thousands, and perhaps by tens of thousands. It 

 becomes apparently much greater when, as during 

 the past year, the public mind is excited on the 

 subject. In such a case it is difficult to ascertain, 

 to the entire satisfaction of the injured person, 

 that any dog which may have bitten him was not 

 rabid. The result is, that it is rarely possible to 

 select any injured person as probably being inocu- 

 lated with rabies. Of the persons brought into an 

 institute for treatment, it may be assumed that 

 only a small percentage would, under any circum- 

 stances, develop ^he actual disease. 



Pasteur's supposed success cannot, therefore, be 

 established as a fact until we have more complete 

 evidence of the circumstances attending the in- 

 juries, and especially of the rabid character of 

 the animals which have bitten his patients. Even 

 ' of the well-established cases of bites by rabid 

 jdogs, only a minority ever develop into actual 

 rabies, and this minority may require many 

 months for the graver symptoms to appear. The 

 Ifirst certain conclusion must therefore be founded 

 Ion statistics in which the evidence that the ani- 

 mal was rabid shall be conclusive, and in which 

 every result shall be included. A table showing 

 I the termination of all cases treated, and of all 

 similar cases not treated, will ultimately be con- 

 clusive, and nothing less will serve the purpose. 

 The efficacy of the treatment cannot be disproved 



by occasional cases of failure, unless it is shown 

 that these cases approximate in number those in 

 which no fatal symptoms are ever developed. 

 This also must depend upon the results of a 

 statistical investigation. 



No doubt, a profound impression has recently 

 been made by the failure of the treatment in the 

 cases of the party of Russians bitten by mad 

 wolves ; but this failure only shows that the treat- 

 ment may fail in such extreme cases as these, 

 which seem to have been unusually severe. It is 

 quite conceivable that a process which would be 

 entirely successful in cases so mild as to require 

 several months for their development would prove 

 useless when the quantity of virus injected was 

 so great as to lead speedily to a fatal termination. 

 It is significant that the first Russian to succumb 

 was bitten by an animal so ferocious that one of 

 its teeth was left deeply embedded in the flesh of 

 its victim. 



If the final conclusion should be against the 

 efficacy of inoculation, are we to denounce the 

 propounder of the treatment as a pretender ? By 

 no means. He will still be entitled to all the 

 credit which society owes to a man who makes an 

 honest attempt to promote its welfare. The char- 

 acter of the great experimenter is above sus- 

 picion ; and the knowledge which he acquires, if 

 not useful hi one direction, may be useful in an- 

 other. Let us, then, wish him well, and, if he 

 fails, let us still award him the credit due to the 

 spirit which inspired his efforts. 



THE MALARIAL GERM OF L AVER AN. 



During a recent visit to Rome, the writer had 

 an opportunity to see, for the first time, a most 

 interesting blood-parasite, which was first de- 

 scribed several years since by Laveran, a medical 

 officer in the French army. Extended researches 

 made in Algeria had convinced Laveran of the 

 constant presence of this parasite in the blood of 

 persons suffering from malarial fevers, and that 

 it is not found in the blood of healthy persons, or 

 in that of those suffering from other diseases ; 

 also that it disappears from the blood under the 

 administration of quinine, which is recognized as 

 having a specific curative effect in diseases of this 

 class. 



There are many circumstances connected with 

 the causation of the malarial fevers which make 

 it appear probable that they are due, either di- 

 rectly or indirectly, to a living organism which 

 finds its normal habitat in marshy places, and 



