A number of tabulations have been published showing the effects of the serum according to age groups, days of first injec tion, etc. The largest compilation is that of Flexner, dealing with about 1,300 cases in which the mortality among those treated in the first three days of illness was 18.1, the second three days 27.2 and after the seventh day 36.5%. The total mortality among these cases was 30.8%, as compared with 75 to 8o% among cor responding non-serum-treated cases. Netter's figures for the cor responding three periods are 7.14, I I•I and 23-5%; and Dopter's 8, 20, 14.4 and 24.1%. Flexner's figures are compiled from the reports of physicians at many places, while Netter's and Dopter's are based on personal experiences largely. Similarly, the influence of age on the results of the treatment is shown as follows : Accord ing to Flexner, under one year 50%, one to 20 years 75%, over 20 years 6o% recovered ; according to Netter, under one year one to 20 years 79% recovered ; and according to Dopter, under one year 53%, one to 20 years 78%, and over 20 years 76% recovered.
Certain important objective effects are produced when anti meningitis serum is administered. Perhaps the most immediately impressive is the modified character of the clinical course of the disease itself. Briefly stated, this relates to the essential disappear ance of the chronic cases slowly moving through weeks and months to a fatal issue, attended by hydrocephalus, extreme emaciation and other sequels. Either the cases fail to respond and terminate quickly, or in a few days the real infection is over and the patient convalescent. The growth and multiplication of the meningococcus within the cerebrospinal fluid are quickly arrested. Next, epi demic meningitis is a disease from which when recovery occurs spontaneously it tends to take place slowly, gradually, or by "lysis"; under the influence of the serum, sudden termination by "crisis" frequently takes place. Finally, the severe conse
quences, as of hydrocephalus, impairment of vision and mentality, paralysis and joint affections, are diminished. The one severe complication which has not been influenced is deafness, which occurs in a varying, usually small percentage of the cases, and usually very early in the disease.
Probably the meningococcus passes from the nasal mucous mem brane into the blood, with which it is carried to the meninges. Whether it ever passes along the direct lymphatic channels stretch ing from the nasal membrane to the meninges may be doubted. Instances are known in which meningococci were present in the blood some time before signs of meningitis appeared. The intra venous injection of the anti-meningitis serum has been successful in removing the microbe from the blood and of curing the general or blood infection. No meningitis followed. It is because of the occurrence of meningococci in the blood stream that early intra venous injection of the serum is recommended by certain author ities as a regular part of its intraspinal use in the treatment of epi demic meningitis. To be of value, the intravenous injection should be carried out very early in the diseaA, and it should not be sub stituted for the direct injection into the inflamed meninges. As a rule, a number of intraspinal serum injections on successive days is required to control the infection.
The successful employment of the anti-meningococcus serum has led to efforts being made to control other microbic varieties of meningitis in a similar manner, but thus far without notable success.