REVIEW — TROPICAL MEDICINE, ETC. 217 



potency, although, if kept at the approximate temperature of an ice-bos, viz., 10° C, it Vaccination 



loses its activity as a vaccine to a certain extent. —continued 



Nield Cook's method, employed in Calcutta, consists in making enough glycerinated 

 lymph to last till the next cold weather, the vaccine being poured into test-tubes nearly 

 up to their rim. These are sealed by sterile corks which are pushed in so as to squeeze 

 out a little vaccine, and thoroughly waxed over. The test-tubes are then placed in tin 

 cases, which are sealed up and put away in a tin box, and this is stored in an ice company's 

 cold storage at a temperature of 5'' C. Nield Cook considers that rabbits are valuable 

 additions to a lymph depot. He makes use of the rabbit : — 



(1) To estimate the strength of the vaccine employed by inoculating the shaved backs 

 of rabbits with 1 c.c. of varying dilutions of vaccine. If the crop of vaccine is of excellent 

 quality the eruption produced by a dilution of 1 in 500 is still confluent. 



(2) To renovate the vaccine. If a stock of vaccine be rapidly passed through a series 

 of calves, it soon begins to deteriorate^especially under unfavourable climatic conditions. 



Pulp may be taken from a rabbit on the fourth day, diluted with glycerin, and this 

 glycerinated rabbit vaccine used for the vaccination of calves. 



(3) The rabbit may be used to observe whether the vaccine is acting efficiently. 



Vaccine in India is preserved either in lanoline, glycerin or chloroform. Lanolated 

 vaccine has the disadvantage that micro-organisms may grow in it after it is made, 

 although claims are made for it that it retains its potency under unfavourable climatic 

 conditions. Vaccine preserved in chloroform resists the ingress of bacterial impurities, 

 and, owing to the rapid bactericidal action of chloroform, this method of preservation is 

 useful if vaccine is required in a hurry, as it takes some time for the germicidal action of 

 glycerin to develop. 



Hans Ziemann^ has a very practical article in the Berliner Klin. Wochenschrift, 1908, 

 No. 3, on " Protective Inoculation against Small-pox in the Colonies." This observer 

 advises that only such vaccines should be employed for vaccination as are subject to 

 Government control, and that an institute for the preparation of lymph should be 

 established in every colony. Care should be taken to select healthy young calves, three to 

 six months old. It is advisable to vaccinate a human subject with lymph freshly imported 

 from Europe, and then to use this humanised vaccine with which to inoculate the calf. In 

 localities where no calves are available, efficacious vaccine, similar to calf vaccine, may be 

 obtained from buffaloes, gazelles, camels, dogs, horses, donkeys, pigs, monkeys, guinea pigs 

 and rabbits. 



Ziemann further recommends that the technique of vaccination carried out should be 

 the same as in Europe, and should be performed in the cool season or during the coolest 

 hours of the day. He holds that vaccination is successful if one well-developed pustule 

 results. 



Native adults should have six incisions on the left upper arm, while eight on those of 

 children will suffice. If sufficient calf lymph be not available, arm-to-arm vaccination may 

 be performed as long as no doubts exist as to the liability of infection through relapsing 

 fever or sleeping sickness. The vaccine should only be taken from healthy children up to 

 about eight years of age. Ziemann strongly recommends an important practical point, viz., 

 that every colony should have travelling doctors appointed to undertake the systematic 

 vaccination of the population, especially on caravan routes, and that native assistants 

 should be instructed in the technique of vaccination. As regards the Sudan, the benefits 

 conferred by vaccination are much appreciated by the natives, who in the past have 

 suffered severely from the ravages of small-pox, and are only too willing to submit to such 

 an efficient preventive measure. At present all vaccine lymph is imported into the Sudan, 

 stored on ice and issued as required. It appears to be of a satisfactory quality, but 

 doubtless it would be better to have a vaccine institute established in tlie country, 

 especially for the supply of lymph to the more distant provinces. 



Veterinary Diseases. The subject of veterinary diseases is one of very great 

 economic importance in the Tropics. Some of the diseases affecting animals have 

 already been considered, and, as regards these, there is no necessity to reiterate. 



' Ziemauu, H. (August lath, 1906), " Small-po.x iu the Tropics." Journal of Tropical Medicine and Hygiene, 

 Vol. XI., No. 10, p. 159. 



