184 REVIEW — TROPICAL MEDICINE, ETC. 



Small-pox become an efficient help in diagnosis. It is not at all uncommon in small-pox hospitals to 

 —coniiiiual see siuall-pox and vaccinia run parallel courses simultaneously in the same patient. 



Finally, he tabulates sources of error in diagnosis as follows : — 



1. In.iccurate history, e.g. former alleged attacks of small-pox. Too short or too long a period intervening 

 since exposure. 



2. Belying too much on the j)re3ence of vaccination scars, even when performed a few months previously. 

 Their presence does not justify the exclusion of small-pox. 



3. The formation of septa in the vesicle, estimated by pricking with a needle along the periphery. In 

 small-pox the vesicles are said to stand, but in chicken-pox to collapse, being unilocular in the latter. This 

 is a most unsatisfactory criterion and quite unreliable. 



4. Presence or absence of umbilication — this, too, is no sure guide. 



5. Being satisfied with the existence of a cause sufficient to explain the existing clinical complex without 

 making sure that the cause thus presumably ascertained is the actual and effective agent — the causa causans. 



In order to avoid this, it may become necessary in cases of difficulty to examine the various systems 

 (digestive, cutaneous, vascular, etc.), in fuller detail and methodically. 



In conclusion, although the diagnosis of small-pox is at times easy, there are occasions upon which it is 

 most difficult, and no one sign is to be absolutely relied upon. Cases such as acne with granular kidney, 

 chlorosis with backache, septic rashes from causes unascertained, syphilis in a rheumatic subject, a case of 

 cerebral tumour, taking KI. or KBr. with vomiting — -all these may be most misleading. 



In cases where small-pox is present, however, it is often found th.it though the patient admits having 

 had previous attacks of the same kind, yet the present is the first occasion on which he has for this cause 

 abstained from work, laid up at home, or " had a doctor at home." 



The whole article is well worthy of careful study. 



Xylol has been recommended in the treatment of small-pox. Abbott' records a case 

 treated successfully with it in India. Tlie dose varies from 10 to 60 drops in milk, the 

 larger quantities being given in three doses daily. 



Nesfield,'^ influenced by the resemblance of small-pox to syphilis, and especially to the 

 acute secondary form of the latter, tried treating the former condition by large doses of 

 mercury with chalk. In all he treated eight cases — seven adults and a boy. To the former 

 he gave 10 grains of mercury with chalk three times a day for six days, then twice a day for 

 four days, and once a day for four days more — 14 days in all. Although the number of cases 

 treated does not justify any definite expression of opinion, he concludes : — 



1. Ten grains of mercury with chalk three times a day by the mouth, continued for six days, produces no 

 symptoms of poisoning in small-pox. 



2. The drug appears to have a marked action in modifying and reducing the severity of the disease. 



Snake Bite. Most of the papers on this subject are of a highly technical character 

 and need not be considered here. Eight species of poisonous snake are now known in the 

 Sudan, and these will be fully described and illustrated in a forthcoming work by Professor 

 Werner, of Vienna. This authority has, however, very kindly furnished a short but useful 

 account of these and other Sudan snakes, based partly on material collected by Dr. Wenyon 

 (Third Keport). Snake bite is not at all common in the Sudan. I have made many enquiries 

 on this point, and have been invariably informed that cases are not often seen. Naja tiigro- 

 collis, the spitting cobra of the Sobat, is one of the most dreaded by the natives, and, thanks 

 to the kind help of Dr. McLaughlin, of the American Mission of the Sobat, a sample of the 

 venom, or rather of the ejected fluid, was obtained and sent to Professor Sir T. E. Fraser, of 

 Edinburgh. Unfortunately, the quantity was so small that, though it was found to be 

 active, Professor Fraser was unable to carry out any extended observations upon it. One 

 hopes to secure a larger quantity later on, and applications for samples has been made in 

 different quarters. It is acid and the antidote is an alkaline wash. 



Eogers^ has a paper on the treatment of snake bites. He divides poisonous snakes into 

 two classes as regards their physiological actions. 1. Colubrine including certain sea snakes, 

 the cobra and the krait of India : 2. Viperine including the African pufl'-adder, the Indian 

 daboya, etc. (true vipers), and other rattlesnakes, etc. (pit vipers). The venom of the first 

 class kills by paralysing the respiratory centre, that of the second by pai'alysing the vaso- 

 motor centre. 



» Abbott, S. H. L. (May, 1906), " Xylol in SmaU-pox." Indian Medical Gazette, Vol. XLI. 



' Nesfield, V. B. (AprU 25th, 1908), " On the Treatment of Small-pox by large Doses of Mercury and Chal 

 tc<V, Vol. I. 



' Rogers, L. (September 17th, 1904), " The Treatment of Snake Bites." British Medical Journal, Vol. II. 



