June 20, 19 18] 



NATURE 



315 



sibly only a few can ever succeed in biting a human 

 boiiig at' all. Then only a proportion ot these will 

 generally have bitten an infected human being; and, 

 again, only a smaller proportion will have bitten an 

 infected person whose blood contains sexual parasites 

 suitable for transmission into a mosquito. Hence the 

 chances usually are that only a very small proportion 

 of all the An.ophelines in a place will ever become 

 infected at all. But how many of these will infect 

 healthy persons? A mosquito must live for about ten 

 days at least before the parasites can mature in her 

 bodv and enter her salivary glands, and of the small 

 proportion of mosquitoes which may live long enough 

 for this a still smaller proportion are likely to succeed 

 in biting and infecting healthy persons afterwards. 

 Men and mosquitoes may vary in individual resistance 

 to parasites. Both will be infective to each other only 

 at certain times. The general equations for' diseases 

 common to two species of hosts contain fifteen inde- 

 pendent constants, or, rather, parameters — namely, the 

 birth-rate, death-rate, immigration, emigration, im- 

 munity, infectivity, and recovery ratios for each 

 species of host, and the contact ratio common to both ; 

 and the total proportion of infected individuals of 

 either species must depend on ^all of these combined 

 in certain mathematical functions." A special appeal 

 was made to the members of local societies to make 

 a study of the bionomics and distribution of mos- 



'i quitoes in Britain. 



A lecture was given by Mr. Reginald Smith, of the 

 British Museum, on the "Geology of Flint Imple- 

 ments." In the course of many interesting remarks, 

 the Mousterian cave-finds from St. Brelade, Jersey, 

 were illustrated, and compared with certain surface- 

 finds in England. The hope was expressed that 

 further research in England, which had the advantage 

 of the boulder-clay, might decide man's relation to 

 the glacial period by associating definite types of flint- 

 working with deposits both before and after the most 

 intense glaciation of the country. Much information 

 had been lost to science by inattention to the labelling 

 of specimen*; as to their place of origin and the posi- 

 tion in which found. 



Other papers were: "Meteorological Instruments 

 and How to Read Them," by Mr. R. Corless, of the 

 Meteorological Office, and by Lieut. R. W. Ascroft, of 

 the Food Production Department, on "Allotment 

 Pests." Among the afternoon excursions may be men- 

 tioned visits to the New Transport Co.'s works at 

 Battersea, where heavy goods are sorted by machinery, 

 on the principle of a central goods clearrng-house ; to 

 the church of St. Bartholomew the Great; to the 

 classic Charlton Pits, under the guidance of the 

 veteran geologist, Mr. W. Whitaker; to Kew, under 

 that of Lieut.-Col. Sir David Prain and Prof. G. S. 

 Boulgcr; and to the diving and mine-rescue apparatus 

 works of Siebe, Gorman and Co., under the direction 



j of Dr. J. S. Haldane. The congress was well 



I attended, and apparently justified the council in decid- 



f ing to hold it this year as usual. 



THE TREATMENT OF MALARIA.'^ 



THE treatment of malaria has engaged the atten- 

 tion of the medical department of the War Office 

 since the outbreak of the war. So soon as cases of 

 this disease began to return to England malaria hos- 

 pitals were opened, and in certain large hospitals 

 rial wards were set apart so that all patients could 

 roncentrated and treated by physicians with special 

 Knowledge of malaria. This branch of the medical 

 work was placed under the supervision of Col. Sir 



1 Society of Tropic-il Medicin»^. (i) .\n Interim Report on the Treatment 

 of Malaria. (2) Report on a " Discussion on the Treatment of Malaria." 

 Both by Sir Ronald Ross. 



NO. 2538, VOL. lOl] 



Ronald Ross, K.C.B., F.R.S., consultant in malaria. 

 War Office, and an interim report now published by 

 this officer gives the results of treatrnent of a number 

 of cases in four of the hospitals linder his control 

 up to the date of publication. 



Before commencing treatments, 193 patients who 

 had previously taken quinine, but who had recently 

 discontinued the drug, were observed without further 

 medication with the view of determining approximately 

 the liability to relapse without further treatment. Of 

 these 193 patients, 88 had relapses within twenty-seven 

 days. Owing to illness (unfortunately not specified), 

 76 had to be given quinine without continuing the 

 control. After a month, only 15 per cent, were free 

 from relapse, and were considered well enough to be 

 discharged ; 85 per cent, were still showing symptoms 

 of the disease. 



Two thousand four hundred and sixty cases of 

 malaria were treated under one or other of the fol- 

 lowing methods : — 



(a) Anti-relapse Quinine Prophylaxis. — Quinine sul- 

 phate in small doses by different methods up to 

 60 grains weekly was given to 1040 cases. A dose of 

 10 grains daily was found to be more effective than 

 one of 5 grains, and was more suitable than one of 

 15 grains, because, as well as being equally effective, 

 it was better tolerated. Under these treatments re- 

 lapses were reduced to 10 per cent., and even in 

 relapses not so reduced the severity of the paroxysms 

 was diminished. 



(b) Short Sterilising Treatments. — Large doses of 

 quinine sulphate, hydrochloride, or bi-hydrochloride 

 were given dailj' for seven days, or on consecutive 

 days up to ten days, to 334 cases. A high percentage 

 of these cases relapsed. 



(c) Long Sterilising Treatments. — Large doses of 

 the same salts of quinine as in treatments (b) were 

 given dail>' over long periods, continually, or on con- 

 secutive days, or at intervals of several days. Some 

 of these treatments appear to have given the best 

 results, especially the three treatments (c) 15, 16, and 

 17. Two of these were combined in the later stages 

 with iron and arsenic. It may be noted that, in the 

 experience of some observers, much intolerance is 

 shown during the large dosage as here used, with- 

 out more appreciable diminution of the number of 

 relapses than results from less heroic lines of treat- 

 ment. 



{d) Mixed Treatments, including the administra- 

 tion of drugs other than quinine in the combinations 

 generally used, were given in different doses for vary- 

 ing periods. The drugs used were tartar emetic, acid 

 arsenoids, sodium quinine sulphonate, ethyl quitenine 

 hydrochloride, and collosol quinine. Only a few cases 

 were treated with ^ach drug, as nearly all these 

 relapsed. 



Sir Ronald Ross points out that he has not noticed 

 any marked superiority in the oral, intramuscular, or 

 intravenous methods of administering quinine. He 

 advises that a much larger number of cases should 

 be controlled before the efficacy of any particular drug 

 over others can be determined. Obviously it is neces- 

 sary to observe cases carefully for a much longer 

 period than twenty-seven days after they leave hos- 

 pital before it is possible to decide what is the actual 

 liability to relapse. 



.\ generous diet is recommended during treatment, 

 with a little stimulant in the form of beer or wine. 

 Opinion seems divided as to whether patients should 

 be kept in bed or not during treatment. 



.\ second paper expressing the opinions of medical 

 officers in the Salonika area as to the value of pro- 

 phylactic quinine and on the treatment of malaria 

 under different conditions of service was afterwards 

 read by Sir Ronald Ross before the Society of Tropical 



