228 CURRENT NOTES. 



Apparently the addition of one grain of copper sulphate to one gallon of 

 water was, under certain conditions, sufficient to destroy the vitality of the 

 typhoid bacillus. This subject has received serious practical attention by the 

 United States Department of Agriculture, and an interesting report was 

 issued in 1906 by Mr. Karl F. Kellerman and Mr. T. D. Beckwith on behalf 

 of ihat Department. We have ourselves found that sulphate of copper in a 

 very small proportion (roughly, an avoirdupois ounce in about 120 gallons of 

 water — ?'. e.j under a grain to the pint) will prohibit the growth of algie in 

 an ordinary garden rain-water tank, and possibly this method may be worth 

 a trial." 



Tsetses attracted by moving objects. 



In a letter to Mr. E. E. Austen, Dr. A. E. Neale gives the following notes 

 on a peculiar habit which he has observed in two species of Glossina : — 

 '^ During my last tour, in Northern Nigeria, I spent some days unsuccess- 

 fully searching for tsetse-flies in a certain area in which I felt sure they 

 must exist. On these occasions I was always on foot and moving slowly and 

 carefully. A little later, I had occasion to go through this belt on a bicycle. 

 The native path was fairly good and I was riding fast, when soon I became 

 aware that I was being besieged by tsetses. The}^ settled all over me, in- 

 cluding my hands and face, and being unable to beat them off with one 

 hand, I had to dismount. Ha\ing no net with me at the time, I was able to 

 catch only a few specimens with my handkerchief, these proving to be all 

 palpalis, with the exception of one tacliinoides. I w^as now quite free from 

 flies and mounted the bicycle again, but no sooner had my pace become 

 fairly fast, tlinn I was again besieged by tsetses, and was compelled to beat 

 them off as before. I repeated this several times, and found that whilst 

 walking I was not attacked, but as soon as I Nvas travelling fast I was 

 immediately surrounded. This belt was about 3 miles wide. Horses in this 

 district all went down with tsetse disease. 



" This portion of the country abounded in game, chiefly hartebeeste, roan, 

 kob, oribi, duiker, harnessed antelope, reedbuck, and occasional waterbuck. 



" It appeared to me that these flies are attracted by fast moving animals, 

 which would account for my being specially attacked whilst riding fast on 

 the bicycle. I repeated my experiments later, by walking quietly with the 

 bicycle right into the belt, without encountering a single tsetse ; but when 

 I mounted and began riding fast^ I was again besieged, and the faster I rode 

 the more furiously I was attacked. 



'^ I have noticed a somewhat similar experience on the river. When 

 moving very slowly in a canoe, as when fishing, I do not ever remember 

 having been troubled by tsetses. But when being poled fast, with the stream 

 in one's favour, or when in a small steamer, I have had Glossina settling on 

 board. 



