EFFECTS OF SNAKE \l-:N(nrS ON DOAIESTIC ANIMALS. ^5,^ 



woidd uncloubtedly simplify ]»()l\valent antivenomous scrum pro- 

 duction. 



Animals whose serum has Ijeen tested and found up to stan- 

 dard, are bled ten days after the last injection. The quantity of 

 blood taken de])ends on the si.ze and condition of the animal, but 

 averages 7 litres. The animal can be bled twice later at hvc-day 

 intervals, and 4 to 5 litres taken at each bleeding. Ten days after 

 the last bleeding, injection of venom can be recommenced, and the 

 administration can now be more rapidly pushed than on the 

 former occasion. 



The serum collected from the l)lood taken is distributed 

 under ase])tic conditions into ampulla? of 25 c.c. capacity, which 

 are hermetically sealed. These ampullar are heated in a serum 

 inspissator for one hour at a temperature of 58° C. on three suc- 

 cessive days, in order to ensure absolute sterility. The serum 

 thus prepared will retain its antitoxic ]iro])erties unimpaired for 

 about two years if kept from sunlight and stored in a cool place. 



After some time the serum becomes changed owing to the 

 <leposit of albumen, which settles to the bottom on standing, in 

 the form of flakes. This deposit is partly redissolved on shaking, 

 and its presence is not a sign of deterioration of the serum. 



Each ampulla contains one dose of senun. When re- 

 quired for use, part of one or two doses is injected as soon as 

 possible, with a hypodermic syringe, into the subcutaneous tissues 

 of the flank, and the remainder into the tissues aroitnd the bite. 

 If delay ha> occurred and absor])tion has taken place, it is best 

 to inject all the serum into the flank, or in cases where symptoms 

 of serious collapse are ])resent. it is preferable to inject the serum 

 directly into one of the large veins, the most suitable being those 

 of the inner side of the forearm just below the elbow. 



If this method is carried out, it is necessary to avoid injection 

 of sera containing flocculi, either by careful decantation of the 

 clear su])ernatant fluid or filtration through filter paj^er. 



Antivenomous serum can be desiccated, and in this form 

 IS much more portable, and it has the additional advantage of 

 retaining its antitoxic properties indefinitely if kept hermetically 

 sealed. Rx])eriments carried out with desiccated serum j^repared 

 against puff-adder venom at i*ietermaritzburg J.aboratory have 

 shown that it is not only e(|ual in activity in fresh solution to 

 ]mff-adder antivenomous serum, but also, if used locally in the 

 dried form after free incisions into the area bitten, its action is 

 much more rapid in neutralising the injected venom than per- 

 manganate of potash. 



Serum on desiccation becomes reduced to about one-eleventh 

 of its original volume, and thus 2 grammes of the powder are 

 •equal to about a dose of the serum. 



When required for use the i)Owder can be added to 20 c.c. of 

 water which has been boiled and cooled, in which it fairly readily 

 dissolves, and injected in the same manner as antivenomous 

 serum. 



