268 Report S.A.A. Advancement of Science. 



HEART-WATER. 



In my Annual Report for 1896, observations were made which 

 at a later date were communicated to the Royal Society (Vol. 65) 

 showing that the germs of Red-water or Texas Fever may remain 

 latent in the blood of cattle for long periods of time after their 

 recovery from an attack of the malady, and that cattle born on Red- 

 water veld, although they may not have been affected by this malady, 

 yet can, and do carry infection, in a latent form, in their blood. 



During my investigations into Heart-water I began to have 

 suspicions that something of the same nature was concerned in regard 

 to the latter malady. 



The following experiments shew in how far these suspicions 

 were verified : — 



Experiment i. — To prove that the contagium of Heart-water 

 may be communicated to a susceptible animal in a non-virulent form 

 and passed in succession through several others, eventually being 

 raised to full virulence in the passage. 



I obtained a number of clean goats by train from a clean area, 

 and enclosed them in a courtyard, which, in turn, was bounded by 

 stone walls. 



Along one side of this yard galvanised iron enclosures were 

 erected, into which the animals were placed while under experiment. 

 The most rigorous care was exercised in regard to cleanliness of the 

 place, each shed being at frequent intervals thoroughly cleaned and 

 disinfected. 



While I have found that Horse-sickness blood can be pre- 

 served by the addition of an equal volume of glycerine and water 

 containing i per 1,000 of Phenol, so that it retains its virulence for 

 at least three years, the blood of goats dying of Heart-water when 

 so treated loses its virulence in a few days. Such preserved 

 blood does, however, almost always set up a slight oscillation of the 

 temperature in animals inoculated with it. 



Goat No. 252 was inoculated with 10 c.c. of glycerinated blood 

 taken from an animal which had died of Heart-water. The injection 

 of this material was made subcutaneously on September 5th, 1901. 



No febrile change was observed until the 21st September. On 

 this day the temperature rose to 107F. in the middle of the day, 

 but regained the normal on the following day. 



Goat No. 258 was now inoculated with 100 c.c. of the blood of 

 No. 252. 



Some irregularity of temperature was produced, but no very 

 definite reaction, and on the 9th October (being the fourteenth day 

 after inoculation) it was bled, and Goat 265 was inoculated sub- 

 cutaneously with 100 c.c. of its blood, and with 25 c.c. injected into 

 the jugular vein. 



On the following day there was a sudden elevation of tem- 

 perature to io6'4, and on the fifth day the animal died of character- 

 istic Heart-water. 



