PART I.] Action of Heat on the Virulence of Snake Poison. 175 



that of the latter 47 per cent., — thus proving that heat applied to this extent, at all 

 events, had not diminished the toxic influence of the substance experimented with. 



It is of very great importance to know definitely what is the effect of heat upon 

 such organic substances as are known to be capable of manifesting virulent properties 

 when introduced into the animal economy. This agent appears to us to offer a more 

 trustworthy means than any other for ascertaining whether or not the active principle 

 of these poisons is transmitted by infection with certain vitalised particles. In ultimate 

 relation to this subject, as recently pointed out by Dr. Bastian in his remarkably sug- 

 gestive essay on " Heat and Living Matter," are many important questions with reference 

 to the process of disinfection, " where we have to do with articles of furniture or wearing 

 apparel used by a person suffering from a contagious disease. Because in such a case, 

 what we ought undoubtedly to know is whether the temperature of boiling water or 

 even some lower temperature suffices to kill any living particles which may act as 

 so-called ' germs of disease.' This is a subject upon which there should be no room 

 for doubt."* 



We had hoped to have been able to have submitted on this occasion a series of 

 experiments regarding the effect of heat upon the infecting principle in two un- 

 doubtedly contagious diseases — small-pox and vaccinia. The observations which we 

 have commenced are not yet in a sufficiently advanced state to be published. We 

 have, however, been able to satisfy ourselves to a certain extent with regard to the 

 action of heat on another well-known animal secretion possessing most virulent pro- 

 perties, namely. Snake-poison. 



Last April we were asked by Dr. Ewart, the President of the Snake Commission, 

 to undertake some microscopic examinations of fresh virus of the Cobra and of an 

 Australian snake.f In order to conduct these examinations. Dr. Vincent Kichards 

 caused several snakes to eject their poison into a watch-glass in our presence. The 

 poisons from the two species of snakes were transferred into separate test tubes, having 

 been previously diluted with about five parts of distilled water. Each sample was 

 subsequently divided into two parts : One test tube, containing the simple aqueous 

 solution of the virus, was set aside ; the other test tube, containing the remaining 

 half, was placed in a vessel of hot water and thoroughly boiled for ten minutes. J This 

 proceeding enabled us to carry out two series of observations — (I) with unboiled and 

 boiled aqueous solutions of virus obtained from the Cobra ; and (II) with unboiled 

 and boiled solutions of the virus from the Australian snake : — 



* Contemporary Review, September 1874, p. 517. 



f These microscopic examinations need not be specially referred to here, as the results are embotlied in 

 the report which has just been issued by that Commission. Suffice it to say, that we could distinguish no 

 cells or organisms of any kind in the poison which were not equally present in the inert secretion obtained 

 from the fauces of the snake. On several occasions, however, we observed that acicular featheiy crystals 

 had formed on some of the slides, and that numerous fusiform crystals were precipitated in the course of two 

 days from the aqueous solution of the virus. All these will be found figured in the report referred to. 



% On being placed in the warm water, the solution of virus in the test tube soon became turbid, 

 and a flocculent precipitate was seen to form long before it had been heated to boiling point. 



