tgb THE POPULAR SCIENCE MONTHLY. 



instructive to some who may chance to be at all dubious as to the 

 destructive effects of boiling water upon lower organisms. 



Probably, however, some of my readers may already be possessed 

 by the notion that the disastrous effects just referred to are conse- 

 quences following rather from the fact of the high organization of 

 man's tissues than from any intrinsic incompatibility of nature be- 

 tween living matter and boiling water. The thought is natural 

 enough and not unjustifiable. On the other hand, it will not do to 

 attach much importance to it. Let us for a moment consider the 

 effects produced upon an ordinary hen's egg by a brief immersion in 

 boiling water. Here we have the " white," composed of albumen, 

 similar to that which enters so largely into the composition of living 

 tissues, turned from a clear fluid into an opaque solid ; and we have 

 the " yelk," made up of a dense aggregation of the simplest living 

 units, also more or less solidified. In spite of the investing calcareous 

 shell, these very obvious and destructive effects can be produced upon 

 this large egg or germ by an exposure for three or four minutes to 

 the influence of boiling water. Yet the living matter in this case 

 is so simple that it possesses next to no organization — it is so little 

 vitalized that it can only be considered to be half alive. 



The conclusion would seem, therefore, to force itself upon us that 

 there is something intrinsically deleterious in the action of boiling 

 water upon living matter — whether this living matter be of high or 

 of low organization. 



This subject is one of great importance in many respects, so that 

 it may repay us to look into the evidence bearing upon it with some 

 degree of care. It is of great practical importance, for instance, in 

 reference to the process of disinfection by heat, where we have to do 

 with articles of furniture or wearing apparel used by a person suffer- 

 ing 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, suflSces 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. Again, from 

 a purely scientific point of view, the question is of equal cogency 

 because of its bearing upon one of the most momentous problems in 

 biological science — namely, that of the Origin of Life. It is on this 

 latter account, more especially, that I now take up the inquiry as to 

 the grade or degree of heat which proves destructive to different 

 kinds of living matter. 



A preliminary word of explanation, therefore, must be given con- 

 cerning the bearings of this question upon the Origin of Life problem. 



It is at present very generally admitted, upon the strength of 

 well-known experiments, that living matter will appear and grow 

 rapidly in hermetically-sealed flasks containing certain fluids, after the 



