(669 3 
far as they were not made in vegetative forms of bacteria, but in 
(anthrax) spores and that the dying off for the greater part was not 
brougbt about by heat, but by a chemical means of disinfection, 
viz. sublimate. . 
The said investigators think that they are able to give a mathe- 
matical formula for their curve. They assert namely that the 
same formula is applicable here, which holds good for the so-called 
monomolecular reactions, e.g. for the inversion of cane-sugar by acid: 
dx K 
ae (a—x). 
In this formula a represents the number of living anthrax spores 
that was originally present, w the number that has died off after 
a space of time ¢, and K a constant, expressing the velocity of 
reaction, i.e. the velocity of disinfection. In other words this formula 
means that during the entire process the number dying off at any 
moment, is in a constant ratio to the number of living individuals 
present at that moment. 
Therefore this A’ would yield a very suitable measure to judge 
about the action of a disinficiens under certain circumstances (of 
temperature, concentration, ete.). A much better measure than the one 
customary up till now, viz. the space of time necessary to destroy 
all germs. For it follows from what precedes that this space of time 
is to a high degree dependent on the number of germs which in the 
experiment has been started from. With this number the chance 
increases that there are some among them which ‘offer resistance 
extremely long. On the other hand & is not to that degree dependent 
on the number of germs used in the experiment *) and in order to 
calculate it, the experiment need not even be continued till all germs 
have died off, but two determinations of v at arbitrary points of 
time would suffice. 
For 
1 A—e 
MS - In —— +) 
t,—t, A—aQ, 
2 
These experiences of Mapsen and Nyman have been not only 
corroborated by an English investigator, Miss Harrinrr Crick *), for 
anthraxspores and sublimate, but she has stated a similar course of 
the curve also for the action of three disinfectants on vegetative 
1) Our experiences render it probable that a great number of germs per unit of 
volume somewhat retards the process of dying off. 
2) See the text-books about physical chemistry. 
3) Journal of Hygiene, 1908. 
