There are a large number of microbes capable of hydrolysing the 

 molecule of free sulphur in the presence of albumins. As the sulphur- 

 etted hydrogen thus formed can readily be detected by means of lead 

 acetate paper, the occurrence of this hydrolysis can conveniently be 

 followed up. On the other hand, it is naturally also easy to deter- 

 mine with the aid of this method, whether an antiseptic agent added 

 impairs the formation of sulphuretted hydrogen, or (as the case may 

 be) arrests it altogether. As not everybody has pure cultures of 

 bacteria at .disposal, it is interesting to know that according to experi- 

 ments 1 ) made at our Institute by Hermann Briining, the so- 

 called normal milk bacteria, as present in all milk of marketable quality, 

 bring about this formation of sulphuretted hydrogen with great certainty, 

 if finely powdered sulphur is added to the milk and the latter 

 placed for 24 hours in the incubator. Of pure cultures of bacteria 

 which can be used for the same purpose, Briining has found, for 

 example, Bacterium colt very useful. At the suggestion of Prof. Kobert, 

 he has made comparative experiments on the antiseptic action of 

 numerous essential oils and their constituents 2 ), according to this method. 

 As milk, although obtained from the same source, and of the same 

 age, is not always exactly uniform with regard to its content of bac- 

 teria, it appeared desirable to take up the experiments once more and 

 extend them in some directions, before the publication or abstraction 

 of B runing's results in these Reports. These experiments I have 

 carried out, and embodied them also in the table lower down. 



The milk- experiments were made in the following manner. Quan- 

 tities of 10 cc. each of raw cow's milk were placed in test tubes and 

 mixed with finely powdered sulphur, as much as would lie on the 

 point of a knife, in the form of sulphur praecipitatum. Next there 

 were added to the milk by means of the same pipette in increasing 

 quantities, namely 1, 2, 4, 6, 8, 12, 16, 20, 24, 32 drops and finally 

 1 cc, the essential oils (or their constituents) of which the action 

 was to be tested. It goes without saying that one cc. does not with 

 every oil contain the same number of drops. In some test tubes only 



*) Briining, Uber das Verhalten des Schwefels zu Milch (und Milchpraparaten) 

 sowie zur Schleimhaut des Magendarmkanales [On the behaviour of sulphur towards 

 milk (and milk preparations) and also towards the mucous membrane of the gastro- 

 intestinal canal], (Zeitschr. f. exp. Path. u. Therap.). 



2 ) Briining, Atherische Ole und Bakterienwirkung in roher Kuhmilch [Essential 

 oils and bacterial action in raw cow's milk] (Centralbl. f. inn. Mediz. 27 [1906], 

 No. 14). 



