104 On Disinfectants. 



one-eiglitli of au ounce of concentrated carbolic acid, and then mixed 

 the two witli two ounces of milk. 



The addition of the concentrated carbolic acid prevented the coagu- 

 lation of the milk. 



The concentrated acid thus destroyed the active jiriuciple in rennet. 



4. Two ounces of the same milk were mixed with a quarter of an 

 ounce of rennet and a quarter of au ounce of a solution of carbolic acid 

 containing 1 part in 1000 of w^ater. 



The milk curdled in about 20 minutes. 



5. A solution containing L part of carbolic acid to 100 of water 

 similarly ap])lied did not prevent the action of rennet. 



6. To two ounces of milk a quarter of an ounce of rennet and a 

 quarter of an ounce of carbolic acid solution containing 1 part of acid 

 in 50 of water were added. The milk coagulated in about 20 minutes. 



7. Lastly, a quarter of an ounce of the same carbolic-acid solution 

 which was used in the preceding experiment (1 in 50), added to milk, 

 did not coagulate it. 



It thus apjiears that the active principle in rennet is only destroyed 

 or materially altered in character when it is brought into contact with 

 concentrated carbolic acid. 



Different organic substances most probably are variously affected 

 by carbolic acid, and it is quite possible that, whilst some are more 

 readily altered in their chemical composition than rennet, others may 

 resist its action with greater force. I found that solutions containing 

 1 part of carbolic acid in 50 of water in some experiments destroyed 

 the power of yeast to cause alcoholic fermentation. I am not, how- 

 ever, prepared to speak decisively on this j^oint until the experiments 

 have been repeated. 



The power of carbolic acid to arrest the decomposition of urine I 

 also find to be very great. 



The most convenient, and perhaps most efficient, i:)lan of using 

 carbolic acid in stables, cowhouses, &c., is to mix equal parts of water 

 and crude carbolic acid together, and to soak up the liquid com- 

 pletely by dry sawdust. Or two gallons of the mixture may be jjoured 

 at once over a sackful of sawdust. The sawdust so impregnated may 

 be handled with perfect safety, and when spread about in cattle-sheds 

 will charge the air with the volatile vapours of the most powerful 

 known antiseptic. 



The prepared sawdust should be kept in bags, and a little of it 

 spread every morning and afternoon. If it does no good otherwise, 

 it will certainly have the effect of keeping the shed free from the taint 

 of putrid urine and decomposing manures. 



Since the effects iDroduccd on animals by carbolic acid are very 

 remarkable, and the crude concentrated acid can be purchased at 5s. 

 per gallon, it is desirable to give it an extensive trial as a preventive 

 agent : in one way only can siich trials be injurious, if they encourage 

 farmers to become indifferent or careless about perfect isolation — our 

 only effectual safeguard. 



In conclusion, vigilance in excluding from farms, as far as practic- 

 able, butchers, veterinary inspectors, farm-servants coming from places 



