108 THE AMEKICAN MONTHLY. [May, 



fowls are removed in the manner already described. Our hen houses 

 and stables should be so constructed that they could be wiped over 

 with a solution of corrosive sublimate and leave no corners unwiped. 

 There should be no sharp corners where dust can accumulate and 

 which are difficult to reach. If, in spite of disinfection, the fowls all 

 die, the house should be thoroughly scoured with soap and water and 

 corrosive sublimate solution applied liberally and allowed to remain a 

 day or so, and again scoured and again disinfected several times before 

 other fowls are allowed to go in. If the yard is also infected, it should 

 be liberally doused with freshly slaked lime. It would be more effectual 

 to use corrosive sublimate even for disinfecting the yard, but that would 

 hardly be advisable. Freshly slaked lime is a good disinfectant, but it 

 must be applied to every part of the yard. The fences and ground in 

 every nook and corner should receive a thorough drenching. Not only 

 in chicken cholera, but in other infectious diseases the same means 

 should be used. 



The fact has been mentioned that lock-jaw does not occur any more 

 after surgical operations. If the wounds in animals are treated at once, 

 with corrosive sublimate or strong carbolic acid, there need be no fear 

 of lock-jaw. If a horse has run a nail in his foot, the wound should be 

 thoroughly washed out with a strong solution of corrosive sublimate 

 and stopped up with a plug of cotton soaked in corrosive sublimate 

 solution. The bacteria of lock-jaw are very wide-spread. They have 

 been found in garden earth, upon splinters of dirty wood, in old rags 

 and in the dust of rooms. 



Consider now the part played by bacteria in decomposition. As you 

 already know, the chief supply of food for the higher plants is furnished 

 by decomposed animal and vegetable matter. The higher plants can- 

 not make use of elaborate food — they can only assimilate such simple 

 bodies as the nitrates, etc. Complicated substances, such as animal 

 and vegetable matter, must be broken up before they can serve as food. 

 Now these complicated substances are just the things which form the 

 best food for bacteria, and bacteria decompose them so that the higher 

 plants can use them as food. It is, therefore, evident that bacteria are 

 necessary to the higher plants, and without them there would soon be 

 no life upon the earth, for animals are all ultimately dependent for food 

 upon plants. So bacteria prepare the food for the higher plants, the 

 higher plants supply food to animals, and animals and plants supply 

 food to the bacteria. For the sake of illustration, take the nitrogen 

 found in various albuminous substances. It amounts to 16 or 18 per 

 cent, in different cases, but as long as it is contained in the albumen it 

 is useless to the higher plants. The bacteria feed upon these albuminous 

 substances and liberate the nitrogen in the form of ammonia and nitric 

 acid, the only compounds of nitrogen which the higher plants are capa- 

 ble of using. The higher plants require nitrogen in the form of these 

 two compounds. Now here is a formula : Cj , H 33 No 3 , showing that 

 this substance called cerebrin contains nitrogen, but the nitrogen is 

 held so closely by the C, H and O that the higher plant could not use 

 it at all if it were not liberated. Nitrogen is used merely as an ex- 

 ample. What is said applies equally well to other substances be- 

 sides. Thus the mineral salts are also liberated from complicated 

 compounds by bacteria. 



