9 



an age of three weeks, wheat was gradually substituted for the chick food. 

 Nearly all the food from this time on was fed from hoppers, or otherwise 

 kept constantly in front of them. 



The April chickens were fed more in the litter because they could not 

 get out of doors as well owing to bad weather. 



Why Certain Materials Were Used in the Incubators. 



Early in the winter we were looking for some method by which to 

 increase the carbon dioxide in incubators. The idea was suggested to us 

 that by the use of a species of bacteria which produces large quantities 

 of gas we might be able to get the carbon dioxide in sufficient quantities. 

 We obtained from the Bacteriological Laboratory a culture which would 

 grow readily in milk. This culture was said to be one of the most gassy 

 known. In order to produce the carbon dioxide this culture was mixed 

 with milk and the milk renewed every four days during the period of 

 incubation. We next considered whether sweet milk would be better than 

 sour milk, or whether whole milk would be superior to skim-milk. 



We tried operating machines with whole milk, skim-milk, and butter- 

 milk. We have some machines that have been operated where buttermilk 

 was used with the carbon dioxide starter and where buttermilk only has 

 been used. 



After making several post-mortem examinations of incubator chick- 

 ens, and noting their peculiar conditions, we were of the opinion that this 

 might be a bacterial disease. Not then having results of all the work 

 done in the Bacteriological Laboratory, we thought it would be a wise 

 precaution to disinfect the incubators. We had two common disinfect- 

 ants on hand — mercuric chloride and zenoleum. The incubators during 

 the second hatch were washed with a 10 per cent, solution of zenoleum. 

 By this we mean that the inside of the machine, including the tray, the 

 thermometer, the top, the bottom and the sides, were thoroughly scrubbed 

 with this solution. While the machine was still wet, the eggs were placed 

 on the trays and started. Practically the same method was used with the 

 mercuric chloride, with the exception that we endeavored to use it much 

 more freely on the woodwork than upon the metal parts of the machine. 

 No other disinfectants have been tried. Possibly other carbolic or creosote 

 compounds would give equally as good or even better results. We have 

 not had the machines, nor the time, this year to branch out from this one 

 line. Theoretically, several other compounds should be as good. One 

 of our co-operative experimenters reports excellent results on the use of 

 Jeyes' Fluid, and a friend says he got good results from creolin. These 

 trials are the outcome of a knowledge of our unpublished results. When 

 visiting poultry plants a few years ago, the writer, along with L. H. 

 Baldwin, of Toronto, and F. C. Elford, of Macdonald College, were led 

 to believe from observation that a strong odor of lamp fumes in an incu- 

 bator room was likely to produce a chick low in vitality. A test or two 

 was made at this College with dry machines operated in small rooms, and 



2 BULL, 163 



