30 BULLETIN 224, U. S. DEPARTMENT OF AGRICULTURE. 



Touching the tips of such fingers very lightly against a petri plate containing agar 

 showed that their hands were far from clean, as is seen in Plate III, figure 4. The 

 growth on the plate itself was shown the girls and was a revelation to them. 



The lack of knowledge of the fundamentals of bacterial cleanliness is perfectly 

 apparent from the efforts of the management to conduct their business in a cleanly 

 fashion. The other appliances coming in contact with the liquid egg were just as ill 

 suited, bacteriologically speaking, to the work they had to do, yet every effort was 

 being made, so far as the knowledge of those in charge went, to throw away bad eggs 

 and to put out only a high-class product. 



COMPARISON OF COMMERCIAL PRODUCT WITH EXPERIMENTAL SAMPLES. 



Table 15 gives the laboratory findings on the liquid egg prepared under the con- 

 ditions just described. The minimum number of organisms obtained was 3,300,000 

 per gram; the maximum was 23,000,000. The number of gas producers in lactose bile 

 medium ran from 100,000 to at least 1,000,000. In many cases these results are too low, 

 because dilutions were not made in sufficient number to estimate higher counts. The 

 loosely bound nitrogen, calculated on the fresh material, was from 0.0020 to 0.0030 per 

 cent. 



All these samples were intended for human food. The tanners' egg which was being 

 made is shown in samples Nos. 327 and 484. There is a noteworthy leap upward in 

 both bacterial content and loosely bound nitrogen. 



This series of examinations in Table 15 does more than give the condition of the 

 final product in that it illustrates to a certain extent how the organisms increased as 

 the egg went from one container to another. The first of each of the paired exami- 

 nations represents egg which had been in contact with the hands of the breaker, the 

 knife blade, the little agateware pan, and the agateware bucket. The second sample 

 represents the same egg after it had been strained, thoroughly churned to mix white 

 and yolk, and allowed to pass through the rubber hose for storage in the large tank. 



Part II of Table 15 traces the liquid egg from the storage tank to the drying belt 

 and gives the final outcome after all the manipulations. During the drying process 

 the water content of the liquid egg is reduced to one-third or less of its original amount. 

 Likewise the number of organisms is reduced, though not in such marked propor- 

 tion. It must be remembered that bakers dissolve this dried egg in water; hence, 

 on the liquid basis it would have only about one-third as many organisms per gram 

 as are shown on the dry basis. The lowest bacterial count for the dried egg was 

 found to be 3,700,000, the highest 17,000,000, with an average of 9,200,000 per gram. 

 The loosely bound nitrogen in the dried product is considerably less than in the 

 liquid egg. Undoubtedly some of this form of nitrogen is driven off by the heat and 

 aeration in the process of drying; therefore this substance can not be taken as an 

 index of quality on the same basis as in the liquid product. 



In order to determine the effect of breaking the same eggs that were being used in 

 E house, in what might be termed an approximately bacterially clean fashion, the 

 experiments reported in Table 16 were made. The apparatus used for this purpose 

 was that described on page 27. It was cleaned by washing in running water, then 

 heated in a steam box for 20 minutes. The technique of breaking was as given on 

 page 23 for B house. The results are given as samples Nos. 485 and 486 in Table 16, 

 cracked and dirty eggs. Samples Nos. 489 and 503 were from the same lots of eggs, 

 but were broken by one of the women in the regular fashion. The difference in 

 bacterial content is astonishing (11,000,000 in the commercial product as compared 

 with less than 1,000 bacteria in the experimental samples in the case of dirty eggs), 

 but the loosely bound nitrogen is practically the same, indicating about the 

 same amount of aging in the shell. 



Sample No. 488 (clean eggs) was broken by the same operator who prepared the 

 other experimental samples, but in this case the usual equipment of the house was 

 used and the work was done as nearly as possible as the regular breakers did it. It 

 may be compared with sample No. 487, which was taken from the same lot of eggs 

 and was the work of an egg breaker employed in E house. It will be seen that like 

 equipment and methods produced like results, whether the operator was an egg breaker 

 or a bacteriologist. 



