134 



DEPARTMENT OF THE NAVAT^ SERVICE 



Total solids were determined by the official method of the United States Depart- 

 ment of Apji'iculture on a fair sample of about 5 grams. 

 All the determinations were made in duplicate. 



Red Label samples obtained from factory. Blue Label Sample from St. Andrews 



There is probably some significance in the high ammonia and low urea figures 

 which I obtained from the sample sent from St. Andrews as contrasted with the high 

 urea and low ammonia content of the fish sent from Gorton-Pew. Probably some 

 change has occured. 



There was no odour of decomposition from the sample having the high ammonia 

 content, though it would be difficult to distinguish between the odours of decomposi- 

 tion and that of fish. If any extensive decomposition had occured, probably much 

 higher ammonia figures would have been obtained. 



APPENDIX B. 



(Extract from a letter by Dr. A. B. Macallum to the writer.) 



" There are two handicaps regarding dog-fish as food, from the point of view of its 

 urea content. One is that the urea changes to ammonium carbonate when the dogfish 

 stands at ordinary temperatures, and the amount thus transformed is in proportion 

 to the time during which the fish is allowed to stand at such temperature after it is 

 caught. The presence of ammonium) carbonate with the other odour of the fish makes 

 it exceedingly disagreable to the taste and smell, and, accordingly, dogfish as food must 

 be used soon after caught, or else it must be frozen and kept frozen in order to prevent 

 transformation of urea into ammonium carbonate. 



" The other handicap is an aesthetic one. One does not relish eating food in which 

 there is such a waste product as urea in abundance. 



" In canning fresh dogfish, of course, the water used in heating may withdraw a 

 considerable portion of the urea. That explains why in Dr. Baumann's exi)eriments 

 the quantity found was much less than the 2 per cent present in the muscle of the living 

 animal. 



" The observations regarding the dogfish are applicable to the skate and shark for 

 food." 



LITERATURE C.ITED. 



Addis, T. and C. K. Wataxabk. 



1916. The Rate of Urea Excretion. II. The Rate of Excretion of Administrated 

 Urea in Young Healthy Adults on a Constant Diet. Journ. Biol. Chem. 



Beax, T. 

 1903 



Vol. 27, p. 249. 



H. 



Catalogue of the Eishes of New York 



Bell, R. 



1859. On the Natural History of the Gulf of St. Lawrence 

 and Geologist. Vol. IV. 



N.Y. State Museum Bull. 00. 



Canadian Naturalist 



