31 



time. It is slower with younger animals and such which are of 

 inferior development, as far as production of milk is concerned. 

 Good milking cows will generally on the third or fourth day 

 after calving, produce milk which can be boiled without shoM'ing 

 any coagulation of albuminous matter ; while young animals will 

 furnish, even on the sixth and seventh day, a milk which will 

 show partial coagulation on boiling, and in which colostrum cor- 

 puscles can be found with the aid of the microscope. 



Beside blood, albumen, casein, fat, and ashes, we find the fol- 

 lowing substances as normal constituents of colostrum : sugar, 

 globiiline, nucleine, urea, lecithine, and cholesterine. The pres- 

 ence of milk sugar has, as yet, not with certainty been demon- 

 strated. Eugling found the colostrum of twenty-two cows, of the 

 ages from three to thirteen years, composed as follows : 



Specific gravity 1.058 1.079 



Ashes. 1.180 2.310 



Fat 1.880 4.680 



Albuminates 11.180 20.210 



Casein 2.650 7.140 



Sugar 1.340 2.830 



Colostrum milk is especially characterized by comparatively 

 large (0.005 to 0.025 m.m. diameter) granulated corpuscles. Aside 

 of these, fragments in various degrees of dissolution are found, 

 which frequently consist only of conglomerates of fat globules. 

 Bunches of cells from the lactiferous ducts, generally larger than 

 the colostrum corpuscles, are also occasionally met with (see fig., 

 page 16). 



Poisoned Milk, 



Metallic poisons: Milk may occasionally contain poisonous 

 metallic substances. These are derived either from sour food 

 kept in metallic vessels and consumed by the cow, or may be im- 

 parted to souring milk which is kept in metallic vessels. (Taylor, 

 On Poisons, p. 412.) The acids which are formed during souring 

 dissolve the oxides of copper, lead and zinc easily. It is said that 

 zinc vessels are used in some localities tb delay the souring. 



Examinations fok Metallic Poisons : If the presence of 

 large, quantities of metallic substances is suspected, the examina- 

 tion may be carried on in the following manner : 



