[9] The chemicals employed have no effect upon iron. They will, however, actively corrode zinc, tin, or solder; hence a soldered pail must be watched for leaks and is far inferior to a seamless pail, stamped from a single sheet of iron. A tinned pail is preferred to a galvanized one, but a plain iron seamless pail or an iron kettle should be obtained if possible.
[10] Best done by previously determining by measurement the depth of 5 gallons of water in the kettle. Set the kettle exactly level and mark the depth on a stick held vertically on the center of the bottom.
ANIMAL PARASITES OF CATTLE.
By B. H. Ransom, Ph. D.,
Chief of Zoological Division, Bureau of Animal Industry.
The animal parasites of cattle comprise more than a hundred different species, belonging to various groups of the animal kingdom. Fortunately not all these parasites occur in this country—many are uncommon, and many are comparatively harmless. Some forms, however, occur frequently, and some are of distinct importance to the American stockman on account of the damage for which they are responsible. It is these parasites particularly which will be referred to in the present article, and although some forms are discussed which are rare or apparently of little economic importance, most of the minor and unusual parasites and species not found in this country have been omitted from consideration.
FLIES.[11]
Of the various species of flies which infest cattle some are injurious on account of the annoyance, pain, and loss of blood due to their bites, and sometimes also on account of diseases or parasites which are thus transmitted from the blood of diseased animals to that of healthy cattle, while others, which in the winged adult state do not bite, are injurious because they live parasitic on cattle during their larval stages.