152 GENERAL THERAPEUTICS FOR VETERINARIANS 



11. *Euphorbitim. A very irritant epispastic; used in old, 

 chronic surgical affections of the joints, tendons and bones; used on 

 cold-blooded horses and cattle either alone 1 : 10-15 of lard, or as 

 an addition to cantharides ointment (1 : 10-20). 



12. Oleum tiglii. Croton oil. Also a very powerful irritant; 

 used in obstinate chronic rheumatism, arthritis, tendinitis, paresis, 

 etc.; also as a derivant in inflammations of internal organs; must be 

 used cautiously. The concentration for horses is 1 : 30; cattle, 

 1 : 5-10; swine, 1 :2-5; dogs, 1 : 50-100. It is diluted with olive 

 oil, turpentine oil or cantharides ointment. 



3. CAUSTICS 

 S]monyms: Corrosives, cauteries, escharotics, cathaeretics. 



Actions. — ^While the cutaneous irritants produce only the alter- 

 ations of inflammation, without injuring the vitality of the tissues, 

 the caustics cause the death of those living tissues with which they 

 come in contact. The caustic action of the individual drugs is 

 brought about in very different ways and on this basis the following 

 groups of caustics are classified (concerning firing, the actual 

 cautery, see p. 156). 



1. Caustic acids: Nitric, hydrochloric, sulphuric, acetic, chlor- 

 acetic, lactic and salicylic acids and formaldehyde. Of these, the 

 mineral acids and lactic acid operate by coagulating the albumin; 

 they unite with the albumin, forming insoluble acid albuminates, 

 thereby bringing about the precipitation and death of the dis- 

 solved living albumins. Nitric acid, especially, forms with the 

 organic albumin a yellow acid albuminate (xanthoproteic acid, 

 nitrogen compound). The organic acids, particularly acetic acid, 

 also unite with the tissue albumin to form acid albuminates, but 

 these compounds are soluble and are only precipitated when the 

 solution is neutralized. The caustic action of sulphuric acid is 

 due to its strong affinity for water, which it withdraws from the 

 tissues, the latter being carbonized. Salicylic acid and formalde- 

 hyde are peculiar in their action, producing a keratolytic effect, or 

 comification. 



